# Impact of salt and fat reduction under low pressure mixing on pizza dough properties

Nair Nikhil Haridasan, Nasser Hamdami, Klaus Lösche, Alain Le-Bail

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Nair Nikhil Haridasan, Nasser Hamdami, Klaus Lösche, Alain Le-Bail. Impact of salt and fat reduction under low pressure mixing on pizza dough properties. LWT - Food Science and Technology, 2025, 217, pp.117410. 10.1016/j.lwt.2025.117410. hal-05366279

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# Impact of salt and fat reduction under low pressure mixing on pizza dough properties

Nair Nikhil Haridasan<sup>a</sup>, Nasser Hamdami<sup>a, *</sup>, Klaus Lösche<sup>b</sup>, Alain Le-Bail<sup>a</sup>

## ARTICLE INFO

**Keywords:**

Pizza

Dough

Mixing

Salt and fat reduction

Viscoelastic properties

Torque analysis

## ABSTRACT

The increasing concern over the health implications of high salt and fat content in baked products has prompted a focus on optimizing their production processes. This work studied the impact of different levels of salt and fat on the energy parameters including dough development time, specific mechanical energy, and average power consumption during mixing. The gauge pressure of mixing allows controlling the gluten network formation. Hence, a Box-Behnken model was used to design the experiments for different levels of fat, salt and gauge pressure during mixing. Various dependent variables were measured, including void fraction, sheeting torque, extensibility and stickiness. The sheeted pizza doughs were baked, and changes in diameter after baking were analyzed using image analysis. The results showed that dough development time during mixing increased with salt content, while specific mechanical energy and average power consumption decreased with increasing fat content. The highest value of dough void fraction observed at atmospheric pressure. Sheeting torque was significantly affected by fat content at lower roller intervals. Resistance to extension increased with salt content, while the stickiness of the dough was influenced by both fat content and pressure. Deformation during baking increased with fat content.

## 1. Introduction

The inclusion of fat and salt as ingredients in many baked products has proven interest for the rheology and sensorial attributes of the final product. However, the increased quantity of these ingredients in recipes poses health concerns, particularly in industrialized countries. The recommended daily salt intake for maintaining bodily functions is around 1.5 g/day (Ferrari et al., 2022; Ruston et al., 2004). Given the associated risks of high blood pressure and cardiovascular diseases due to elevated sodium intake, it is under serious observation by the European Authorities. Along with salt, hypercholesterolemia, an important risk factor for cardiovascular diseases resulting from high fat intake is also a main cause of the mortality in these countries (Quilez et al., 2003; Santos et al., 2023). Innovative strategies that alter salt structure and distribution in food products can enhance saltiness perception and promote healthier options (Sun et al., 2021). Monterio et al. (2021) showed that integrating waxy starch-based salt agglomerates into bread maintained quality while achieving a 30% reduction in salt content. Crucean et al. (2023) found that replacing sodium chloride with choline chloride in bread resulted in a softer crumb, slower staling, and similar

technological properties compared to traditional bread. Reducing salt intake necessitates changes in both commercial food production and consumer behavior (Zandstra et al., 2016). Hence, there's a need for research in baking to explore methods of reducing salt and fat content while preserving the sensorial and rheological attributes necessary for producing nutritionally stable baked product. Dough is a homogeneous mixture of starch, protein, fat, salt, yeast, and other components (Song & Zheng, 2007), each playing a major role in providing a visco-elastic nature to the dough. Dough mixing stands as one of the most important unit operations in the bread-making process. According to Bloksma et al. (1988), factors such as specific mechanical energy (SME), average power consumption (APC) and mixing time, which vary among different wheat varieties and used mixers, significantly influence the optimal development of dough structure. Industrial dough mixing often occurs in steps, where high gauge pressure is applied for a specific duration to enhance oxygen entrapment, followed by partial vacuuming to regulate bubble size distribution (APV Corporation Ltd. 1992; Cauvain et al., 2006). Consequently, the final baked structure relies on the applied vacuum and the amount of air entrapped before vacuum application. Gauge pressure is applied to shorten mixing time and control the texture

<footnote><sup>a</sup> ONIRIS - GEPEA (UMR CNRS 6144), Site de La Géraudière CS 82225, Cedex 3, 44322, Nantes, France</footnote>

<footnote><sup>b</sup> Northern Food Tec GmbH, Am Holzhafen 11 A, D-27570, Bremerhaven, Germany</footnote>

<footnote>* Corresponding author.</footnote>

<footnote>E-mail address: nasser.hamdami@oniris-nantes.fr (N. Hamdami).</footnote>
of the final baked product. In some baked products such as pizza, high volume rise is not required. So, the gauge pressure can be manipulated depending on the final baked product.

