# Characterisation of phenolic compounds and polysaccharides in strawberry: Cultivar and harvest effects and their correlation with nectar colour stability

Sebastian Rincon, H Murray, M Gössinger, Christian Ginies, Pascale Goupy, Claire Dufour, Olivier Dangles, Carine Le Bourvellec

► To cite this version:

Sebastian Rincon, H Murray, M Gössinger, Christian Ginies, Pascale Goupy, et al.. Characterisation of phenolic compounds and polysaccharides in strawberry: Cultivar and harvest effects and their correlation with nectar colour stability. Food Chemistry, 2025, 473, 10.1016/j.foodchem.2025.143112. hal-04986045

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Submitted on 11 Mar 2025

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<figure><img src="image_1.png" /></figure>

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techniques influence both the composition in phenolic compounds and cell wall components in strawberries (Aaby et al., 2007; Buendía et al., 2010; Carbone et al., 2009; Fernandes et al., 2016).

Accordingly, strawberry diversity offers opportunities to develop products with enhanced sensorial and nutritional properties. Yet studies often focus on anthocyanins, neglecting other phenolic classes like PACs. Similarly, studies on strawberry cell wall polysaccharides are limited with no connection to colour stability. Thus, this study aims to explore the effects of cultivar, ripening, and harvesting conditions on both polysaccharide and polyphenol content and composition in strawberries and their correlation with colour changes in nectar after pilot-scale processing. Thirteen strawberry varieties at two ripening stages and harvest times were characterized for polyphenols and polysaccharides and the effect of these two classes was assessed on the colour stability of the respective strawberry nectars by PCA.

## 2. Methods

### 2.1. Standards and chemicals

Ethanol and acetone were from Fisher Scientific (Strasbourg, France). Acetonitrile of HPLC grade was obtained from VWR International (Radnor, USA). Hexane, methanol, hydrochloric acid and acetic acid were from Merck (Darmstadt, Germany). Sugar standards (arabinose, fucose, galactose, xylose, mannose and rhamnose) were from Fluka (Buchs, Switzerland). Formic acid, sodium carbonate, sodium hydroxide, NaBH₄, N-methylimidazole, acetic anhydride, (+)-catechin, (-)-epicatechin, caffeic acid, para-coumaric acid, quercetin, kaempferol, pelargonidin-3-O-β-glucoside, cyanidin-3-O-β-glucoside, acetyl chloride, menthofuran 95 %, inositol and galacturonic acid were provided by Sigma-Aldrich (Saint Quentin Fallavier, France). Methanol-d₃

was from Acros Organics (Geel, Belgium).

### 2.2. Plant material

Strawberries from Austria were harvested in June and July 2021 in Lower Austria (producer AT Zachamel). From these, 8 different cultivars (Table 1) were collected at different ripening stage (ripe and overripe) and harvest points (early and late), based on the outward colour. Fruits were picked in the morning and frozen in 5 kg plastic bags at -18 °C within 2 h. Strawberries were cored manually while still frozen, then slightly crushed and packed in bags of approximately 300 g. For each cultivar and each batch, flesh without stem was freeze-dried and stored at -20 °C until analysis.

#### 2.2.1. Strawberry nectar

Nectars were produced in Austria from strawberries in June -September 2021. Frozen strawberries from Austria were defrosted for 24 h at 20 °C, and then processed into puree by a rotor mill with 1 mm sieve (Feuma, Gößnitz, Germany). Strawberry purees were mixed with water, citric acid and sugar to produce nectar (40 % puree, 15°Brix, 7.0 g/L Titratable Acidity) and homogenised with a hand blender (Philips, Drachten, Netherlands. (Murray et al., 2023). All samples were pasteurised (80 °C - 10 min) in water bath (Westfalia, Hage, Germany). The samples were stored at 20 °C ± 3 °C in the dark before colour measurements.

### 2.3. Colour measurements

CIELAB parameters L\* (lightness), a\* (red-green), and b\* (yellow-blue) were measured by a Minolta CM-5 spectrophotometer (spectrophotometric method, D65, 30 mm 10°, reflection measurement, gloss

<caption>**Table 1**</caption>

Cultivar, ripening stage, harvest time, acceptance factor values and colour stability group of strawberry and nectar samples defined as in Murray et al., (2021), based on the change of Acceptability Factor, from 1 to 4 from more to less stability.

<table><thead><tr><th>Date</th><th>Cultivar</th><th>Harvest time</th><th>Ripening stage</th><th>Code</th><th>AF0</th><th>AD12</th><th>Stability Group (SG)</th></tr></thead><tbody><tr><td>22.06.2021</td><td>1503 RITMO</td><td>1</td><td>Ripe</td><td>RI1R</td><td>0.80</td><td>0.54</td><td>4</td></tr><tr><td>22.06.2021</td><td>1503 RITMO</td><td>1</td><td>Overripe</td><td>RI1O</td><td>0.85</td><td>0.48</td><td>3</td></tr><tr><td>05.07.2021</td><td>1503 RITMO</td><td>2</td><td>Ripe</td><td>RI2R</td><td>0.85</td><td>0.46</td><td>3</td></tr><tr><td>05.07.2021</td><td>1503 RITMO</td><td>2</td><td>Overripe</td><td>RI2O</td><td>0.95</td><td>0.42</td><td>2</td></tr><tr><td>14.06.2021</td><td>Allegro</td><td>1</td><td>Ripe</td><td>AL1R</td><td>0.74</td><td>0.29</td><td>1</td></tr><tr><td>14.06.2021</td><td>Allegro</td><td>1</td><td>Overripe</td><td>AL1O</td><td>0.81</td><td>0.28</td><td>1</td></tr><tr><td>24.06.2021</td><td>Allegro</td><td>2</td><td>Ripe</td><td>AL2R</td><td>0.85</td><td>0.30</td><td>1</td></tr><tr><td>24.06.2021</td><td>Allegro</td><td>2</td><td>Overripe</td><td>AL2O</td><td>0.90</td><td>0.30</td><td>1</td></tr><tr><td>14.06.2021</td><td>Clery</td><td>1</td><td>Ripe</td><td>CL1R</td><td>0.75</td><td>0.44</td><td>3</td></tr><tr><td>14.06.2021</td><td>Clery</td><td>1</td><td>Overripe</td><td>CL1O</td><td>0.83</td><td>0.46</td><td>3</td></tr><tr><td>24.06.2021</td><td>Clery</td><td>2</td><td>Ripe</td><td>CL2R</td><td>0.85</td><td>0.45</td><td>2</td></tr><tr><td>24.06.2021</td><td>Clery</td><td>2</td><td>Overripe</td><td>CL2O</td><td>0.90</td><td>0.43</td><td>2</td></tr><tr><td>29.06.2021</td><td>Faith</td><td>1</td><td>Ripe</td><td>FA1R</td><td>0.85</td><td>0.38</td><td>2</td></tr><tr><td>29.06.2021</td><td>Faith</td><td>1</td><td>Overripe</td><td>FA1O</td><td>0.93</td><td>0.26</td><td>1</td></tr><tr><td>05.07.2021</td><td>Faith</td><td>2</td><td>Ripe</td><td>FA2R</td><td>0.82</td><td>0.39</td><td>2</td></tr><tr><td>05.07.2021</td><td>Faith</td><td>2</td><td>Overripe</td><td>FA2O</td><td>0.98</td><td>0.31</td><td>1</td></tr><tr><td>22.06.2021</td><td>Limalexia</td><td>1</td><td>Ripe</td><td>LX1R</td><td>0.77</td><td>0.57</td><td>4</td></tr><tr><td>22.06.2021</td><td>Limalexia</td><td>1</td><td>Overripe</td><td>LX1O</td><td>0.81</td><td>0.55</td><td>4</td></tr><tr><td>01.07.2021</td><td>Limalexia</td><td>2</td><td>Ripe</td><td>LX2R</td><td>0.78</td><td>0.54</td><td>4</td></tr><tr><td>01.07.2021</td><td>Limalexia</td><td>2</td><td>Overripe</td><td>LX2O</td><td>0.83</td><td>0.40</td><td>2</td></tr><tr><td>14.06.2021</td><td>Malling Centenary</td><td>1</td><td>Ripe</td><td>MC1R</td><td>0.67</td><td>0.42</td><td>2</td></tr><tr><td>14.06.2021</td><td>Malling Centenary</td><td>1</td><td>Overripe</td><td>MC1O</td><td>0.73</td><td>0.41</td><td>2</td></tr><tr><td>29.06.2021</td><td>Malling Centenary</td><td>2</td><td>Ripe</td><td>MC2R</td><td>0.85</td><td>0.36</td><td>1</td></tr><tr><td>29.06.2021</td><td>Malling Centenary</td><td>2</td><td>Overripe</td><td>MC2O</td><td>0.96</td><td>0.37</td><td>1</td></tr><tr><td>16.06.2021</td><td>Rendezvous</td><td>1</td><td>Ripe</td><td>RV1R</td><td>0.67</td><td>0.23</td><td>1</td></tr><tr><td>16.06.2021</td><td>Rendezvous</td><td>1</td><td>Overripe</td><td>RV1O</td><td>0.77</td><td>0.25</td><td>1</td></tr><tr><td>01.07.2021</td><td>Rendezvous</td><td>2</td><td>Ripe</td><td>RV2R</td><td>0.74</td><td>0.11</td><td>1</td></tr><tr><td>01.07.2021</td><td>Rendezvous</td><td>2</td><td>Overripe</td><td>RV2O</td><td>0.87</td><td>0.17</td><td>1</td></tr><tr><td>16.06.2021</td><td>Sibilla</td><td>1</td><td>Ripe</td><td>SI1R</td><td>0.72</td><td>0.55</td><td>4</td></tr><tr><td>16.06.2021</td><td>Sibilla</td><td>1</td><td>Overripe</td><td>SI1O</td><td>0.78</td><td>0.47</td><td>3</td></tr><tr><td>29.06.2021</td><td>Sibilla</td><td>2</td><td>Ripe</td><td>SI2R</td><td>0.87</td><td>0.47</td><td>3</td></tr><tr><td>29.06.2021</td><td>Sibilla</td><td>2</td><td>Overripe</td><td>SI2O</td><td>0.95</td><td>0.40</td><td>2</td></tr></tbody></table>

AF0: Acceptability Factor after production; AD12: Change in Acceptability Factor after 12 weeks. SG: Stability Group. Stability groups defined as in Murray et al., (2021), based on the change of Acceptability Factor, from 1 to 4 from more to less stability.
excluded, Minolta, Osaka, Japan) on strawberry nectars (Murray et al., 2023). C* (Chroma) and h° (hue angle) were calculated. Acceptance factor (AF) was used as a colour parameter in nectars, calculated as previously reported (Gössinger et al., 2009). Nectar colour was measured after pasteurization, then weekly until the AF was below 0.4 (acceptance limit). Each sample was measured twice.

Indicators for colour stability are the acceptability factor after production (AFO) and the difference in AF between the day of production and week 12 of storage (AD12), respectively. Samples were divided in 4 groups (1–4) according to AD12, with group 1 being the most stable samples and 4 the least stable samples (Table 1).

## 2.4. Preparation of cell walls

Alcohol Insoluble Solids (AIS) were prepared from strawberry powder according to the literature (Renard, 2005). Strawberry powder was dissolved in boiling 70 % ethanol (15 mL g⁻¹). Samples were cooled and mixed overnight at 4 °C. Solids were recovered on a G3 crucible filter. This process was repeated until the filtrates were sugar-free (phenol - H₂SO₄ test). AIS were washed three times with aqueous acetone (60, 80, 100 %), then dried overnight in an oven at 40 °C. Experiments were carried out in triplicate with batches of 5 g of freeze-dried strawberry.

## 2.5. Cell wall chemical composition

### 2.5.1. Hydrolysis

Approximately 10 mg of AIS were pre-hydrolysed with 72 % aqueous H₂SO₄ (250 µL) for 1 h at room temperature (Saeman et al., 1954), before dilution to 1 M H₂SO₄ by the addition of water and an internal standard (inositol). Total hydrolysis (100 °C for 3 h) was also carried out to estimate cellulose content by difference.

### 2.5.2. Neutral sugar composition

Neutral sugars were converted to alditol acetates for analysis (Englyst et al., 1982). The samples were injected in a Gas Chromatography-Flame Ionisation Detector (GC-FID) GC-2010-Pro (Shimadzu, Kyoto, Japan) equipped with a capillary column (30 m × 0.25 mm i.d. coated with DB225 MS, 0.25 µm film thickness). Split mode (1,15 ratio); injector and detector temperatures = 250 °C and 280 °C, respectively; H₂ as carrier gas at 45 cm/s; column flow = 1.3 mL/min; oven temperature = 220 °C (isothermal).

### 2.5.3. Galacturonic acid content

Uronic acids were measured by the meta-hydroxyl-diphenyl assay (Blumenkrantz & Asboe-Hansen, 1973) after Saeman's hydrolysis (§ 2.8.1). The absorbance was read at 520 nm using a UV-visible spectrophotometer (V-530 Jasco, Tokyo, Japan), and concentrations were calculated against a calibration curve with galacturonic acid as external standard.

### 2.5.4. Degree of methylation

The methanol content after saponification was measured by stable isotope dilution assay using headspace- Gas Chromatography-Mass Spectrometry GC-MS (5977 Agilent, Palo Alto, USA)(Renard & Ginies, 2009). The degree of methylation (DM) was calculated as the methanol / galacturonic acid molar ratio.

## 2.6. Extraction of phenolic compounds

Phenolic compounds were analysed by High-Performance Liquid Chromatography coupled with Diode Array Detector (HPLC-DAD) before and after the acidic depolymerisation of PACs in the presence of menthofuran (a process called furanolysis). PACs were thus characterised by their subunit composition, average degree of polymerisation (mDP) and contents. HPLC-DAD analyses of crude methanolic extracts (not submitted to furanolysis) were performed to titrate monomeric

catechins.

Furanolysis was performed on the freeze-dried strawberry powder. Precisely weighted amounts (30 mg) of samples were suspended in 1.2 mL Eppendorf vials containing 400 µL of dry acidified methanol (0.4 mol/L HCl), and 800 µL of a menthofuran solution (50 mL/L dry methanol). The reaction was performed by incubation of samples for 30 min at 40 °C with constant agitation. Samples were cooled on ice in order to stop the reaction. For crude extraction, precisely weighted amounts (70 mg) of samples were dissolved in 1500 µL of dry methanol acidified by acetic acid (10 mL/L). The reaction was carried out in an ultrasonic bath during 15 min. All samples (“furanolysis” and “crude” extracts) were filtered (PTFE, 0.45 µm) and injected (20 µL) into HPLC-DAD. All extractions were performed in triplicate.

## 2.7. Identification of phenolic compounds by HPLC/ESI-MS²

HPLC coupled to ElectroSpray Ionisation Mass Spectrometry (HPLC/ESI-MS²) analysis was performed on an Acquity Ultra performance LC (UPLC) apparatus from Waters (Milford, MA, USA), equipped with a photodiode array detector coupled with a Bruker Daltonics (Bremen, Germany) HCT ultra ion trap mass spectrometer with an electrospray ionisation source. Separations were achieved using a Luna Omega Polar C18 column (50 mm × 2.1 mm × 3 µm column, Phenomenex, Torrance, USA) operated at 30 °C. The mobile phase consisted of water/formic acid (98,2 mL/mL) (eluent A) and acetonitrile (eluent B). The flow rate was 1 mL/min. The elution program was as follows: 3–9 % B (0–5 min); 9–16 % B (5–15 min); 16–50 % B (15–45 min); 50–90 % B (45–48 min); 90–90 % B (48–52 min). Ten µL of samples (“furanolysis” and “crude” extracts) were injected. For polyphenol characterisation, a capillary voltage of 2 kV was used in the negative ion mode. N₂ was used as drying and nebulizing gas with a flow rate of 12 L/min. The desolvation temperature was set at 365 °C and the nebulisation pressure at 0.4 MPa. The ion trap was operated in the Ultrascan mode from m/z 100 to 1000. For anthocyanin characterisation, a capillary voltage of 1.8 kV was used in the positive ion mode under the same conditions.

The characterisation of phenolic compounds in strawberries involved a tentative identification process utilizing UV-vis spectrum, retention time, molecular weight, and MS/MS fragmentation pattern. The interpretation is referred to the cited literature, with discussion limited to instances of special interest.

## 2.8. Quantification of polyphenols by HPLC-DAD

Phenolic compounds were quantified by HPLC-DAD (Prominence system, Shimadzu, Kyoto, Japan) and separations were achieved as described above. Analyses of polyphenols were carried out with or without furanolysis as described in section 2.6 and 2.7. The most prevalent compounds were quantified in the UV-visible region by chromatographic analysis conducted at wavelengths of 280 nm (flavonols), 320 nm (phenolic acids), 360 nm (flavonols), and 520 nm (anthocyanins). Individual compounds were quantified in mg/100 g of fresh weight (FW) by comparison with external standards: (+)-catechin and (−)-epicatechin for flavanols, caffeic and *para*-coumaric acids for phenolic acids, quercetin and kaempferol for flavanols, and pelargoniin-3-O-β-glucoside and cyanidin-3-O-β-glucoside for anthocyanins.

The mDP of PACs was calculated as the following molar ratio: (menthofuran adducts + terminal units - monomers from crude extract) / (terminal units - monomers from crude extract). As shown in Fig. 1, this is equivalent to the molar ratio of peaks (3P + 4P + 7P + 1P-8) / (1P-8).

## 2.9. Statistical analysis

Data analysis was performed using two-way ANOVA, correlation matrix, Principal Component Analysis (PCA) using the statistical software programs XLSTAT (Version 2023.3.1.1416) and RStudio (Version
<figure><img src="image_2.png" /><figcaption>Fig. 1. Chromatographic profile of the phenolic compounds for the studied strawberries at 280 nm, 320 nm, 350 nm and 520 nm (A) PACs after furanolysis (B) Anthocyanins (C) Other phenolic compounds.</figcaption></figure>

4.3.1). For the correlation matrix, a previous analysis of aliased co-
efficients was performed to suppress intercorrelated variables. Redun-
dant variables with low correlation with colour stability were removed.
13 components were assumed in the PCA analysis and 2 components in
total explained most the variance.

**3. Results and discussion**

3.1. *Dry matter content and cell wall yields*

Following freeze-drying, the dry matter content and Alcohol Insol-
uble Solids (AIS), i.e., cell wall contents, were determined. AIS yields
were in the range of those found by (Paniagua et al., 2017), although
(Rosli et al., 2004) reported higher values for dry matter in ‘Camarosa’
cultivar. These results were cultivar and ripening stage dependent, with
values of 120 mg AIS / g FW in unripe strawberries (green stage)

(Table 2).

3.1.1. *Composition of cell walls*

Galacturonic acid was the main component in all cell walls (average
content of 262 mg/g AIS), followed by cellulosic glucose (average
content of 234 mg/g AIS) (Table 2). Besides these two sugars, the neutral
sugars xylose (average content of 77 mg/g AIS), galactose (average
content of 76 mg/g AIS), and arabinose (average content of 57 mg/g
AIS) dominated. Arabinose and galactose are included in the composi-
tion of the pectin side chains, while xylose, together with non-cellulosic
glucose and fucose, are present in hemicelluloses. Mannose and rham-
nose were present in lower contents in strawberry cell walls. These re-
sults were in accordance with previous studies (Broxterman & Schols,
2018; Lee et al., 2011).

Pectins were present in high amounts as shown by the high gal-
acturonic acid content and their degree of methylation range from 46 %
<figure><img src="image_3.png" /><figcaption>Fig. 1. (continued).</figcaption></figure>

(FA2R) to 83 % (LX1R), with an average of 60 % (Table 2). Average values of 70 % have been reported previously (Lefever et al., 2004) and differences are attributed to cultivar selection. The pectin linearity (GalA/Rha ratio) ranged from 7.1 (LX2R) to 36.1 (CL1R) with an average value of 12.4. The rhamnogalacturonan-1 branching ((Gal + Ara)/Rha ratio) ranged from 4.3 (SI2O) to 10 (MC1R) with an average of 7.0. The proportions of arabinose and galactose in the side chains (Ara/ Gal ratio) ranged from 0.4 (CL1O) to 2.0 (SI2R) with an average of 0.9.

### 3.1.2. Cultivar effect on cell walls

Both the dry matter content and the cell wall yields were significantly modified by the cultivar (Table 2). The effect of cultivar was significant for neutral sugars, galacturonic acid contents and pectin characteristics such as DM, linearity, branching and side-chain structure, in accordance with previous findings (Rosli et al., 2004). However, the effect of cultivar was not significant for non-cellulosic glucose.

### 3.1.3. Ripening effect on cell walls

Arabinose and AIS yields, as well as pectin structural characteristics, i.e. (Ara + Gal)/Rha and Ara/Gal ratios, were the most relevant parameters for differentiating ripening stages (Table 2). The significant loss of arabinose ($p \le 0.0001$) during ripening, may indicate decrease in the rhamnogalacturonan branching due to neutral sugar-removing enzymes during ripening (Figueroa et al., 2010). During strawberry growth, cell walls are modified by pectin solubilisation, galactose and arabinose loss, and xyloglucan depolymerisation (Figueroa et al., 2010; Posé et al., 2012; Rosli et al., 2004). These results suggest that ripening is largely related to the hydrolysis of neutral sugars, especially arabinose from pectin side chains (Brummell, 2006).

### 3.1.4. Effect of harvest time on cell walls

All the cell wall components were significantly modified by the harvest time. Cellulosic glucose and rhamnose were the most affected, followed by mannose and arabinose. Pectin structural characteristics, i. e., degree of methylation, linearity, degree of branching and side chain composition, were also significantly modified (Table 2).

Cellulosic glucose, mannose and rhamnose increased significantly in almost all the strawberry cultivars. However, the changes observed in arabinose, xylose, and galactose content depended on the cultivar. Cultivars ‘Allegro’, Clery’, ‘Faith’ and ‘Limalexia’ showed an increase in

the content of these sugars, while cultivars ‘Malling Century’, ‘Rendezvous’ and ‘Sibila’ showed a decrease. Galacturonic acid content also increased significantly with the harvest time, with the exception of cultivar ‘Malling Centenary’. The degree of methylation did not show a clear trend with harvest time. The changes in pectin characteristics were diverse for all cultivars. In general, late harvest time led to low galacturonic acid contents accompanied by loss of neutral sugars, mainly arabinose.

These results could be due to an increase in enzymatic activity (loss in neutral sugars), implying an effect of harvest temperature on cell wall composition. Environment effects have been proposed as important factors on the cell wall modification and firmness of strawberries, due to a possible increase in enzymatic activities during warmer months (Blaszczyk et al., 2022; Kannaujia & Asrey, 2021).

## 3.2. Identification of phenolic compounds by HPLC/ESI-MS² analysis

### 3.2.1. Proanthocyanidins

Strawberries are known to contain a diversity of proanthocyanidins (PACs), owing to the presence of epiafzelechin and (epi)catechin as constitutive units (Gu, Kelm, Hammerstone, Beecher, et al., 2003). Through acidic depolymerisation by furanolysis seven distinct peaks were identified in positive mode ([M]+) (Fig. 1A, Table 3). PACs terminal units are released as free flavan-3-ols. To distinguish native flavan-3-ol monomers naturally present in the medium from flavan-3-ol monomers coming from the terminal units of PACs, a “crude” analysis was also carried out. Peak 1P ($m/z$ 291) was identified as a (+)-catechin terminal unit. However, it was not possible to detect (−)-epicatechin or epiafzelechin as terminal unit. Hence, the collective terminal units are expressed as catechin.

After depolymerisation, PAC extension units are released as carbocations that further react with menthofuran, leading to the formation of flavanol-menthofuran adducts. Peaks 2P and 3P displayed a parent ion at $m/z$ 439 (Billerach et al., 2020), and a major fragment at $m/z$ 287 (MS²), resulting from the Retro-Diels-Alder (RDA) C-ring fission (Liang et al., 2016). The $m/z$ 287 parent ion corresponded to the A-ring fragment of the flavanol unit attached to menthofuran. Hence, peaks 2P and 3P were respectively identified as 3,4-*trans*- and 3,4-*cis*-catechin-menthofuran adducts, in agreement with similar peaks identified in strawberries using thioacidolysis. The 3,4-*cis*-catechin adduct was the
<caption>**Table 2**</caption>

Dry matter (mg/g fresh weight), AIS yield (mg/g fresh weight), neutral sugars, galacturonic acid and methanol contents (mg/g AIS) of the different strawberry cell walls and ANOVA analysis of the effect of cultivar, ripening and harvest time.