Fats are commonly known as shortenings which are used for improving the quality of baked product. Shortenings aid in retaining gas within the final product (Junge et al., 1981). They contribute to dough plasticity (Fu et al., 1997; Mehta et al., 2009), lubrication (Ghotra et al., 2002), oven spring (Chin & Campbell, 2005), loaf volume (Autio et al., 1997; Junge et al., 1981; Leissner, 1988; Mousia et al., 2007; Smith et al., 2004; Watanabe et al., 2002), crumb structure (Autio et al., 1997), tenderization (Mousia et al., 2007; Smith et al., 2004; Xu et al., 1992), and shelf life extension (Autio et al., 1997; Chin & Campbell, 2005; Delcour et al., 2010; Mousia et al., 2007; Smith et al., 2004; Xu et al., 1992). In addition to fat, salt also affects dough properties by toughening proteins and aiding in dough conditioning during mixing (Angioloni & DallaRosa, 2005). Salt has been shown to increase dough development time (DDT), extensibility, and resistance to extension (Hlynka, 1962; Beck, Jekle, & Becker, 2012a, 2012b; Fisher et al., 1949; Preston, 1981; Tanaka et al., 1967), making it crucial in mixing operations. Sheeting is another important operation in the production of products such as pizza, where the final volume of the baked product is highly dependent on the reduction of dough thickness after mixing. It plays a pivotal role in dough structure development (Qi et al., 2008). The power requirement during sheeting is heavily influenced by fat and salt content in the dough. The addition of fat up to a certain threshold level is known to decrease power requirement, but beyond that level, it exhibits a reverse trend of increasing power requirement (Raghavan et al., 1996). Salt addition to the recipe has been shown to increase power requirement (Diler et al., 2016; Kim et al., 2022). Despite significant effects of ingredients on sheeting, few studies have investigated the underlying mechanisms.

Baking is a process where crucial phenomena such as starch gelatination and gluten reticulation occur within the dough as water content reduces (Fessas & Schiraldi, 2001; Cappelli et al., 2021), typically within the temperature range of 60–85 °C, leading to the transition from dough to crumb. Ingredients significantly influence the final dough structure, particularly concerning the geometric stability of the baked product. To our knowledge, there has been no comprehensive study to date that simultaneously investigates the effects of salt, fat, and mixing pressure on pizza dough. While individual studies have examined the influence of these factors, a holistic approach considering their combined impact is lacking. Therefore, our objectives were to study the influence of pizza dough ingredients (salt and fat), process factors (gauge pressure during mixing and different roller gaps during sheeting), and their interactions on energy parameters (DDT, SME, and APC), as well as viscoelastic properties (extensibility and stickiness) of the dough and geometric stability of the baked product.

# 2. Materials and methods

## 2.1. Ingredients

The basic ingredients used in this study included wheat flour, deionized water, salt and fat. The wheat flour used was a flour laminated T38 (low ash content used to prevent dough syruping during cold storage) provided by Rettenmeier Mehl, Horb, Germany. The flour moisture content was 14.3 g/hg (Inframatic 8600- Perten Instruments-Sweden) and the water absorption was 59.5 g/hg (Farinograph- Braender- Germany- NF V 03 717-1). The flour was stored at –24 °C to prevent any quality change during study. The flour was equilibrated at 4 °C by keeping it for 48 h in a storage chamber at 4 °C, prior mixing. Salt (NaCl) provided by Les Salins du Midi - France. A specific fat mix provided by CERELIA (GESS 3925, France) was used. It contains 40 g/hg palm stearin +60 g/hg coconut oil. The fat was solid at room temperature.

## 2.2. Mixing, sheeting and baking of dough

The recipe for pizza dough is provided in Table 1. For all trials, the amounts of wheat flour and de-ionized water were kept constant at 1500 g and 654 g, respectively. The higher levels of fat and salt used in the study were determined based on the quantities currently utilized in commercial pizza dough, as outlined in Table 1. All ingredients were mixed using a planetary mixer (VMI, Montaigu Vendee, France), equipped with a spiral-shaped tool and thermos-stated with a double water jacket. The mixer's gauge pressure could be adjusted within a range from –800 mbar to +500 mbar relative to atmospheric pressure. The mixing bowl's temperature was maintained at 16 °C during mixing by a cooling water system integrated into the mixer. Mixing was conducted in two stages: the first stage was carried out for 4 min at 10 rpm and 100 rpm at atmospheric pressure, while the second stage involved higher speeds of 15 rpm and 150 rpm for 4 min at the given gauge pressure according to the experimental design. After mixing, the dough was allowed to rest for 40 min at 21 °C in a container (plastic bowl with cotton cover) in order to relax the stresses developed during mixing. Subsequently, it underwent sheeting using a twin rolls sheeter (Ron-dostar ECO SFE 6607H). Torque and temperature were monitored during sheeting, with sensors attached to the rollers. The dough sheeter was equipped with a torque sensor (T22-5NM, HBM, GmbH, Darmstadt, Germany) as well as a temperature sensor (Pt-100 temperature sensor, Germany). The dough pieces were flattened to a thickness of approximately 4 cm. A sheeting program was then used on the dough sheeter, with roller gaps set at 15.5, 12, 7.6, 5.2, 3.6, 2.2, 1.2, and 0.8 mm. The observed dough thickness after each pass was approximately 22, 15.5, 10.8, 7.6, 5.3, 3.3, 1.8, and 1.5 mm, respectively. Torque measurement was conducted after each pass through the rollers, with a 5 min resting period between passes. Sheeted dough samples were cut using a circular die (D = 10 cm). Then, it was baked for 8 min at 200 °C in a preheated convection oven (READY by LAINOX, Dim. ext.: 830 x 640 x h 595 mm) equipped with two internal fans (Jha et al., 2017).