<table><thead><tr><th>Code</th><th>Cultivar</th><th>Harv</th><th>Rip</th><th>Dry matter</th><th>AIS yield</th><th>Rha</th><th>Fuc</th><th>Ara</th><th>Xyl</th><th>Man</th><th>Gal</th><th>NCGlc</th><th>CGlc</th><th>GalU</th><th>MeOH</th><th>Total</th><th>DM (%)</th><th>GalA/ Rha</th><th>(Ara + Gal)/ Rha</th><th>Ara/ Gal</th></tr></thead><tbody><tr><td>AL1R</td><td>Allegro</td><td>1</td><td>R</td><td>78.3</td><td>11.8</td><td>18</td><td>12</td><td>61</td><td>77</td><td>30</td><td>93</td><td>38</td><td>172</td><td>314</td><td>27</td><td>843</td><td>48.4</td><td>14.1</td><td>8.2</td><td>0.7</td></tr><tr><td>AL10</td><td>Allegro</td><td>1</td><td>O</td><td>85.7</td><td>11.3</td><td>18</td><td>10</td><td>53</td><td>78</td><td>32</td><td>101</td><td>23</td><td>164</td><td>270</td><td>37</td><td>786</td><td>78.6</td><td>12.3</td><td>8.2</td><td>0.6</td></tr><tr><td>AL2R</td><td>Allegro</td><td>2</td><td>R</td><td>113.8</td><td>15.3</td><td>24</td><td>14</td><td>75</td><td>84</td><td>35</td><td>101</td><td>20</td><td>311</td><td>323</td><td>33</td><td>1021</td><td>57.3</td><td>11.2</td><td>7.3</td><td>0.8</td></tr><tr><td>AL20</td><td>Allegro</td><td>2</td><td>O</td><td>101.1</td><td>13.1</td><td>20</td><td>14</td><td>52</td><td>90</td><td>25</td><td>89</td><td>21</td><td>323</td><td>326</td><td>30</td><td>990</td><td>51.7</td><td>13.4</td><td>6.8</td><td>0.6</td></tr><tr><td>CL1R</td><td>Clery</td><td>1</td><td>R</td><td>101.1</td><td>14.5</td><td>6</td><td>3</td><td>23</td><td>31</td><td>12</td><td>23</td><td>7</td><td>127</td><td>276</td><td>32</td><td>540</td><td>63.1</td><td>36.1</td><td>7.2</td><td>1.1</td></tr><tr><td>CL10</td><td>Clery</td><td>1</td><td>O</td><td>110.7</td><td>16.6</td><td>15</td><td>9</td><td>31</td><td>67</td><td>27</td><td>83</td><td>31</td><td>144</td><td>218</td><td>27</td><td>654</td><td>69.3</td><td>11.8</td><td>7.1</td><td>0.4</td></tr><tr><td>CL2R</td><td>Clery</td><td>2</td><td>R</td><td>117.1</td><td>17.2</td><td>20</td><td>13</td><td>65</td><td>75</td><td>43</td><td>85</td><td>22</td><td>327</td><td>333</td><td>30</td><td>1015</td><td>50.2</td><td>13.5</td><td>7.3</td><td>0.8</td></tr><tr><td>CL20</td><td>Clery</td><td>2</td><td>O</td><td>118.2</td><td>17.0</td><td>20</td><td>12</td><td>52</td><td>86</td><td>30</td><td>73</td><td>31</td><td>293</td><td>291</td><td>30</td><td>918</td><td>56.9</td><td>12.2</td><td>6.2</td><td>0.8</td></tr><tr><td>FA1R</td><td>Faith</td><td>1</td><td>R</td><td>78.0</td><td>14.3</td><td>19</td><td>6</td><td>32</td><td>60</td><td>24</td><td>66</td><td>16</td><td>271</td><td>241</td><td>32</td><td>768</td><td>74.0</td><td>10.4</td><td>4.9</td><td>0.5</td></tr><tr><td>FA10</td><td>Faith</td><td>1</td><td>O</td><td>89.1</td><td>12.2</td><td>19</td><td>7</td><td>33</td><td>65</td><td>25</td><td>67</td><td>19</td><td>277</td><td>244</td><td>29</td><td>785</td><td>64.9</td><td>10.8</td><td>5.2</td><td>0.6</td></tr><tr><td>FA2R</td><td>Faith</td><td>2</td><td>R</td><td>94.9</td><td>18.5</td><td>20</td><td>7</td><td>41</td><td>88</td><td>24</td><td>77</td><td>19</td><td>318</td><td>315</td><td>26</td><td>935</td><td>46.0</td><td>12.9</td><td>5.7</td><td>0.6</td></tr><tr><td>FA20</td><td>Faith</td><td>2</td><td>O</td><td>91.1</td><td>17.7</td><td>18</td><td>8</td><td>29</td><td>67</td><td>25</td><td>69</td><td>26</td><td>285</td><td>329</td><td>30</td><td>886</td><td>47.9</td><td>15.3</td><td>5.3</td><td>0.5</td></tr><tr><td>LX1R</td><td>Limalexia</td><td>1</td><td>R</td><td>91.0</td><td>14.5</td><td>20</td><td>11</td><td>75</td><td>79</td><td>26</td><td>99</td><td>13</td><td>221</td><td>224</td><td>26</td><td>793</td><td>83.1</td><td>9.3</td><td>8.6</td><td>0.8</td></tr><tr><td>LX10</td><td>Limalexia</td><td>1</td><td>O</td><td>95.5</td><td>14.5</td><td>9</td><td>3</td><td>29</td><td>26</td><td>13</td><td>28</td><td>7</td><td>142</td><td>225</td><td>31</td><td>512</td><td>73.6</td><td>22.0</td><td>6.7</td><td>1.1</td></tr><tr><td>LX2R</td><td>Limalexia</td><td>2</td><td>R</td><td>117.1</td><td>15.2</td><td>25</td><td>12</td><td>61</td><td>75</td><td>25</td><td>93</td><td>28</td><td>304</td><td>213</td><td>29</td><td>865</td><td>76.6</td><td>7.1</td><td>6.1</td><td>0.7</td></tr><tr><td>LX20</td><td>Limalexia</td><td>2</td><td>O</td><td>114.9</td><td>16.2</td><td>21</td><td>12</td><td>82</td><td>82</td><td>28</td><td>97</td><td>26</td><td>293</td><td>223</td><td>32</td><td>896</td><td>77.8</td><td>8.7</td><td>8.3</td><td>0.9</td></tr><tr><td>MC1R</td><td>Malling Centenary</td><td>1</td><td>R</td><td>80.0</td><td>12.0</td><td>15</td><td>10</td><td>65</td><td>74</td><td>27</td><td>90</td><td>18</td><td>157</td><td>290</td><td>34</td><td>780</td><td>52.6</td><td>15.7</td><td>10.0</td><td>0.8</td></tr><tr><td>MC10</td><td>Malling Centenary</td><td>1</td><td>O</td><td>84.3</td><td>11.7</td><td>16</td><td>10</td><td>59</td><td>70</td><td>30</td><td>101</td><td>16</td><td>178</td><td>306</td><td>38</td><td>823</td><td>46.9</td><td>15.6</td><td>9.6</td><td>0.6</td></tr><tr><td>MC2R</td><td>Malling Centenary</td><td>2</td><td>R</td><td>106.3</td><td>14.6</td><td>20</td><td>11</td><td>58</td><td>70</td><td>26</td><td>72</td><td>23</td><td>278</td><td>268</td><td>32</td><td>857</td><td>64.8</td><td>11.2</td><td>6.5</td><td>0.9</td></tr><tr><td>MC20</td><td>Malling Centenary</td><td>2</td><td>O</td><td>86.5</td><td>12.7</td><td>22</td><td>12</td><td>45</td><td>78</td><td>30</td><td>65</td><td>23</td><td>295</td><td>277</td><td>32</td><td>880</td><td>63.6</td><td>10.3</td><td>4.9</td><td>0.8</td></tr><tr><td>RI1R</td><td>1503 Ritmo</td><td>1</td><td>R</td><td>98.9</td><td>19.2</td><td>17</td><td>5</td><td>93</td><td>73</td><td>21</td><td>59</td><td>19</td><td>86</td><td>227</td><td>19</td><td>619</td><td>46.3</td><td>10.9</td><td>9.0</td><td>1.7</td></tr><tr><td>RIO1</td><td>1503 Ritmo</td><td>1</td><td>O</td><td>101.6</td><td>16.4</td><td>15</td><td>8</td><td>80</td><td>74</td><td>16</td><td>69</td><td>24</td><td>100</td><td>197</td><td>19</td><td>602</td><td>55.7</td><td>10.8</td><td>9.9</td><td>1.3</td></tr><tr><td>RIR2</td><td>1503 Ritmo</td><td>2</td><td>R</td><td>130.6</td><td>16.5</td><td>21</td><td>10</td><td>57</td><td>92</td><td>24</td><td>76</td><td>29</td><td>305</td><td>215</td><td>23</td><td>853</td><td>58.1</td><td>8.3</td><td>6.2</td><td>0.8</td></tr><tr><td>RIO2</td><td>1503 Ritmo</td><td>2</td><td>O</td><td>115.7</td><td>18.7</td><td>25</td><td>10</td><td>49</td><td>82</td><td>29</td><td>61</td><td>29</td><td>290</td><td>228</td><td>27</td><td>829</td><td>65.0</td><td>7.7</td><td>4.5</td><td>0.9</td></tr><tr><td>RVR1</td><td>Rendezvous</td><td>1</td><td>R</td><td>89.3</td><td>13.7</td><td>22</td><td>12</td><td>80</td><td>115</td><td>26</td><td>112</td><td>15</td><td>264</td><td>208</td><td>21</td><td>876</td><td>64.6</td><td>7.7</td><td>8.4</td><td>0.8</td></tr><tr><td>RVO1</td><td>Rendezvous</td><td>1</td><td>O</td><td>93.3</td><td>13.5</td><td>17</td><td>11</td><td>57</td><td>103</td><td>19</td><td>87</td><td>24</td><td>209</td><td>211</td><td>28</td><td>765</td><td>54.9</td><td>10.0</td><td>8.1</td><td>0.7</td></tr><tr><td>RV2R</td><td>Rendezvous</td><td>2</td><td>R</td><td>89.1</td><td>11.8</td><td>20</td><td>11</td><td>56</td><td>89</td><td>26</td><td>86</td><td>24</td><td>310</td><td>296</td><td>34</td><td>952</td><td>63.5</td><td>12.5</td><td>7.1</td><td>0.7</td></tr><tr><td>RV20</td><td>Rendezvous</td><td>2</td><td>O</td><td>106.4</td><td>12.3</td><td>21</td><td>13</td><td>53</td><td>82</td><td>28</td><td>101</td><td>25</td><td>296</td><td>264</td><td>31</td><td>913</td><td>64.0</td><td>10.4</td><td>7.1</td><td>0.6</td></tr><tr><td>SI1R</td><td>Sibila</td><td>1</td><td>R</td><td>94.9</td><td>17.0</td><td>16</td><td>10</td><td>67</td><td>80</td><td>28</td><td>57</td><td>28</td><td>209</td><td>223</td><td>27</td><td>745</td><td>60.1</td><td>11.6</td><td>7.9</td><td>1.3</td></tr><tr><td>SI10</td><td>Sibila</td><td>1</td><td>O</td><td>65.5</td><td>10.5</td><td>17</td><td>11</td><td>68</td><td>96</td><td>32</td><td>62</td><td>21</td><td>237</td><td>206</td><td>22</td><td>773</td><td>74.0</td><td>10.3</td><td>7.9</td><td>1.2</td></tr><tr><td>SI2R</td><td>Sibila</td><td>2</td><td>R</td><td>130.0</td><td>18.8</td><td>19</td><td>11</td><td>59</td><td>76</td><td>30</td><td>33</td><td>22</td><td>291</td><td>306</td><td>34</td><td>881</td><td>61.1</td><td>13.1</td><td>4.9</td><td>2.0</td></tr><tr><td>SI20</td><td>Sibila</td><td>2</td><td>O</td><td>123.3</td><td>14.9</td><td>29</td><td>20</td><td>73</td><td>92</td><td>50</td><td>50</td><td>29</td><td>310</td><td>300</td><td>23</td><td>976</td><td>64.5</td><td>8.5</td><td>4.3</td><td>1.6</td></tr><tr><td colspan="2">Pooled SD</td><td></td><td></td><td>2.4</td><td>7.4</td><td>1.2</td><td>0.9</td><td>3.6</td><td>4.5</td><td>2.0</td><td>5.3</td><td>3.9</td><td>14.2</td><td>17.7</td><td>1.2</td><td>51.1</td><td>3.6</td><td>0.4</td><td>0.4</td><td>0.0</td></tr><tr><td colspan="2">Statistics: F-value and significance</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td colspan="2">Cultivar</td><td></td><td></td><td>51***</td><td>11***</td><td>4***</td><td>11***</td><td>14***</td><td>11***</td><td>5***</td><td>11***</td><td>1</td><td>16***</td><td>14***</td><td>7***</td><td>4**</td><td>6***</td><td>11***</td><td>7***</td><td>69***</td></tr><tr><td colspan="2">Harvest time</td><td></td><td></td><td>330***</td><td>16***</td><td>87***</td><td>48***</td><td>1</td><td>11**</td><td>16***</td><td>1</td><td>9**</td><td>479***</td><td>43***</td><td>9**</td><td>45***</td><td>0***</td><td>105***</td><td>14***</td><td>16***</td></tr><tr><td colspan="2">Ripening stage</td><td></td><td></td><td>0</td><td>6*</td><td>1</td><td>1</td><td>13***</td><td>0</td><td>0</td><td>1</td><td>2</td><td>1</td><td>2</td><td>4</td><td>0</td><td>2</td><td>3</td><td>2***</td><td>14***</td></tr><tr><td colspan="2">Cultivar*Harvest time</td><td></td><td></td><td>10***</td><td>3**</td><td>5***</td><td>4**</td><td>10***</td><td>9***</td><td>4**</td><td>5***</td><td>3**</td><td>15***</td><td>6***</td><td>8***</td><td>2</td><td>9***</td><td>12***</td><td>7***</td><td>11***</td></tr><tr><td colspan="2">Cultivar*Ripening stage</td><td></td><td></td><td>5***</td><td>1</td><td>6***</td><td>3*</td><td>1</td><td>5***</td><td>2</td><td>3**</td><td>3*</td><td>3*</td><td>1</td><td>2</td><td>1</td><td>3</td><td>1***</td><td>8***</td><td>7***</td></tr><tr><td colspan="2">Harvest time*Ripening stage</td><td></td><td></td><td>32***</td><td>1</td><td>1</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td><td>1</td><td>1</td><td>0</td><td>0</td><td>1</td><td>1</td><td>2***</td></tr></tbody></table>

Harv: harvest time, Rip: ripening stage, R: Ripe; O: Overripe, AIS: Alcohol Insoluble Solids, Rha: rhamnose, Fuc: fucose, Ara: arabinose, Xyl: xylose, Man: mannose, Gal: galactose, Glc: glucose, GalU: galacturonic acid, CGlc: glucose from cellulose, NCGlc: non-cellulosic glucose, MeOH: methanol, DM: degree of methylation. Ratios are calculated using the neutral sugar content and expressed in mol%. The ratio between different sugars can contribute to understand information on polymer nature. The ratios of GalA/Rha, (Ara + Gal)/Rha and Ara/Gal are characteristic for pectin backbone homogalacturonan vs rhamnogalacturonan contribution, the branching of RG-I and the proportion of arabinose vs galactose, respectively. Pooled SD: pooled standard deviation (degree of freedom: 64), Fisher's value, *p* ≤ 0.05: *, p ≤ 0.01: **, p ≤ 0.001: ***.
<table><caption>**Table 3**
Phenolic compounds detected by UPLC/DAD/ESI-MS² in 8 strawberry cultivars.</caption><thead><tr><th>Peak</th><th>Retention time (min)</th><th>lambda max (nm)</th><th>MW</th><th>[M-H]<sup>-</sup>/[M]<sup>+</sup> (m/z)</th><th>MS<sup>2</sup> ions (m/z)</th><th>Tentative identification</th></tr></thead><tbody><tr><td colspan="7"><strong>Flavan-3-ols</strong></td></tr><tr><td>1</td><td>4.8</td><td>280</td><td>866</td><td><strong>865</strong></td><td>695/577/543/449/289/287</td><td>B-type proanthocyanidin trimer<sup>acd</sup></td></tr><tr><td>5</td><td>8.8</td><td>278</td><td>578</td><td><strong>577</strong></td><td>451/425/407/289</td><td>B-type proanthocyanidin dimer<sup>acd</sup></td></tr><tr><td>6</td><td>9.4</td><td>278</td><td>578</td><td><strong>577</strong></td><td>451/425/407/289</td><td>B-type proanthocyanidin dimer<sup>acd</sup></td></tr><tr><td>7</td><td>10.1</td><td>278</td><td>866</td><td><strong>865</strong></td><td>847/739/713/695/577/449/289/287</td><td>B-type proanthocyanidin trimer<sup>acd</sup></td></tr><tr><td>8</td><td>10.2</td><td>278</td><td>290</td><td><strong>289</strong></td><td>245/205</td><td>(+)-Catechin<sup>acd</sup></td></tr><tr><td>11</td><td>12.3</td><td>-</td><td>562</td><td><strong>561</strong></td><td>543/435/407/289</td><td>(Epi)afzelechin-(epi)catechin-<sup>acdgh</sup></td></tr><tr><td colspan="7"><strong>PACs</strong></td></tr><tr><td>1P</td><td>10.2</td><td>278</td><td>290</td><td>291</td><td>273/165/139/123</td><td>(+)-Catechin<sup>g</sup></td></tr><tr><td>2P</td><td>35.9</td><td>278</td><td>438</td><td>439</td><td>287/271/151</td><td>Catechin-menthofuran isomer I<sup>ef</sup></td></tr><tr><td>3P</td><td>37</td><td>278</td><td>438</td><td>439</td><td>287/271/151</td><td>Catechin-menthofuran isomer II<sup>ef</sup></td></tr><tr><td>4P</td><td>39.2</td><td>278</td><td>438</td><td>439</td><td>287/271/151</td><td>Epicatechin-menthofuran isomer I<sup>ef</sup></td></tr><tr><td>5P</td><td>39.6</td><td>278</td><td>438</td><td>439</td><td>287/271/151</td><td>Epicatechin-menthofuran isomer II<sup>ef</sup></td></tr><tr><td>6P</td><td>40</td><td>274</td><td>422</td><td>423</td><td>287/273/255/151</td><td>(Epi)afzelechin-menthofuran isomer I<sup>ef</sup></td></tr><tr><td>7P</td><td>42.4</td><td>274</td><td>422</td><td>423</td><td>287/273/255/151</td><td>(Epi)afzelechin-menthofuran isomer II<sup>ef</sup></td></tr><tr><td colspan="7"><strong>Anthocyanins</strong></td></tr><tr><td>1A</td><td>12.7</td><td>-</td><td>706</td><td><strong>705</strong></td><td>543, 407, 313</td><td>(Epi)afzelechin-(4α- > 8)-pelargonidin 3-O-β-glucoside<sup>g</sup></td></tr><tr><td>2A</td><td>13.4</td><td>519</td><td>449</td><td><strong>449</strong></td><td>287</td><td>Cyanidin-3-O-β-glucoside<sup>acd</sup></td></tr><tr><td>3A</td><td>15.2</td><td>501</td><td>433</td><td><strong>433</strong></td><td>271</td><td>Pelargonidin-3-O-β-glucoside<sup>acd</sup></td></tr><tr><td>4A</td><td>15.9</td><td>499</td><td>579</td><td><strong>579</strong></td><td>433/271</td><td>Pelargonidin-3-O-β-rutinoside<sup>acd</sup></td></tr><tr><td>5A</td><td>16.7</td><td>-</td><td>501</td><td><strong>501</strong></td><td>339</td><td>5-Carboxylypyranopelargonidin-3-O-glucoside<sup>ci</sup></td></tr><tr><td>6A</td><td>18.2</td><td>-</td><td>535</td><td><strong>535</strong></td><td>287</td><td>Cyanidin-3-O-malonylglucoside<sup>aci</sup></td></tr><tr><td>7A</td><td>19.8</td><td>501</td><td>519</td><td><strong>519</strong></td><td>271</td><td>Pelargonidin-3-O-malonylglucoside<sup>aci</sup></td></tr><tr><td>8A</td><td>21.8</td><td>-</td><td>475</td><td><strong>475</strong></td><td>271</td><td>Pelargonidin-3-O-acetylglucoside<sup>acd</sup></td></tr><tr><td colspan="7"><strong>Flavonols</strong></td></tr><tr><td>14</td><td>20.8</td><td>356</td><td>478</td><td><strong>477</strong></td><td>301</td><td>Quercetin-3-O-glucuronide<sup>acd</sup></td></tr><tr><td>15</td><td>22.2</td><td>-</td><td>594</td><td><strong>593</strong></td><td>285</td><td>Kaempferol-3-O-p-coumaroylglucoside<sup>acd</sup></td></tr><tr><td>17</td><td>23.2</td><td>-</td><td>462</td><td><strong>461</strong></td><td>315, 285</td><td>Kaempferol-3-O-glucuronide<sup>ad</sup></td></tr><tr><td>20</td><td>24.8</td><td>-</td><td>534</td><td><strong>533</strong></td><td>489/285</td><td>Kaempferol -3-O-malonylglucoside<sup>ac</sup></td></tr><tr><td colspan="7"><strong>Phenolic acids</strong></td></tr><tr><td>3</td><td>6.4</td><td>253</td><td>300</td><td><strong>299</strong></td><td>239/179/137</td><td>p-hydroxybenzoic acid hexoside<sup>c</sup></td></tr><tr><td>4</td><td>8</td><td>-</td><td>342</td><td><strong>341</strong></td><td>179/161/135</td><td>Caffeic acid-O-hexoside<sup>cd</sup></td></tr><tr><td>9</td><td>10.7</td><td>315</td><td>326</td><td><strong>325</strong></td><td>265/205/187/163/145/119</td><td>p-Coumaroylhexose<sup>cd</sup></td></tr><tr><td>10</td><td>11.2</td><td>306</td><td>326</td><td><strong>325</strong></td><td>265/205/187/163/145/119</td><td>p-Coumaric acid-O-hexoside<sup>cd</sup></td></tr><tr><td>13</td><td>20.4</td><td>-</td><td>358</td><td><strong>357</strong></td><td>195</td><td>Dihydroferulic acid hexoside<sup>b</sup></td></tr><tr><td>18</td><td>23.4</td><td>252/344</td><td>462</td><td><strong>461</strong></td><td>315</td><td>Methylellagic acid deoxyhexoside<sup>d</sup></td></tr><tr><td colspan="7"><strong>Other Phenolics</strong></td></tr><tr><td>2</td><td>6</td><td>-</td><td>784</td><td><strong>783</strong></td><td>481/301</td><td>Bis-HHDP-O-hexose (Ellagitannin)<sup>bcd</sup></td></tr><tr><td>16</td><td>22.9</td><td>284</td><td>610</td><td><strong>609</strong></td><td>301</td><td>Hesperetin rutinoside (Flavanone)<sup>d</sup></td></tr><tr><td>19</td><td>24</td><td>280</td><td>436</td><td><strong>435</strong></td><td>273/167</td><td>Phloretin-O-hexoside (Dihydrochalcone)<sup>d</sup></td></tr><tr><td colspan="7"><strong>Others</strong></td></tr><tr><td>12</td><td>19.5</td><td>284</td><td>310</td><td><strong>309</strong></td><td>147</td><td>Cinnamoylhexose<sup>ad</sup></td></tr></tbody></table>

Ionisation in negative mode for all compounds except for anthocyanins and PACs in positive mode. PACs characterized by acid depolymerisation with menthofuran. The main fragment in MS² is given in bold. a Aaby et al., 2012; b Aaby et al., 2007; c Kajdzanoska et al., 2010; d Spinola et al., 2015; e Billerach et al., 2020; f Gu et al., 2003; g Lopez da Silva et al., 2007.

predominant product and eluted later than the 3,4-*trans*-isomer (Gu, Kelm, Hammerstone, Beecher, et al., 2003). Peaks 4P and 5P exhibited similar characteristics to peaks 2P and 3P. Both with *m/z* 439 and the characteristic MS² fragment at *m/z* 287 (RDA). These adducts have been previously observed by depolymerising procyanidin B2 (Billerach et al., 2020; Gu, Kelm, Hammerstone, Beecher, et al., 2003). Thus, peak 4P was attributed to 3,4-*trans*-epicatechin-menthofuran (Gu, Kelm, Hammerstone, Beecher, et al., 2003; Karonen et al., 2007) by comparison with the only adduct detected in the presence of phloroglucinol while peak 5P was tentatively identified as 3,4-*cis*-epicatechin-menthofuran. Peaks 6P and 7P displayed a parent ion at *m/z* 423 and fragment ions at

*m/z* 287, 273, 255 and 151. The *m/z* 287 fragment, resulting from the loss of 136 Da (RDA fission), indicates a B ring with a single OH group (Gu, Kelm, Hammerstone, Beecher, et al., 2003). Quinone methide (QM) fragmentation produced ions at 273 (confirming epiafzelechin as the extension unit) and 151 (menthofuran), as observed by (Billerach et al., 2020). Hence, Peaks 6P and 7P were identified as 3,4-*trans*- and 3,4-*cis*-epiafzelechin-menthofuran adducts by analogy with catechin-menthofuran adducts.