## 2.3. Determination of the energy parameters during dough mixing

Dough development time is considered the point at which the mixer consumes the maximum power. This corresponds to the dough's peak viscosity and marks the end of the mixing process. The total mixing time up to this point is defined as the dough development time. The average power consumption for the treatments was estimated by calculating a smoothed average over 90 s, starting from when maximum power was reached. The specific mechanical energy input into the dough was calculated based on the integration of power consumption as a function of time, recorded continuously during the second mixing stage. The total energy consumed was then divided by the dough weight to obtain the SME (Farahnaky & Hill, 2007).

## 2.4. Determination of true density, apparent density and void fraction of dough

True density ($ρ_t$) is the density of the component material, excluding any interior pores that are filled with air. The air inside the sample was evacuated by maintaining a gauge pressure of –800mbar for 5 min with

<table><caption>**Table 1**

Dough recipe used in experiments.</caption><thead><tr><td>Dough recipe</td><td>Content (g)</td></tr></thead><tbody><tr><td>Flour</td><td>100</td></tr><tr><td>Water</td><td>43.6</td></tr><tr><td>Salt</td><td>2.1</td></tr><tr><td>Fat</td><td>14.8</td></tr><tr><td>Compressed yeast</td><td>0.1</td></tr><tr><td>Baking aid mix</td><td>0.6</td></tr></tbody></table>
simultaneous discharge of air at an interval of 1 min from the planetary mixer. The density of gas free dough was then measured by a gas pycnometer (Micrometrics AccuPyc 1330) with Helium at a gauge pressure of 1.5 bar as the displacement medium.

The apparent density ($ρ_{app}$) of the dough was measured using the buoyant force method, where the dough sample was weighed in air and in Rapeseed oil with a density of 0.916 kg/m³. The apparent density was calculated accordingly:

$$ρ_{app} = ρ_{l} \frac{W}{G} \qquad [1]$$

where.

$ρ_{app}$ = Apparent density, g/cm³

$ρ_l$ = Oil density, g/cm³

W = Weight of sample in air, g

G = Weight of sample in liquid, g

void fraction ($ε_{app}$) is defined as the ratio of total enclosed gas space or void volume to the apparent volume (Sahin & Sumnu, 2006). It was calculated from the values of true density and apparent density using the following equation:

$$ε_{app} = 1 - \frac{ρ_{app}}{ρ_{t}} \qquad [2]$$

## 2.5. Determination of viscoelastic properties of dough after sheeting

Extensibility and resistance to extension of the sheeted dough were measured using a texture analyzer (TA.XTplus Texture Analyser-Stable, Microsystems) equipped with Kieffer Dough & Gluten Extensibility Rig attachment. The sample preparation involved using a dough press with a grooved base and a top form. The dough clamp was wrapped with plastic film and allowed to relax for 40 min at room temperature. Subsequently, the dough strip was placed across the grooved region of the sample plate. The hook probe was then lowered onto the surface of the spring-loaded clamp. After lowering the lever of the spring-loaded clamp, the sample plate was inserted into the rig, and the handle was slowly released to conduct the test. The hook probe extended the dough sample centrally until it ruptured. The extensibility of the dough (distance to break) in millimeters and its resistance to extension (maximum force) in grams were determined.

The stickiness of the sheeted dough was measured using the SMS/Chen-Hoseney dough stickiness rig (A/DSC) and a 25 mm Perspex cylinder probe (P/25P) with a texture analyzer (TA.XTplus Texture Analyser-Stable, Microsystems). Sample preparation and testing procedures were conducted according to Grausgruber et al. (2003). Ten measurements were taken for the given dough sample. The texture analyzer settings for extensibility measurements and stickiness tests are given in Table 2.

<table><caption>**Table 2**
Extensibility and Stickiness measurement settings.</caption><thead><tr><th rowspan="2">Parameters</th><th colspan="2">Setting</th></tr><tr><th>Extensibility</th><th>Stickiness</th></tr></thead><tbody><tr><td>Pre-test speed</td><td>2 mm/s</td><td>0.5 mm/s</td></tr><tr><td>Test speed</td><td>3.3 mm/s</td><td>0.5 mm/s</td></tr><tr><td>Post-test speed</td><td>10 mm/s</td><td>10 mm/s</td></tr><tr><td>Applied force</td><td>-</td><td>40 g</td></tr><tr><td>Contact time</td><td>-</td><td>0.1 s</td></tr><tr><td>Return distance</td><td>-</td><td>4 mm</td></tr><tr><td>Distance</td><td>80 mm</td><td></td></tr><tr><td>Trigger Type</td><td>Auto</td><td>Auto</td></tr><tr><td>Trigger force</td><td>5 g</td><td>5 g</td></tr><tr><td>Trigger distance</td><td>2 mm</td><td>-</td></tr><tr><td>Load cell</td><td>2 mm/s</td><td>5 kg</td></tr></tbody></table>

## 2.6. Determination of geometric deformation of dough during baking

Geometric deformation was characterized by capturing images of the dough samples using a camera setup (Sony Corporation with an objective lens of 1/9 mm) and processed using image analysis software (VISILOG 7.1). The raw images were calibrated, converted, and analyzed to determine dimensional changes before and after baking. The percent change in values of length; width and equivalent diameter before and after baking were calculated (Fig. S1) (Jha et al., 2017).