### 3.2.2. Anthocyanins

The anthocyanins detected in positive mode ([M]+) (peaks 2 A-4 A,
6 A-8 A, Fig. 1B, Table 3) were pelargonidin and cyanidin glucosides and malonylglucosides as well as pelargonidin rutinoside and acetylgluco- side. All have been previously reported in strawberries (Aaby et al., 2005, 2007; da Silva et al., 2007; Määttä-Riihinen et al., 2004). An additional pigment was identified at 520 nm. Peak 1 A showed a parent ion at *m/z* 705 with a MS² fragment at *m/z* 543 (Fossen et al., 2004). It was identified as epiafzelechin-(4α → 8)-pelargonidin-3-O-β-glucopyranoside through NMR analysis. Peak 5 A (*m/z* 501) is assigned to a pyrano derivative resulting from the reaction between pelargonidin-3-O-β-glucoside and pyruvic acid.

### 3.2.3. Flavonols

Peak 14 (Fig. 1B, Table 3) with a parent ion at *m/z* 477 and a main fragment at *m/z* 301 (glucuronic acid loss of 176 amu) was identified as quercetin-3-O-glucuronide, a major flavonol in strawberry (Aaby et al., 2012; Buendía et al., 2010). Peaks 15 (*m/z* 593), 17 (*m/z* 461) and 20 (*m/z* 533) were all kaempferol glycoside derivatives, with a daughter ion at *m/z* 285. Peak 15 with a loss of 308 amu (coumaroylhexose) was identified as kaempferol-3-O-*p*-coumaroylglucoside (Kajdżanoska et al., 2010). Peak 17 with a loss of 176 (glucuronic acid moiety) was identified as kaempferol-3-O-glucuronide. Peak 20 with a main daughter ion at *m/z* 489 (loss of CO₂) and an additional loss of acetyl hexose (204 amu) was tentatively identified as kaempferol-3-O-malonylglucoside (Aaby et al., 2007; Aaby et al., 2012).

### 3.2.4. Phenolic Acids

Peak 3 (Fig 1C, Table 3, *m/z* 299 with a fragment at *m/z* 137 featuring a loss of hexose) was identified as a *p*-hydroxybenzoic acid hexoside in agreement with the literature (Aaby et al., 2007; Kajdżanoska et al., 2010). Peaks 4, 9, 10, 13, were all identified as derivatives of hydroxycinnamic acid. Peak 4 is a caffeic acid-O-hexoside. Peaks 9 and 10 are isomeric *p*-coumaric acid hexosides with glycosylation at the carboxyl or phenolic group, respectively. Peak 13, with a parent ion at *m/z* 357 and fragment ions at *m/z* 195 (loss of hexose) and 151, was identified as a dihydroferulic acid hexoside. Peak 18 was identified as a deoxyhexoside of methylellagic acid (Spínola et al., 2015).

### 3.2.5. Other phenolic compounds

Peak 2 (Fig. 1B, Table 3) *m/z* 783 with fragment ions at *m/z* 481 (loss of HHDP group) and 301 (ellagic acid) was identified as bis-HHDP-O-hexose, a tetraester of hexose with 2 equivalents of hexahydroxydiphenic acid, as reported previously (Kajdżanoska et al., 2010). Peak 16 (*m/z* 609, fragment ion at *m/z* 301 consistent with a loss of rutinoside) was identified as hesperetin rutinoside. Peak 19 (*m/z* 435, MS² fragment at *m/z* 273 featuring a loss of hexose) was characterized as phloretin-O-hexoside (phloridzin), and previously identified in strawberry (Spínola et al., 2015).

### 3.2.6. Others

Peak 12 with *m/z* 309 was identified as cinnamoyl hexose, previously detected in strawberry on the basis of UV max (284 nm) (Aaby et al., 2012).

## 3.3. Quantification of phenolic compounds

Quantification of phenolic compounds and characterisation of PACs is presented for all cultivars from Table 1 (Tables 4 and 5). PACs were the predominant phenolic compounds (by weight), followed by anthocyanins, phenolic acids, monomeric flavan-3-ols, and finally flavonols (Table 5). These results are in agreement with some previous works (Buendía et al., 2010; Salazar-Orbea et al., 2023) but in contrary with others (Aaby et al., 2012; Määttä-Riihinen et al., 2004). These discrepancies may be due to differences in extraction methods, which often tend to underestimate total PACs, and from the tentative identification of phenolics, introducing further deviations in the total content

(Kajdżanoska et al., 2011).

The concentration of total flavan-3-ols (PACs and monomers) varied between 76.9 and 151.2 mg/100 g FW (Table 4), as stated in previous works (Buendía et al., 2010; Salazar-Orbea et al., 2021). Total flavan-3-ols comprised 94 % of PACs and only 6 % of monomers. The mDP of PACs ranged from 6.1 to 12.3, with an average value of 8.8. PACs units were composed of (+)-catechin, both as terminal and extension unit, (-)-epicatechin and epiafzelechin, which were only found as extension units (Almeida et al., 2007; Buendía et al., 2010; Gu, Kelm, Hammerstone, Beecher, et al., 2003). The average content of (+)-catechin as terminal units, (+)-catechin as extension units, (-)-epicatechin as extension units, and epiafzelechin as extension units were 12.1 %, 21.7 %, 58.5 %, and 7.8 %, respectively (Table 5) (Gu, Kelm, Hammerstone, Zhang, et al., 2003). Slightly different values were reported, probably due to cultivar differences (Buendía et al., 2010). Our results suggest a specificity of (+)-catechin as unit of initiation.

Total anthocyanin content in strawberries ranged from 17.7 to 81.7 mg/100 g FW, with an average of 42.5 mg/100 g FW (Table 4), in line with the literature (Aaby et al., 2012; Buendía et al., 2010; da Silva et al., 2007; Määttä-Riihinen et al., 2004). Pelargonidin-3-O-β-glucoside was the main anthocyanin, followed by pelargonidin-3-O-malonylglucoside, pelargonidin-3-O-β-rutinoside, cyanidin-3-O-β-glucoside, and cyanidin-3-O-malonylglucoside as reported in the literature. In average, total phenolic acid derivatives content was 7.3 mg/100 g FW. The main compound was *p*-coumaroyl hexose, followed by caffeic acid hexoside, dihydroferulic acid hexoside, and finally methylellagic acid deoxyhexoside, in agreement with the literature. As for total flavonols, the average content was 3.7 mg/100 g FW (Aaby et al., 2012).

In line with these results, some studies have reported that in free and conjugated forms, ellagitannins were only minor polyphenols in strawberries (Aaby et al., 2012; Buendía et al., 2010; Salazar-Orbea et al., 2021). However, others described higher contents (Aaby et al., 2007; Määttä-Riihinen et al., 2004). Ellagitannins are mainly present in the seeds, and crushing the fruit may have left the seeds intact, limiting their extraction. Moreover, differences could be due to extraction methods, as methanol as extraction solvent, may have favoured anthocyanins and proanthocyanidins, compared to other solvents more suitable for ellagitannins (Määttä-Riihinen et al., 2004).

### 3.3.1. Cultivar effect on polyphenols

The cultivar effect was significant (*p* ≤ 0.0001) for all phenolic compounds, especially for anthocyanins (Table 4). The composition of polyphenols in all samples was consistent with previous works (Buendía et al., 2010; Salazar-Orbea et al., 2021). However, the concentration of each group depended on the cultivar (Aaby et al., 2012; Buendía et al., 2010; da Silva et al., 2007).

Both the proanthocyanidin composition and degree of polymerisation varied depending on the cultivar (Table 5). The average content of (+)-catechin as terminal unit ranged from 8.2 % in cultivar 'Faith' to 16,5 % in 'Clery', and as extension units from 11.6 % in 'Faith' to 24.0 in 'Limalexia', respectively. The content of (-)-epicatechin as extension unit varied between 52.6 % in 'Limalexia' and 72.4 % in 'Faith'. Epiafzelechin as extension unit ranged from 5.4 % in '1503 Ritmo' to 10.7 % in 'Allegro'.

The anthocyanin profile was similar among all the cultivars (Table 4), as stated in section 3.3. Pelargonidin-3-O-malonylglucoside was the second most abundant anthocyanin, present in almost all the cultivars. However, in other studies with commercial cultivars, it is only a minor compound (Buendía et al., 2010; da Silva et al., 2007). This suggests a strong influence of cultivar on anthocyanin composition. Cyanidin-3-O-malonylglucoside and pelargonidin-3-O-β-rutinoside were below the detection signal in 'Allegro' cultivar.

The effect of the cultivar on phenolic acids was less pronounced compared with anthocyanins and flavonols (Buendía et al., 2010). Quercetin-3-O-glucuronide was the predominant flavonol, and the concentrations of kaempferol-3-O-glucuronide and kaempferol-3-O-
<caption>**Table 4**</caption>

Contents in major phenolic compounds (mg/100 g FW) and ANOVA analysis for the effects of cultivar, ripening stage and harvest time.