## 2.7. Experimental design and statistical analyses

First, a four level factorial design with three replications was used to identify the effect of salt and fat on the DDT, SME and APC. The particulars of the experimental design are shown in Table 3. Next, a Box-Behnken experimental design was used to investigate the effect of salt, salt and gauge pressure on the void fraction, extensibility, stickiness, sheeting torque and baked product stability (Table 4). Box-Behnken model is having advantages over 3-level full factorial design and central composite design a way that it permits the estimation of the parameters of the quadratic model, detection of lack of fit of the model and also allows the use of blocks (Ferreira et al., 2007).

Statistical analyses were conducted using IBM SPSS Statistics 20 and Design Expert 8.0.7.1, with quadratic models fitted to the experimental data to describe the relationships between independent variables and responses Eq. (3).

$$Y = β_0 + \sum_{i=1}^{j} β_i X_i + \sum_{i=1}^{j} β_{ii} X_i^2 + \sum_{i=1}^{k-1} \sum_{j=i+1}^{k} β_{ij} X_i X_j + ε \qquad [3]$$

where Y is the response, i and j are the linear and quadratic coefficients, respectively; $X_i$ and $X_j$ are the uncoded independent parameters; k represents the number of studied and optimized variables in this study; $β_0$ is the constant coefficient; $β_i$, $β_{ii}$, and $β_{ij}$ are the interaction coefficients of linear, quadratic and second-order terms, respectively; and lastly, $ε$ is the error that occurred. ANOVA and Fisher's F-test were used to assess the model's efficiency, and three-dimensional response surface plots were utilized to represent interactions between variables.

# 3. Results and discussion

## 3.1. Effect of salt and fat on the mixing energy parameters of dough

The statistical analysis of data for DDT, APC and the SME using Analysis of variance (ANOVA) indicated that fat, salt and their interaction effects had a significant effect (Table 5). The DDT for different amount of salt and fat is shown in Figures (1a,b). Figure (1a) illustrates the significant effect of salt on development time, with time requirements increasing with salt content. Such an increase in DDT with increase in salt concentration can be due to a decrease in water absorption, thereby delaying the formation of gluten network which is the end point of mixing. When salt is added to a dough, $Na^+$ and $Cl^-$ ions interact with polar binding sites of gluten protein and compete with water for them (Jekle & Becker, 2011). Simultaneously, salt solutes increase the osmotic pressure in the aqueous phase, resulting in an osmotic stress for the yeasts. These effects are probably results in slowed gluten

<table><caption>**Table 3**
Variables of Box-Behnken design and their levels for mixing characteristics.</caption><thead><tr><th rowspan="2">No.</th><th rowspan="2">Variable</th><th colspan="4">Level</th></tr><tr><th>1</th><th>2</th><th>3</th><th>4</th></tr></thead><tbody><tr><td>1</td><td>A (Salt content, g)</td><td>0</td><td>10.5</td><td>21</td><td>31.5</td></tr><tr><td>2</td><td>B (Fat content, g)</td><td>0</td><td>74</td><td>148</td><td>222</td></tr></tbody></table>

Wheat flour and water were kept constant at 1500 g and 654 g respectively for all trials.
<table><caption>**Table 4**
Variables of Box-Behnken design and their levels.</caption><thead><tr><th rowspan="2">No.</th><th rowspan="2">Variable</th><th colspan="3">Level</th></tr><tr><th>-1</th><th>0</th><th>1</th></tr></thead><tbody><tr><td>1</td><td>X<sub>1</sub> (Salt content, g)</td><td>0</td><td>15.75</td><td>31.50</td></tr><tr><td>2</td><td>X<sub>2</sub> (Fat content, g)</td><td>0</td><td>111</td><td>222</td></tr><tr><td>3</td><td>X<sub>3</sub> (Gauge pressure, mbar)</td><td>-600</td><td>-300</td><td>0</td></tr></tbody></table>

Wheat flour and water were kept constant at 1500 g and 654 g respectively for all trials.

<table><caption>**Table 5**
Analysis of variance (ANOVA) for Factorial design (FD).</caption><thead><tr><th rowspan="2">Source of variation</th><th rowspan="2">Code</th><th rowspan="2">Degree of freedom</th><th colspan="3">Sum of squares</th></tr><tr><th>DDT</th><th>APC</th><th>SEI</th></tr></thead><tbody><tr><td>Factor 1</td><td>A</td><td>3</td><td>114.89*</td><td>16218.60*</td><td>1481.23*</td></tr><tr><td>Factor 2</td><td>B</td><td>3</td><td>11.59*</td><td>115844.09*</td><td>9557.94*</td></tr><tr><td>Interaction</td><td>A × B</td><td>9</td><td>16.31*</td><td>17193.57*</td><td>2474.19*</td></tr><tr><td>Error</td><td></td><td>32</td><td>0.504</td><td>700.13</td><td>1968.19</td></tr><tr><td>Total</td><td></td><td>47</td><td>143.29</td><td>149956.36</td><td>15481.56</td></tr></tbody></table>

<figure><img src="image_3.png" /></figure>

<figure><img src="image_4.png" /><figcaption>**Fig. 1.** Dough development time (min) as a function of salt (a) or fat (b) during atmospheric mixing.</figcaption></figure>

hydration and hence in increased development time, together with reduced water absorption (Carcea et al., 2020). Similar observations were reported by Carcea et al., 2020; Beck et al., 2012a, 2012b; Preston, 1981.

Figure (1b) shows that DDT stayed constant until 150 g of fat and tends to increase with higher fat content. With minimal fat, the gluten network form more easily and quickly, leading to a more elastic dough in a shorter period. As fat content rises, fat interferes with gluten formation by coating the flour particles resulting in a delayed hydration of the gluten proteins. This resulted in a slower gluten network formation

for high contents of fat and longer DDT. Fats with β' polymorphic crystal structures (e.g., palm fat) creates a more significant barrier due to its solid nature at room temperature (Addo & Pomeranz, 1991; Chin & Campbell, 2005; Daniels et al., 1970).

Dough ingredients significantly influence APC and SME during mixing. The effects of salt and fat on APC and SME are shown in Figures (2a,b) and (3a,b), respectively. Figures (2a) and (4a) show that after an initial increase with salt addition, they decrease with adding the salt. Dough development involves the hydration of gluten protein and the formation of interactions between glutenins and gliadins (Belton, 1999). During mixing, glutenins tend to align and form cross-links between glutenin molecules leading to an increase in dough strength. Full-charged ions Na⁺ and Cl⁻ probably establish strong polar interactions with gluten proteins that lead to a stabilized gluten network, so that strength and machinability of dough is improved and caused a decrease in APC and SME of mixing with increasing the salt content (Farahnaky & Hill, 2007; Kojima et al., 1995)). Beck et al. (2012a, 2012b) observed less linkages between proteins and elongated protein structures in the dough with 20 g NaCl kg⁻¹ flour compared to 40 g NaCl kg⁻¹ flour. This reduction in dough stability by decreasing NaCl content was explained by charge shielding effect of Na and Cl ions which does not allow the protein side chains to approach each other leading to a weaker gluten network formation and higher degree of softening and stickiness. Without salt addition, the protein structure changed from elongated protein strands to very less connected protein particles and weaken dough.

Figures (2b) and (3b) show that power consumption and specific energy of mixing decrease linearly with increasing the fat content. A function of shortening in bread dough is lubrication (Ghotra et al., 2002). Watanabe et al. (2002) suggested that added solid lipid is distributed within the gluten network between the starch granules and leads to formation of thin and easily expandable gluten films with less tendency to contract than when no lipid or liquid oil is added.

<figure><img src="image_5.png" /></figure>

<figure><img src="image_6.png" /><figcaption>**Fig. 2.** Average power consumption (W) as a function of salt (a) or fat (b) during atmospheric mixing.</figcaption></figure>

<footnote>* Significant at (p < 0.05).</footnote>
<figure><img src="image_7.png" /></figure>

<figure><img src="image_8.png" /><figcaption>**Fig. 3.** Specific mechanical energy (kJ/kg) as a function of salt (a) or fat (b) during atmospheric mixing.</figcaption></figure>

<figure><img src="image_9.png" /><figcaption>**Fig. 4.** Response surface plot showing the change in void fraction (%) as a function of salt content (g) and gauge pressure (mbar) at the fat content of zero.</figcaption></figure>

## 3.2. Effect of fat, salt and gauge pressure during mixing on the void fraction of dough

The values of apparent density and gas-free dough density are presented in Table 6. The void fraction (%) calculated at the end of mixing from the apparent density and gas-free dough densities is shown in Figure (S2) for different combinations of treatments of the Box-Behnken model. It was observed that the sample with 31.5g salt and 111g fat at atmospheric pressure showed the maximum void fraction value of 29.66%, while the lowest void fraction value of 4.22% was for the sample with 15.75g salt without fat at a gauge pressure of -600mbar. Thus, void fraction was observed to be higher when mixing was carried out at atmospheric pressure. ANOVA was conducted by fitting a quadratic model and is presented in Table 6. It can be seen that salt and gauge pressure had a significant effect on the void fraction values. The interaction effect between salt and gauge pressure was also found to be significant in the void fraction values. The fitted quadratic equation in