<table><thead><tr><th>Code</th><th>Cultivar</th><th>Harv</th><th>Rip</th><th>CAT</th><th>PACS</th><th>MEA dhex</th><th>pCoum Hex</th><th>DHF Hex</th><th>CAH</th><th>Q 3GlcU</th><th>Kpf 3CoumHex</th><th>Kpf 3GlcU</th><th>Kpf 3MalGlc</th><th>Cy 3Glc</th><th>Cy 3MalGlc</th><th>Plg 3Glc</th><th>Plg3 Rut</th><th>Plg3 MalGlc</th></tr></thead><tbody><tr><td>AL1R</td><td>Allegro</td><td>1</td><td>R</td><td>8.1</td><td>81.9</td><td>0.60</td><td>2.2</td><td>0.0</td><td>1.2</td><td>2.3</td><td>0.1</td><td>0.8</td><td>0.3</td><td>0.8</td><td>0.1</td><td>30.1</td><td>0.0</td><td>3.4</td></tr><tr><td>AL1O</td><td>Allegro</td><td>1</td><td>O</td><td>7.8</td><td>91.6</td><td>0.50</td><td>4.2</td><td>0.0</td><td>1.6</td><td>3.9</td><td>0.2</td><td>1.0</td><td>0.8</td><td>1.9</td><td>0.5</td><td>50.2</td><td>0.0</td><td>7.0</td></tr><tr><td>AL2R</td><td>Allegro</td><td>2</td><td>R</td><td>2.7</td><td>98.6</td><td>0.46</td><td>4.2</td><td>0.0</td><td>2.1</td><td>2.4</td><td>0.1</td><td>0.8</td><td>0.6</td><td>1.2</td><td>0.0</td><td>29.1</td><td>0.0</td><td>5.2</td></tr><tr><td>AL2O</td><td>Allegro</td><td>2</td><td>O</td><td>3.2</td><td>79.6</td><td>0.46</td><td>4.5</td><td>0.1</td><td>2.4</td><td>1.8</td><td>0.2</td><td>0.8</td><td>1.0</td><td>1.2</td><td>0.0</td><td>42.1</td><td>0.1</td><td>8.2</td></tr><tr><td>CL1R</td><td>Clery</td><td>1</td><td>R</td><td>8.3</td><td>123.5</td><td>0.06</td><td>5.8</td><td>0.0</td><td>0.4</td><td>3.5</td><td>0.1</td><td>0.8</td><td>0.4</td><td>0.2</td><td>0.1</td><td>29.2</td><td>0.9</td><td>8.0</td></tr><tr><td>CL1O</td><td>Clery</td><td>1</td><td>O</td><td>3.4</td><td>131.5</td><td>1.49</td><td>6.8</td><td>0.2</td><td>1.9</td><td>2.8</td><td>0.0</td><td>0.0</td><td>0.5</td><td>0.6</td><td>0.2</td><td>43.6</td><td>1.2</td><td>9.5</td></tr><tr><td>CL2R</td><td>Clery</td><td>2</td><td>R</td><td>5.4</td><td>112.6</td><td>0.14</td><td>9.2</td><td>0.0</td><td>2.8</td><td>4.7</td><td>0.1</td><td>0.8</td><td>0.4</td><td>0.8</td><td>0.2</td><td>32.0</td><td>0.8</td><td>7.9</td></tr><tr><td>CL2O</td><td>Clery</td><td>2</td><td>O</td><td>3.0</td><td>81.7</td><td>0.05</td><td>8.7</td><td>0.2</td><td>4.2</td><td>2.1</td><td>0.0</td><td>0.6</td><td>0.4</td><td>1.2</td><td>0.1</td><td>48.3</td><td>0.6</td><td>13.0</td></tr><tr><td>FA1R</td><td>Faith</td><td>1</td><td>R</td><td>7.1</td><td>93.7</td><td>0.02</td><td>4.6</td><td>0.2</td><td>1.9</td><td>2.3</td><td>0.1</td><td>0.6</td><td>0.8</td><td>0.6</td><td>0.1</td><td>35.1</td><td>1.5</td><td>19.4</td></tr><tr><td>FA1O</td><td>Faith</td><td>1</td><td>O</td><td>4.7</td><td>77.5</td><td>0.11</td><td>5.7</td><td>0.1</td><td>0.2</td><td>1.8</td><td>0.1</td><td>0.7</td><td>1.1</td><td>0.9</td><td>0.0</td><td>48.8</td><td>2.7</td><td>29.3</td></tr><tr><td>FA2R</td><td>Faith</td><td>2</td><td>R</td><td>8.3</td><td>101.1</td><td>0.11</td><td>6.3</td><td>0.2</td><td>2.9</td><td>2.9</td><td>0.2</td><td>0.9</td><td>0.7</td><td>1.0</td><td>0.8</td><td>31.9</td><td>1.3</td><td>14.7</td></tr><tr><td>FA2O</td><td>Faith</td><td>2</td><td>O</td><td>5.9</td><td>95.9</td><td>0.12</td><td>6.0</td><td>0.1</td><td>0.4</td><td>2.4</td><td>0.1</td><td>0.8</td><td>1.0</td><td>1.1</td><td>0.6</td><td>46.1</td><td>1.6</td><td>27.2</td></tr><tr><td>LX1R</td><td>Limalexia</td><td>1</td><td>R</td><td>5.6</td><td>132.9</td><td>0.04</td><td>4.6</td><td>0.1</td><td>0.0</td><td>1.6</td><td>0.0</td><td>0.1</td><td>0.1</td><td>0.3</td><td>0.0</td><td>12.9</td><td>1.0</td><td>3.6</td></tr><tr><td>LX1O</td><td>Limalexia</td><td>1</td><td>O</td><td>5.4</td><td>130.5</td><td>0.05</td><td>5.4</td><td>0.1</td><td>0.0</td><td>2.0</td><td>0.1</td><td>0.3</td><td>0.1</td><td>0.5</td><td>0.0</td><td>18.1</td><td>1.4</td><td>5.2</td></tr><tr><td>LX2R</td><td>Limalexia</td><td>2</td><td>R</td><td>7.9</td><td>89.4</td><td>0.00</td><td>6.4</td><td>0.2</td><td>0.1</td><td>2.2</td><td>0.1</td><td>0.3</td><td>0.2</td><td>0.4</td><td>0.1</td><td>15.7</td><td>1.0</td><td>5.1</td></tr><tr><td>LX2O</td><td>Limalexia</td><td>2</td><td>O</td><td>7.4</td><td>109.7</td><td>0.00</td><td>8.5</td><td>0.2</td><td>0.2</td><td>1.9</td><td>0.1</td><td>0.4</td><td>0.3</td><td>0.9</td><td>0.0</td><td>30.8</td><td>2.1</td><td>10.1</td></tr><tr><td>MC1R</td><td>MallingCentenary</td><td>1</td><td>R</td><td>7.0</td><td>89.2</td><td>0.02</td><td>2.2</td><td>0.0</td><td>0.9</td><td>3.3</td><td>0.0</td><td>0.5</td><td>0.3</td><td>0.7</td><td>0.2</td><td>16.1</td><td>0.6</td><td>5.4</td></tr><tr><td>MC1O</td><td>MallingCentenary</td><td>1</td><td>O</td><td>4.8</td><td>96.6</td><td>0.21</td><td>3.4</td><td>0.0</td><td>0.9</td><td>1.7</td><td>0.1</td><td>0.7</td><td>0.3</td><td>1.0</td><td>0.4</td><td>29.0</td><td>0.8</td><td>5.8</td></tr><tr><td>MC2R</td><td>MallingCentenary</td><td>2</td><td>R</td><td>1.8</td><td>108.4</td><td>0.15</td><td>6.7</td><td>0.1</td><td>1.3</td><td>2.5</td><td>0.1</td><td>0.5</td><td>0.6</td><td>0.5</td><td>0.0</td><td>23.3</td><td>1.4</td><td>12.4</td></tr><tr><td>MC2O</td><td>MallingCentenary</td><td>2</td><td>O</td><td>3.3</td><td>79.5</td><td>0.00</td><td>7.5</td><td>0.0</td><td>1.6</td><td>2.1</td><td>0.1</td><td>0.5</td><td>1.1</td><td>0.8</td><td>0.0</td><td>36.1</td><td>2.6</td><td>7.4</td></tr><tr><td>RI1R</td><td>1503 Ritmo</td><td>1</td><td>R</td><td>5.8</td><td>120.6</td><td>0.04</td><td>2.4</td><td>0.1</td><td>0.1</td><td>5.2</td><td>0.0</td><td>0.4</td><td>0.2</td><td>0.3</td><td>0.0</td><td>13.2</td><td>1.1</td><td>3.1</td></tr><tr><td>RI01</td><td>1503 Ritmo</td><td>1</td><td>O</td><td>5.0</td><td>104.1</td><td>0.04</td><td>3.5</td><td>0.1</td><td>0.1</td><td>3.7</td><td>0.1</td><td>0.5</td><td>0.3</td><td>0.3</td><td>0.1</td><td>21.0</td><td>1.7</td><td>5.6</td></tr><tr><td>RIR2</td><td>1503 Ritmo</td><td>2</td><td>R</td><td>10.5</td><td>92.7</td><td>0.00</td><td>7.6</td><td>0.2</td><td>0.5</td><td>1.6</td><td>0.1</td><td>0.4</td><td>0.1</td><td>0.6</td><td>0.1</td><td>18.6</td><td>1.3</td><td>6.1</td></tr><tr><td>RI02</td><td>1503 Ritmo</td><td>2</td><td>O</td><td>7.6</td><td>120.0</td><td>0.00</td><td>6.6</td><td>0.3</td><td>1.7</td><td>4.2</td><td>0.2</td><td>0.8</td><td>0.8</td><td>0.6</td><td>0.0</td><td>44.9</td><td>2.5</td><td>14.7</td></tr><tr><td>RVR1</td><td>Rendezvous</td><td>1</td><td>R</td><td>7.6</td><td>91.2</td><td>0.00</td><td>3.3</td><td>0.0</td><td>1.2</td><td>2.2</td><td>0.1</td><td>0.3</td><td>0.2</td><td>1.2</td><td>0.4</td><td>20.5</td><td>1.2</td><td>6.2</td></tr><tr><td>RVO1</td><td>Rendezvous</td><td>1</td><td>O</td><td>8.6</td><td>92.1</td><td>0.02</td><td>5.2</td><td>0.0</td><td>1.5</td><td>1.7</td><td>0.2</td><td>0.3</td><td>0.4</td><td>1.6</td><td>0.6</td><td>32.3</td><td>1.9</td><td>9.4</td></tr><tr><td>RV2R</td><td>Rendezvous</td><td>2</td><td>R</td><td>8.8</td><td>82.9</td><td>0.02</td><td>4.7</td><td>0.1</td><td>0.9</td><td>0.9</td><td>0.0</td><td>0.3</td><td>0.3</td><td>1.4</td><td>0.0</td><td>32.1</td><td>1.9</td><td>10.7</td></tr><tr><td>RV2O</td><td>Rendezvous</td><td>2</td><td>O</td><td>7.0</td><td>76.9</td><td>0.07</td><td>8.8</td><td>0.1</td><td>2.7</td><td>1.5</td><td>0.0</td><td>0.4</td><td>0.5</td><td>2.0</td><td>1.3</td><td>45.7</td><td>3.7</td><td>17.3</td></tr><tr><td>SI1R</td><td>Sibila</td><td>1</td><td>R</td><td>8.2</td><td>111.2</td><td>0.04</td><td>5.2</td><td>0.0</td><td>1.7</td><td>4.8</td><td>0.2</td><td>0.4</td><td>0.2</td><td>1.3</td><td>0.3</td><td>21.6</td><td>1.5</td><td>4.0</td></tr><tr><td>SI1O</td><td>Sibila</td><td>1</td><td>O</td><td>8.1</td><td>118.2</td><td>0.00</td><td>5.3</td><td>0.0</td><td>1.7</td><td>4.0</td><td>0.2</td><td>0.2</td><td>0.2</td><td>0.6</td><td>0.1</td><td>26.1</td><td>0.6</td><td>1.6</td></tr><tr><td>SI2R</td><td>Sibila</td><td>2</td><td>R</td><td>11.0</td><td>151.2</td><td>0.03</td><td>8.6</td><td>0.3</td><td>1.9</td><td>2.5</td><td>0.1</td><td>0.5</td><td>0.2</td><td>1.9</td><td>0.5</td><td>27.4</td><td>2.2</td><td>4.5</td></tr><tr><td>SI2O</td><td>Sibila</td><td>2</td><td>O</td><td>8.6</td><td>129.3</td><td>0.06</td><td>8.3</td><td>0.2</td><td>2.4</td><td>2.4</td><td>0.1</td><td>0.5</td><td>0.3</td><td>2.2</td><td>0.5</td><td>34.9</td><td>2.5</td><td>2.0</td></tr><tr><td></td><td>Pooled SD</td><td></td><td></td><td>0.5</td><td>5.9</td><td>0.0</td><td>0.4</td><td>0.0</td><td>1.5</td><td>0.4</td><td>0.0</td><td>0.1</td><td>0.1</td><td>0.2</td><td>0.1</td><td>1.9</td><td>0.2</td><td>1.4</td></tr></tbody></table><table><caption>Statistics: F-value and significance</caption><tbody><tr><td>Cultivar</td><td>30***</td><td>15***</td><td>20***</td><td>30***</td><td>9***</td><td>1</td><td>10***</td><td>21***</td><td>19***</td><td>45***</td><td>27***</td><td>16***</td><td>46***</td><td>32***</td><td>59***</td></tr><tr><td>Harvest time</td><td>1</td><td>3</td><td>10**</td><td>297***</td><td>7**</td><td>9**</td><td>11**</td><td>5*</td><td>13***</td><td>32***</td><td>28***</td><td>3</td><td>52***</td><td>32***</td><td>21***</td></tr><tr><td>Ripening stage</td><td>38***</td><td>2</td><td>8**</td><td>34***</td><td>5*</td><td>1</td><td>3</td><td>19***</td><td>0</td><td>67***</td><td>20***</td><td>6*</td><td>271***</td><td>42***</td><td>37***</td></tr><tr><td>Cultivar*Ripening Stage</td><td>28***</td><td>6***</td><td>7***</td><td>8***</td><td>32**</td><td>4**</td><td>4**</td><td>15***</td><td>3**</td><td>6***</td><td>6***</td><td>11***</td><td>9***</td><td>11***</td><td>4***</td></tr><tr><td>Cultivar*Harvest</td><td>6***</td><td>1</td><td>7***</td><td>5***</td><td>24***</td><td>0</td><td>3*</td><td>3*</td><td>5***</td><td>4**</td><td>2</td><td>9***</td><td>3*</td><td>5***</td><td>8***</td></tr><tr><td>Harvest*Ripening Stage</td><td>0</td><td>2</td><td>12***</td><td>2</td><td>0</td><td>0</td><td>1</td><td>6*</td><td>2</td><td>7*</td><td>0</td><td>0</td><td>5*</td><td>6*</td><td>2</td></tr></tbody></table>

Harv: harvest time; Rip: ripening stage. R: Ripe; O: Overripe. CAT: (+)-catechin. PACs: Proanthocyanidins. MEadhex: Methylellagic acid deoxyhexoside. pCoumHex: p-Coumaroylhexose. DHFHex: Dihydroferulic acid hexoside. CAH: Caffeic acid hexoside. Q3GlcU: Quercetin-3-O-glucuronide. Kpf3CoumHex: Kaempferol-3-O-coumaroylhexoside. Kpf3GlcU: Kaempferol-3-O-glucuronide. Kpf3MalGlc: Kaempferol-3-O-malonylglucoside. Cy3Glc: Cyanidin-3-O-glucoside. Cy3MalGlc: Cyanidin-3-O-malonylglucoside. Plg3Glc: Pelargonidin-3-O-glucoside. Plg3Rut: Pelargonidin-3-O-rutinoside. Plg3MalGlc: Pelargonidin-3-O-malonylglucoside. Pooled SD: pooled standard deviation (degree of freedom: 64). Fisher's value. *p* ≤ 0.05: **. *p* ≤ 0.01: **. *p* ≤ 0.001: ***.
<caption>**Table 5**</caption>

Mean degree of polymerisation (mDP) and proportion of constitutive units (%) of strawberry proanthocyanidins after furanolysis.

<table><thead><tr><th>Code</th><th>Cultivar</th><th>Harvest time</th><th>Ripening stage</th><th>mDP</th><th>Terminal unit</th><th>Extension unit</th><th></th><th></th></tr></thead><tbody><tr><td>AL1R</td><td>Allegro</td><td>1</td><td>R</td><td>10.9</td><td>9.7</td><td>23.9</td><td>58.2</td><td>8.1</td></tr><tr><td>AL10</td><td>Allegro</td><td>1</td><td>O</td><td>10.2</td><td>9.8</td><td>23.6</td><td>55.3</td><td>11.3</td></tr><tr><td>AL2R</td><td>Allegro</td><td>2</td><td>R</td><td>7.0</td><td>14.3</td><td>15.9</td><td>59.7</td><td>10.1</td></tr><tr><td>AL20</td><td>Allegro</td><td>2</td><td>O</td><td>9.0</td><td>11.1</td><td>15.8</td><td>59.6</td><td>13.5</td></tr><tr><td>CL1R</td><td>Clery</td><td>1</td><td>R</td><td>7.4</td><td>13.5</td><td>26.5</td><td>54.4</td><td>5.6</td></tr><tr><td>CL10</td><td>Clery</td><td>1</td><td>O</td><td>6.1</td><td>16.5</td><td>25.6</td><td>51.1</td><td>6.8</td></tr><tr><td>CL2R</td><td>Clery</td><td>2</td><td>R</td><td>7.9</td><td>12.8</td><td>20.4</td><td>59.4</td><td>7.4</td></tr><tr><td>CL20</td><td>Clery</td><td>2</td><td>O</td><td>7.4</td><td>13.6</td><td>20.1</td><td>57.7</td><td>8.7</td></tr><tr><td>FA1R</td><td>Faith</td><td>1</td><td>R</td><td>11.0</td><td>9.1</td><td>12.4</td><td>72.3</td><td>6.2</td></tr><tr><td>FA10</td><td>Faith</td><td>1</td><td>O</td><td>12.3</td><td>8.2</td><td>11.6</td><td>70.7</td><td>9.6</td></tr><tr><td>FA2R</td><td>Faith</td><td>2</td><td>R</td><td>11.7</td><td>8.6</td><td>12.4</td><td>74.2</td><td>4.9</td></tr><tr><td>FA20</td><td>Faith</td><td>2</td><td>O</td><td>11.7</td><td>8.5</td><td>11.8</td><td>72.5</td><td>7.2</td></tr><tr><td>LX1R</td><td>Limalexia</td><td>1</td><td>R</td><td>7.6</td><td>13.5</td><td>23.1</td><td>58.9</td><td>4.5</td></tr><tr><td>LX10</td><td>Limalexia</td><td>1</td><td>O</td><td>7.9</td><td>13.0</td><td>24.0</td><td>58.0</td><td>5.0</td></tr><tr><td>LX2R</td><td>Limalexia</td><td>2</td><td>R</td><td>8.9</td><td>11.8</td><td>23.3</td><td>58.5</td><td>6.3</td></tr><tr><td>LX20</td><td>Limalexia</td><td>2</td><td>O</td><td>9.4</td><td>10.7</td><td>19.4</td><td>62.5</td><td>7.4</td></tr><tr><td>MC1R</td><td>Malling Centenary</td><td>1</td><td>R</td><td>7.7</td><td>13.0</td><td>26.2</td><td>54.8</td><td>6.1</td></tr><tr><td>MC10</td><td>Malling Centenary</td><td>1</td><td>O</td><td>7.5</td><td>13.3</td><td>24.0</td><td>52.6</td><td>10.0</td></tr><tr><td>MC2R</td><td>Malling Centenary</td><td>2</td><td>R</td><td>10.0</td><td>10.0</td><td>18.6</td><td>62.6</td><td>8.8</td></tr><tr><td>MC20</td><td>Malling Centenary</td><td>2</td><td>O</td><td>6.5</td><td>15.3</td><td>16.6</td><td>53.8</td><td>14.3</td></tr><tr><td>RI1R</td><td>1503 Ritmo</td><td>1</td><td>R</td><td>7.1</td><td>14.5</td><td>25.1</td><td>57.0</td><td>3.5</td></tr><tr><td>RI01</td><td>1503 Ritmo</td><td>1</td><td>O</td><td>6.7</td><td>15.0</td><td>25.7</td><td>53.2</td><td>6.0</td></tr><tr><td>RIR2</td><td>1503 Ritmo</td><td>2</td><td>R</td><td>11.2</td><td>9.7</td><td>24.5</td><td>60.5</td><td>5.4</td></tr><tr><td>RI02</td><td>1503 Ritmo</td><td>2</td><td>O</td><td>10.0</td><td>10.0</td><td>20.4</td><td>62.9</td><td>6.7</td></tr><tr><td>RVR1</td><td>Rendezvous</td><td>1</td><td>R</td><td>6.6</td><td>15.1</td><td>31.8</td><td>46.3</td><td>6.8</td></tr><tr><td>RVO1</td><td>Rendezvous</td><td>1</td><td>O</td><td>7.8</td><td>12.9</td><td>32.8</td><td>45.7</td><td>8.6</td></tr><tr><td>RV2R</td><td>Rendezvous</td><td>2</td><td>R</td><td>10.1</td><td>10.5</td><td>26.5</td><td>55.1</td><td>7.9</td></tr><tr><td>RV20</td><td>Rendezvous</td><td>2</td><td>O</td><td>11.5</td><td>9.0</td><td>24.3</td><td>56.1</td><td>10.6</td></tr><tr><td>SI1R</td><td>Sibila</td><td>1</td><td>R</td><td>7.1</td><td>14.1</td><td>26.0</td><td>53.2</td><td>6.7</td></tr><tr><td>SI10</td><td>Sibila</td><td>1</td><td>O</td><td>6.8</td><td>14.8</td><td>25.5</td><td>52.2</td><td>7.5</td></tr><tr><td>SI2R</td><td>Sibila</td><td>2</td><td>R</td><td>8.4</td><td>11.9</td><td>18.2</td><td>61.6</td><td>8.3</td></tr><tr><td>SI20</td><td>Sibila</td><td>2</td><td>O</td><td>8.4</td><td>11.9</td><td>17.8</td><td>61.4</td><td>8.8</td></tr><tr><td></td><td></td><td></td><td>Pooled SD</td><td>1.0</td><td>0.9</td><td>1.1</td><td>1.9</td><td>0.3</td></tr></tbody></table><table><caption>Statistics: F-value and significance</caption><tbody><tr><td>Cultivar</td><td>10***</td><td>12***</td><td>59***</td><td>34***</td><td>110***</td></tr><tr><td>Harvest time</td><td>8**</td><td>20***</td><td>146***</td><td>49***</td><td>145***</td></tr><tr><td>Ripening stage</td><td>0</td><td>0</td><td>4*</td><td>3</td><td>311***</td></tr><tr><td>Cultivar*Ripening Stage</td><td>7***</td><td>8***</td><td>7***</td><td>2</td><td>19***</td></tr><tr><td>Cultivar*Harvest</td><td>2</td><td>3**</td><td>0</td><td>1</td><td>15***</td></tr><tr><td>Harvest*Ripening Stage</td><td>1</td><td>0</td><td>4</td><td>1</td><td>0</td></tr></tbody></table>

R: Ripe; O: Overripe. Fisher's value. $p \le 0.05$; *. $p \le 0.01$; **. $p \le 0.001$; ***. Pooled SD: pooled standard deviation (degree of freedom: 64).

malonylglucoside depended on each cultivar (Aaby et al., 2012; Buendía et al., 2010).

The study of the flavonoid biosynthetic pathway in strawberries has shown that expression patterns of flavonoid genes are actually cultivar-dependent (Lee et al., 2022). Thus, the genetic differences among the cultivars are largely responsible for the difference in polyphenol profile and content.

### 3.3.2. Ripening effect on polyphenols

The influence of the ripening stage was significant for most phenolic compounds, mainly for anthocyanins and (+)-catechin ($p \le 0.0001$), except for proanthocyanidins, caffeic acid hexoside, quercetin-3-O-glucuronide and kaempferol-3-O-glucuronide. Total phenolic compounds increased along ripening for most cultivars, mainly because of the increase in anthocyanins (Table 4). Other studies observed a decrease in total polyphenols during ripening, possibly attributed to the analysis of other ripening stages not included in this work (green stage) (Lee et al., 2022; Nunes et al., 2006; Ornelas-Paz et al., 2013; Parra-Palma et al., 2020) and to extraction method used (Määttä-Riihinen et al., 2004).

Anthocyanin contents increased with ripening in agreement with previous work (Almeida et al., 2007; Carbone et al., 2009; Parra-Palma et al., 2020). There was a significant effect on all pelargonidin derivatives and the most significant changes were observed with

pelargonidin-3-O-β-glucoside and its malonylglucoside derivative. This effect could be explained by the late biosynthesis of anthocyanins in strawberries, which is marked only after an advanced ripening stage (i.e. overripe) (Almeida et al., 2007; Halbwirth et al., 2006).

The absence of impact of ripening on the PACs content may be due to the advanced ripening stage in this study (juice quality fruits), where PACs synthesis is less active than in early (green) stages. The ripening stage however had a large effect on epiafzelechin ($p \le 0.001$) and a slighter effect on (+)-catechin, ($p \le 0.05$), both as extension units (Table 5). The (+)-catechin content slightly decreased with ripening, with the most significant change occurring in cultivar 'Clery'. Epiafzelechin increased in all cultivars, especially in cultivars 'Allegro' and 'Malling Centenary'. The effect of ripening stage on total flavonols was not significant, as changes were not uniform among cultivars. However, statistically different increases were observed in contents of kaempferol-3-O-p-coumaroylglucoside and kaempferol-3-O-malonylglucoside. The behaviour of phenolic acid derivatives in response to ripening was similar, with significant effects mainly for p-coumaroyl hexose.

### 3.3.3. Harvest time effect on polyphenols

The effect of harvest time was significant ($p \le 0.001$) for anthocyanins and phenolic acid derivatives (Table 4). Anthocyanins increased significantly with late harvest of strawberries, except in the case of 'Faith' and 'Allegro' cultivars, probably due to a very advanced ripening
stage. Phenolic acid derivatives increased significantly with harvest time in all cultivars. The effect was stronger (p ≤ 0.0001) on p-coumaroyl hexose. Changes in PACs were considerable but depended on cultivar. However, the PACs mDP increased with harvest time, while (+)-catechin decreased (both as extension and terminal units), with different extent depending on cultivar (Table 5). Similar results have been observed comparing strawberries from two different harvests in Italy, where the effect of environment was highly significant for the epi-catechin/catechin content (Carbone et al., 2009). Moreover, the effect on mDP was significant only in the early stages (green) of ripening, which suggests a possible interaction between ripening and harvest conditions. Regarding flavonols, changes on individual components were statistically significant (p ≤ 0.001) but not considerable. The increase in flavonoids, mainly anthocyanins, is congruent with previous results, where a difference in temperature and sunlight exposition were reported as enhancing factors on polyphenol content and flavonoid biosynthesis in strawberries (Zhang et al., 2018).

### 3.4. Nectar colour stability and correlations with polyphenols and polysaccharides

Nectars obtained after pilot-scale processing of strawberries were classified in four different groups depending on their colour change after 12 weeks storage according to AD12 values (Murray et al., 2023). A set of 40 different variables was obtained from the quantification of polyphenols and polysaccharides in strawberries, and the effect of cultivar, ripening stage and harvest time was assessed towards AD12. Significant effects from cultivar, ripening stage and harvest time were observed (p ≤ 0.0001). Distinctively, overripe samples from the late harvest showed a higher colour stability. However, colour stability was not dependent on the initial colour, as seen in 'RV20', which showed the highest stability (lowest AD12) despite a low AF0 (Table 1).

Principal Component Analysis (PCA) after statistical discriminations was used to visualize the influence and the potential role of both phenolic compound and polysaccharide contents and compositions in fruit over the colour stability during storage of strawberry nectar, i.e.,

the product obtained after pilot-scale processing (Table 1), taking into consideration, cultivar, ripening stage and harvest time. Among the 39 different variables analysed, only the 14 that were correlated with colour stability (p ≤ 0.05) were used for the PCA analysis.

The first two axes (PC1 and PC2) accounted for 51 % of the total variance, with PC1 and PC2 explaining 31.6 % and 18.9 % of the total variance, respectively (Fig. 2 A). Colour stability was mainly explained along PC1 as observed in AD12 displayed along the negative side of PC1 (Fig. 2A). The first PC-score (PC1) had a high contribution of epi-afzelechin as proanthocyanidin extension unit, pelargonidin-3-O-glucoside, and to a lesser extended by cyanidin-3-O-glucoside in the positive direction, which correlated with nectar colour stability after storage. On the opposite side, the arabinose/galactose molar ratio and PACs, and in a minor way quercetin-3-O-glucuronide, showed a negative effect on nectar stability after storage. The second PC-score had a high contribution of fucose, xylose and galactose, in the positive direction and kaempferol-3-O-malonylglucoside and pelargonidin-3-O-malonylglucoside in the opposite negative direction (Fig. 2 A). The third PC-score (PC3) also had a contribution of dry matter and AIS (supplementary material S1 and S2).