<table><caption>**Table 6**
Experimental values of the different dependent variables at the different levels of independent variables according to the applied Box-Behnken design (BBD).</caption><thead><tr><th rowspan="3">Run</th><th colspan="4">Independent variables</th><th colspan="10">Values of dependent variables</th></tr><tr><th rowspan="2">X<sub>1</sub><br>(g)</th><th rowspan="2">X<sub>2</sub><br>(g)</th><th rowspan="2">X<sub>3</sub><br>(mbar)</th><th rowspan="2">AD<br>(g/cm<sup>3</sup>)</th><th colspan="2">SD</th><th colspan="2">AP</th><th colspan="2">ST</th><th colspan="2">RE</th><th colspan="2">Ex</th><th colspan="2">St</th><th colspan="2">WA</th><th colspan="2">Coh</th><th colspan="2">ED</th><th colspan="2">L/D</th><th rowspan="2">Ratio</th></tr><tr><th>(g/cm<sup>3</sup>)</th><th>(%)</th><th>(N-m)</th><th>(g)</th><th>(g)</th><th>(g)</th><th>(g)</th><th>(g)</th><th>(g)</th><th>(g)</th><th>(g)</th><th>(g)</th><th>(g)</th><th>(g)</th><th>(g)</th><th>(g)</th><th>(g)</th><th>(g)</th><th>(g)</th><th>(g)</th><th>(g)</th><th>(g)</th><th>(g)</th></tr><tr><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th></tr><tr><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th></tr></thead><tbody><tr><td>1</td><td>15.75</td><td>222</td><td>0</td><td>1.089</td><td>1.263</td><td>13.79</td><td>3.0784</td><td>2.833</td><td>3.109</td><td>2.925</td><td>2.833</td><td>2.895</td><td>2.955</td><td>2.986</td><td>12.25</td><td>11.87</td><td>11.775</td><td>0.3585</td><td>0.5427</td><td>5.74</td><td>4.60</td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>2</td><td>31.50</td><td>111</td><td>-600</td><td>1.215</td><td>1.288</td><td>5.69</td><td>3.3131</td><td>3.058</td><td>3.262</td><td>3.211</td><td>3.048</td><td>3.344</td><td>3.456</td><td>3.241</td><td>12.39</td><td>10.99</td><td>3.853</td><td>0.1002</td><td>0.3840</td><td>5.35</td><td>4.68</td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>3</td><td>15.75</td><td>111</td><td>-300</td><td>1.171</td><td>1.278</td><td>8.43</td><td>2.9865</td><td>3.099</td><td>3.099</td><td>3.129</td><td>3.129</td><td>2.925</td><td>3.180</td><td>2.915</td><td>14.90</td><td>39.18</td><td>8.375</td><td>0.2578</td><td>0.4737</td><td>4.51</td><td>4.61</td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>4</td><td>0.00</td><td>111</td><td>-600</td><td>1.205</td><td>1.270</td><td>5.10</td><td>2.9661</td><td>2.742</td><td>3.109</td><td>2.956</td><td>2.752</td><td>2.854</td><td>3.037</td><td>2.915</td><td>11.54</td><td>8.438</td><td>6.557</td><td>0.1828</td><td>0.4580</td><td>6.45</td><td>3.31</td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>5</td><td>15.75</td><td>111</td><td>-300</td><td>1.169</td><td>1.277</td><td>8.46</td><td>3.2110</td><td>3.129</td><td>3.293</td><td>3.149</td><td>3.191</td><td>3.201</td><td>3.353</td><td>3.195</td><td>14.59</td><td>39.45</td><td>8.378</td><td>0.2566</td><td>0.4780</td><td>4.50</td><td>4.60</td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>6</td><td>15.75</td><td>111</td><td>-300</td><td>1.157</td><td>1.279</td><td>9.52</td><td>3.1294</td><td>3.242</td><td>3.344</td><td>3.293</td><td>3.109</td><td>3.272</td><td>3.323</td><td>3.160</td><td>13.39</td><td>39.02</td><td>8.376</td><td>0.2567</td><td>0.4744</td><td>4.51</td><td>4.60</td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>7</td><td>15.75</td><td>0</td><td>-600</td><td>1.243</td><td>1.297</td><td>4.22</td><td>3.6806</td><td>3.262</td><td>3.649</td><td>3.476</td><td>3.446</td><td>3.528</td><td>3.772</td><td>3.415</td><td>22.26</td><td>60.18</td><td>6.106</td><td>0.1681</td><td>0.4420</td><td>5.20</td><td>1.90</td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>8</td><td>15.75</td><td>111</td><td>-300</td><td>1.156</td><td>1.280</td><td>9.73</td><td>3.4050</td><td>3.068</td><td>3.242</td><td>3.129</td><td>3.048</td><td>3.160</td><td>3.231</td><td>3.017</td><td>14.67</td><td>39.08</td><td>8.376</td><td>0.2560</td><td>0.4792</td><td>4.49</td><td>4.61</td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>9</td><td>0.00</td><td>111</td><td>0</td><td>1.135</td><td>1.272</td><td>10.77</td><td>3.0784</td><td>2.905</td><td>3.017</td><td>2.905</td><td>2.905</td><td>2.895</td><td>3.057</td><td>2.935</td><td>11.48</td><td>38.83</td><td>11.34</td><td>0.3458</td><td>0.