The different stability group appeared in different zone of the sample map (Fig. 2B). The stability group SG1, i.e., the most stable nectars (blue dots, Fig. 2B), was clearly discriminated from SG4 (red dots, Fig. 2B), i. e., the least stable nectars. This might suggest that differences in both polyphenols and polysaccharides contents and compositions in strawberries may influence colour stability in nectars after storage (Table 1). PC1 opposed cultivars such as “Faith”, “Allegro” and “Rendezvous” in the positive part from cultivars such as “Limalexia” and “1503 Ritmo” in the negative part. “Faith” and “Allegro” cultivars position was explained by their high contents in pelargonidin-3-O-malonylglucoside, kaempferol-3-O-malonylglucoside, and pelargonidin-3-O-glucoside for “Faith” cultivar and their low arabinose to galactose ratio and their low content in dry matter. “Rendezvous” cultivar position was explained by its high contents in cyanidin-3-O-glucoside, galactose, fucose, xylose, and (epi) afzelechin as extension unit and its low contents in AIS, proanthocyanidins, quercetin-3-O-glucuronide and its low arabinose to galactose

<figure><img src="image_4.png" /><figcaption>**Fig. 2.** Plots of Principal Component Analysis representing the variability of strawberry nectar based on both the composition in phenolic compounds and polysaccharides and colour characteristics using the first two principal components as coordinate axes. A: Correlation circle of phenolic compound and polysaccharide loadings on PC1 and PC2, B: Sample map of scores on PC1 and PC2 depending on the cultivar, ripening stage, and harvest time.</figcaption></figure>

AL: Allegro, CL: Clery, FA: Faith, LX: Limalexia, MC: Malling Centenary, RI: 1503 Ritmo, RV: Rendezvous, SI: Sibila, AIS: Alcohol Insoluble Solid, Fuc: fucose, Xyl: xylose, Gal: galactose, Glc: glucose, Ara/Gal is a ratio characteristic for the proportion of arabinose vs galactose in rhamnogalacturonan-I, PACs: Proanthocyanidins, Q3GlcU: Quercetin-3-O-glucuronide, Kpf3MalGlc: Kaempferol-3-O-malonylglucoside, Cy3Glc: Cyanidin-3-O-glucoside, Plg3Glc: Pelargonidin-3-O-glucoside, Plg3MalGlc: Pelargonidin-3-O-malonylglucoside, AD12: the difference in AF between the day of production and week 12 of storage (AD12), respectively. Samples were divided in 4 groups (1–4) according to AD12, with group 1 being the most stable samples and 4 the least stable samples (Table 1).

<figure><img src="image_5.png" /></figure>
ratio. "Limalexia" and "1503 Ritmo" cultivars position was explained by their high arabinose to galactose ratio, and their high contents in proanthocyanidins, quercetin-3-O-glucuronide and AIS and their low contents in pelargonidin-3-O-glucoside, cyanidin-3-O-glucoside, kaempferol-3-O-malonylglucoside, (epi)afzelechin as extension unit, galactose, pelargonidin-3-O-malonylglucoside, fucose and xylose. PC2 opposed "Rendezvous" and "Allegro" cultivars in the positive part from "Faith" cultivar in the negative part. "Rendezvous" and "Allegro" cultivars position was explained by their high contents in cyanidin-3-O-glucoside, galactose, fucose, xylose and (epi)afzelechin as extension unit and to their low contents in AIS, proanthocyanidins, quercetin-3-O-glucuronide and their low arabinose to galactose ratio. "Faith" position was explained by its high content in pelargonidin-3-O-malonylglucoside, kaempferol-3-O-malonylglucoside and pelargonidin-3-O-glucoside and its low arabinose to galactose ratio and its low content in dry matter. According to PCA result, colour stability in strawberry nectar during storage could be promoted by the presence of pelargonidin-3-O-glucoside and cyanidin-3-O-glucoside, high percentage of (epi)afzelechin in proanthocyanidins and pectin with galactose side chains. The presence of pelargonidin-3-O-glucoside in high stable samples probably simply reflects its role as the main pigment in strawberry, followed by a minor contribution of cyanidin-3-O-glucoside and pelargonidin-3-O-malonylglucoside. Nevertheless, samples from cultivar "Rendezvous" and "Allegro" displayed high colour stability despite the lower anthocyanin content. Likewise, their high content in pelargonidin-3-O-malonylglucoside, low content in AIS, PACs and pectin with galactose side chains over arabinose might have contributed to nectar colour stability.

The influence of anthocyanin content and composition was anticipated, although it did not completely explain colour stability. Moreover, the influence of PACs content and composition as well as that of pectin composition were unexpected findings. In particular, the effect of polysaccharides on nectar colour stability, as polysaccharides are not associated directly with colour perception. The colour of anthocyanins can be stabilized by π-stacking interactions with polyphenols (Trouillas et al., 2016) but also by hydrophobic and electrostatic interactions with polysaccharides (Buchweitz et al., 2013). Hence, competitive interactions of polyphenols and polysaccharides with anthocyanins may lead to an overall effect on colour. Three phenomena may explain the influence of pectin composition as well as that of proanthocyanidins on nectar colour stability after pilot-scale processing as observed on PCA (Fig. 2 A and B).

Firstly, polysaccharides may interact with anthocyanins, depending on their structure. In a previous study with strawberry anthocyanin extracts, addition of apple or sugar beet pectin improved anthocyanin retention up to 20 % compared with the presence of citrus pectins, suggesting an influence of pectin nature and composition (Buchweitz et al., 2013). Moreover, our results seemed to suggest that high arabinose/galactose ratio of pectin side chains were correlated with lower colour stability (Fig. 2A). This could mean that a rhamnogalacturonic backbone with side chains mainly composed of galactan instead of arabinan may display a higher affinity for anthocyanins, via the establishment of hydrogen bonds and electrostatic interactions with the carboxylic/carboxylate and hydroxyl groups of pectins. This could improve thus anthocyanin stability. Furthermore, Watrelot et al. (Watrelot et al., 2014) showed that arabinan-rich pectin side chains, i.e. with a high arabinose/galactose ratio, have a low affinity for procyranidins, which also depends on their branching degree, linear arabinans having a higher affinity for proanthocyanidins than branched arabinans (Fernandes et al., 2020). Hence, galactan-rich pectins may protect the flavylium cation from the nucleophilic attack of water with concomitant colour loss (Buchweitz et al., 2012; Fernandes et al., 2014). In grape to wine model, polysaccharides rich in arabinose and galactose are involved in anthocyanins and proanthocyanidins extraction (Boulet et al., 2024), with a higher anthocyanin extractability, i.e., lower cell wall anthocyanin interactions, with a higher percentage of arabinose (Boulet et al., 2023).

Secondly, the pectin matrix could also limit the contact between transition metal ions and anthocyanins susceptible to initiate their autoxidation (Dangles, 2024). However due to the pectin DM variability of our data set, from 46 % (FA2R) to 83.1 % (LX1R) with a mean DM of 60 %, the effect of pectin DM on colour stability was not established.

Thirdly, polysaccharides are known to interact also with PACs and both structures have a strong influence on the binding strength. Especially, the hydroxylation pattern of PACs, i.e., from propelargonidins to procyanidins and finally to prodelphinidins, increases their ability to bind polysaccharides (Le Bourvellec & Renard, 2012). Hence, a lower hydroxylation pattern due to a higher epiafzelechin content may limit interactions between PACs and pectins, thus favouring interactions between anthocyanins and pectins and allowing a higher colour stability.

On the other hand, PACs, the main group of phenolic compounds in strawberry, may have contrasted effects on anthocyanin stability (Dangles & Fenger, 2018). They can act as moderate copigments, thus limiting water addition to the flavylium ion (reversible formation of a colourless hemiketal) by π-stacking interactions. By contrast, through their nucleophilic A-ring, they can react with the flavylium ion to form colourless adducts. Moreover, the inter-flavanol bonds of PACs are also vulnerable to acidolysis with release of carbocations susceptible to react with anthocyanins (through the nucleophilic hemiketal), as evidenced by the detection of pigment 1 A in nectar (Table 3).

## 4. Conclusions

The main results showed a high influence of cultivar in the contents in both phenolic compounds and polysaccharides in strawberry. The effects of ripening stage and harvest date were cultivar-dependent but in general anthocyanins increased with ripening and late harvest while proanthocyanidins, the main phenolic class in strawberry, decreased. For polysaccharides, the decrease in neutral sugars, mainly arabinose and galactose, was the main change observed with both ripening stage and harvest time. Our study seemed to reveal that the colour stability of strawberry nectars during storage is influenced by a complex interplay of phenolic compounds and polysaccharides. Significant effects of cultivar, ripening stage, and harvest time on colour stability were observed. Notably, overripe samples from the late harvest showed higher colour stability, independent of initial colour. Principal Component Analysis (PCA) highlighted the contribution of specific compounds. Total PACs, rather than acting as copigments, seemed to have a negative effect towards colour stability in strawberry nectar after 12 weeks of storage, whereas epiafzelechin in proanthocyanidins correlated with high colour stability in nectars. Unexpectedly, polysaccharides could also play a significant role in colour stability. Pectin may interact competitively with anthocyanins and proanthocyanidins leading thus to an overall change of colour. PCA results could suggest that pectin with side chains with a lower arabinose/galactose ratio may enhance anthocyanin stability. This work highlights that predicting the nectar's colour stability from the strawberry remains a challenge as for wine from grape and cider from apple. However, our dataset had some limitations. No cultivars dedicated to processing were analysed as is the case, for example, with cider, perry or wine, which are made from specific varieties. No analysis of both the phenolic compound and polysaccharide contents and compositions of the nectars after 12 weeks' storage were done. Only native phenolic compounds were quantified whereas during cell disruption phenolic compounds such as proanthocyanidins and anthocyanins evolved as a result of chemical modifications leading to the formation of adducts, e.g., process-induced molecules such as pigment 1 A (Table 3), which could influence nectar's colour and nectar colour's stability. This finding may introduce a bias in our analysis of the colour stability of nectar after processing and the unexpected result regarding the influence of proanthocyanidin content and composition as well as that of pectin side chains on colour stability. Hence, the question of the nectar's colour stability is far from simple and need more experiments to understand the relationship between the key
parameters, i.e., anthocyanins, proanthocyanidins and pectins, and the mechanisms involved towards colour stability.

Structural information on the cell wall network (porosity, accessi-
bility to binding sites, interactions between polysaccharides) and its
changes depending on cultivar, ripening and harvest date, along with a
better understanding on its interactions with anthocyanins and proan-
thocyanidins, is need to better relate strawberry and nectar colour sta-
bility. Moreover, changes in phenolic compounds and cell walls in
strawberries should be further studied after processing and during
storage, including parameters that can further influence the long-term
stability (pH, vitamin C, iron content, etc). Currently, additional work
is in progress to assess the effect of PACs and pectin extracts on the
stability of strawberry anthocyanins in a model system, this will allow to
investigate the role of pectin-anthocyanin interactions, anthocyanin-
proanthocyanidin interactions and competition between anthocyanins
and proanthocyanidins for the pectin binding sites on colour stability.
These investigations could help to elucidate the role of these macro-
molecules in the colour stability of fruit products and to predict the
ability of strawberry to give nectar which colour will be more or less
stable.

CRediT authorship contribution statement

**S. Rincon:** Writing – original draft, Investigation, Formal analysis, Data curation. **H. Murray:** Writing – review & editing, Formal analysis, Data curation. **M. Gössinger:** Writing – review & editing, Supervision, Project administration, Funding acquisition, Conceptualization. **C. Ginies:** Writing – review & editing, Investigation, Data curation. **P. Goupy:** Writing – review & editing, Formal analysis, Data curation. **C. Dufour:** Writing – review & editing, Supervision, Formal analysis, Data curation, Conceptualization. **O. Dangles:** Writing – review & editing, Supervision, Formal analysis, Data curation, Conceptualization. **C. Le Bourvellec:** Writing – review & editing, Validation, Supervision, Project administration, Funding acquisition, Formal analysis, Data curation, Conceptualization.

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgements

This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 956257. Thanks to Line Touloumet, Caroline Garcia, and Marielle Boge (INRAE, UMR408 SQPOV) for their technical help.

**Appendix A. Supplementary data**

Supplementary data to this article can be found online at https://doi.
org/10.1016/j.foodchem.2025.143112.

Data availability

Data will be made available on request.

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