5353</td><td>4.92</td><td>2.21</td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>10</td><td>31.50</td><td>0</td><td>-300</td><td>1.208</td><td>1.300</td><td>7.44</td><td>3.1498</td><td>3.027</td><td>3.282</td><td>3.303</td><td>3.232</td><td>3.446</td><td>3.598</td><td>3.385</td><td>25.21</td><td>44.34</td><td>8.452</td><td>0.2427</td><td>0.4858</td><td>3.31</td><td>3.87</td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>11</td><td>15.75</td><td>222</td><td>-600</td><td>1.194</td><td>1.256</td><td>4.94</td><td>3.2110</td><td>2.956</td><td>3.048</td><td>2.976</td><td>2.915</td><td>3.038</td><td>3.252</td><td>3.139</td><td>9.223</td><td>7.059</td><td>8.199</td><td>0.2390</td><td>0.4779</td><td>4.26</td><td>4.71</td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>12</td><td>31.50</td><td>111</td><td>0</td><td>1.087</td><td>1.545</td><td>29.66</td><td>2.8640</td><td>2.844</td><td>3.038</td><td>2.884</td><td>3.027</td><td>2.976</td><td>3.221</td><td>2.823</td><td>18.19</td><td>29.74</td><td>9.878</td><td>0.2920</td><td>0.5096</td><td>8.19</td><td>3.75</td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>13</td><td>15.75</td><td>0</td><td>-300</td><td>1.162</td><td>1.298</td><td>10.47</td><td>3.5785</td><td>3.098</td><td>3.374</td><td>3.068</td><td>3.078</td><td>3.262</td><td>3.425</td><td>3.231</td><td>19.11</td><td>42.15</td><td>6.057</td><td>0.1655</td><td>0.4358</td><td>6.70</td><td>4.59</td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>14</td><td>15.75</td><td>111</td><td>-300</td><td>1.159</td><td>1.281</td><td>9.55</td><td>2.9559</td><td>3.078</td><td>3.139</td><td>2.956</td><td>2.946</td><td>2.997</td><td>3.170</td><td>2.915</td><td>14.18</td><td>39.02</td><td>8.378</td><td>0.2577</td><td>0.4767</td><td>4.50</td><td>4.61</td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>15</td><td>0.00</td><td>222</td><td>-300</td><td>1.154</td><td>1.256</td><td>8.11</td><td>3.0579</td><td>2.966</td><td>3.262</td><td>2.976</td><td>3.078</td><td>2.976</td><td>3.149</td><td>2.833</td><td>13.08</td><td>28.08</td><td>11.46</td><td>0.3531</td><td>0.5449</td><td>5.38</td><td>3.91</td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>16</td><td>31.50</td><td>222</td><td>-300</td><td>1.154</td><td>1.265</td><td>8.81</td><td>3.0682</td><td>3.017</td><td>3.139</td><td>2.884</td><td>2.833</td><td>2.884</td><td>3.262</td><td>2.967</td><td>15.85</td><td>43.54</td><td>13.68</td><td>0.4182</td><td>0.5639</td><td>5.19</td><td>5.48</td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>17</td><td>0.00</td><td>0</td><td>-300</td><td>1.198</td><td>1.281</td><td>6.48</td><td>3.1396</td><td>2.946</td><td>3.364</td><td>3.139</td><td>3.027</td><td>3.191</td><td>3.497</td><td>3.191</td><td>15.78</td><td>10.79</td><td>7.273</td><td>0.2066</td><td>0.4680</td><td>8.31</td><td>0.42</td><td></td><td></td><td></td><td></td><td></td></tr></tbody></table>
<table><caption>**Table 7**
Analysis of variance (ANOVA) of the different dependent variables according to the applied box-behken design (BBD).</caption><thead><tr><th rowspan="3">Source of variation</th><th rowspan="3">Degree of freedom</th><th colspan="2">Sum of squares</th><th colspan="2">ST</th><th colspan="2">(N-m)</th><th colspan="2">12</th><th colspan="2">7.6</th><th colspan="2">5.2</th><th colspan="2">3.6</th><th colspan="2">2.2</th><th colspan="2">1.2</th><th colspan="2">0.8</th><th colspan="2">RE</th><th colspan="2">Ex</th><th colspan="2">St</th><th colspan="2">WAd</th><th colspan="2">WCo</th><th colspan="2">ED</th><th colspan="2">L/D</th><th rowspan="3">Ratio (%)</th></tr><tr><th>AP</th><th>(%)</th><th>AP</th><th>(N-m)</th><th>AP</th><th>(%)</th><th>AP</th><th>(N-m)</th><th>AP</th><th>(%)</th><th>AP</th><th>(N-m)</th><th>AP</th><th>(%)</th><th>AP</th><th>(N-m)</th><th>AP</th><th>(%)</th><th>AP</th><th>(N-m)</th><th>AP</th><th>(%)</th><th>AP</th><th>(N-m)</th><th>AP</th><th>(%)</th><th>AP</th><th>(N-m)</th><th>AP</th><th>(%)</th></tr><tr><th>9</th><th></th><th>15.5</th><th></th><th>15.5</th><th></th><th>15.5</th><th></th><th>15.5</th><th></th><th>15.5</th><th></th><th>15.5</th><th></th><th>15.5</th><th></th><th>15.5</th><th></th><th>15.5</th><th></th><th>15.5</th><th></th><th>15.5</th><th></th><th>15.5</th><th></th><th>15.5</th><th></th><th>15.5</th><th></th><th>15.5</th><th></th></tr></thead><tbody><tr><td>Model</td><td></td><td>452.45*</td><td></td><td>0.5470</td><td>0.2376</td><td>0.3045</td><td>0.4043*</td><td>0.3248*</td><td>0.5990*</td><td>0.6283*</td><td>0.4637*</td><td>247.9*</td><td>0.0160</td><td>80.71*</td><td>0.0895*</td><td>0.0272*</td><td>20.54</td><td>42.03</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>X<sub>1</sub></td><td>1</td><td>61.47*</td><td></td><td>0.0029</td><td>0.0188</td><td>0.0001</td><td>0.0117</td><td>0.0178</td><td>0.0675</td><td>0.0792</td><td>0.0365</td><td>48.71*</td><td>0.0013</td><td>0.0734</td><td>0.00015</td><td>0.00049</td><td>2.125</td><td>0.8618</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>X<sub>2</sub></td><td>1</td><td>6.194</td><td></td><td>0.1604</td><td>0.0394</td><td>0.1547</td><td>0.1875*</td><td>0.1576*</td><td>0.1576*</td><td>0.3334*</td><td>0.3502*</td><td>0.2100*</td><td>0.0021</td><td>37.10*</td><td>0.0429*</td><td>0.0111*</td><td>0.4284</td><td>21.89*</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>X<sub>3</sub></td><td>1</td><td>239.05*</td><td></td><td>0.0408</td><td>0.0142</td><td>0.0352</td><td>0.0876</td><td>0.0125</td><td>0.0675</td><td>0.0919</td><td>0.0675</td><td>3.942</td><td>0.0050</td><td>25.69*</td><td>0.0278*</td><td>0.0085*</td><td>2.311</td><td>0.0375</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>X<sub>1</sub> * X<sub>2</sub></td><td>1</td><td>0.0156</td><td></td><td>0.0000</td><td>0.0002</td><td>0.0004</td><td>0.0163</td><td>0.0504</td><td>0.0301</td><td>0.0000</td><td>0.0009</td><td>11.11</td><td>0.0008</td><td>0.2704</td><td>0.0002</td><td>0.0000</td><td>3.406</td><td>12.96*</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>X<sub>1</sub> * X<sub>3</sub></td><td>1</td><td>74.58*</td><td></td><td>0.0788</td><td>0.0357</td><td>0.0044</td><td>0.0190</td><td>0.0075</td><td>0.0417</td><td>0.0163</td><td>0.0482</td><td>8.593</td><td>0.0003</td><td>0.387</td><td>0.0002</td><td>0.0006</td><td>4.799</td><td>0.0078</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>X<sub>2</sub> * X<sub>3</sub></td><td>1</td><td>1.688</td><td></td><td>0.0002</td><td>0.0004</td><td>0.0284</td><td>0.0319</td><td>0.0204</td><td>0.0038</td><td>0.0007</td><td>0.0002</td><td>9.547</td><td>0.0010</td><td>3.285</td><td>0.0037</td><td>0.0013</td><td>0.000028</td><td>1.956</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>X<sub>2</sub><sup>2</sup></td><td>1</td><td>11.32</td><td></td><td>0.1405</td><td>0.0854</td><td>0.0237</td><td>0.0334</td><td>0.0330</td><td>0.0237</td><td>0.0012</td><td>0.0273</td><td>0.7077</td><td>0.0004</td><td>3.087</td><td>0.0022</td><td>0.0014</td><td>4.530</td><td>0.1088</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>X<sub>2</sub><sup>2</sup></td><td>1</td><td>39.62</td><td></td><td>0.0935</td><td>0.0003</td><td>0.0545</td><td>0.0047</td><td>0.0092</td><td>0.0328</td><td>0.0844*</td><td>0.0753*</td><td>31.15*</td><td>0.0003</td><td>4.078</td><td>0.0027</td><td>0.0019</td><td>0.3389</td><td>0.3872</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>X<sub>2</sub><sup>2</sup></td><td>1</td><td>21.98</td><td></td><td>0.0426</td><td>0.0371</td><td>0.0074</td><td>0.0120</td><td>0.0167</td><td>0.0015</td><td>0.0075</td><td>0.0015</td><td>7.789</td><td>0.0044</td><td>7.407</td><td>0.0103</td><td>0.0022</td><td>1.998</td><td>3.875</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>Residual</td><td>7</td><td>69.07</td><td></td><td>0.2170</td><td>0.0708</td><td>0.1098</td><td>0.0618</td><td>0.1062</td><td>0.1066</td><td>0.0793</td><td>0.0804</td><td>16.04</td><td>0.0091</td><td>14.09</td><td>0.0146</td><td>0.0050</td><td>9.772</td><td>11.17</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></tbody></table>

* Significant at (p < 0.05).

terms of void fraction is shown in Table 8. Figure (4) illustrate the impact of gauge pressure and salt on the void fraction. It can be deducted that the void fraction of the dough increases with the increase in salt content and gauge pressure. Mixing develops the dough into a three-dimensional viscoelastic structure with gas-retaining properties and incorporates air which will form nuclei for gas bubbles that grow during dough fermentation (Bloksma & Bushuk, 1988; Collado & Leyn, 2000; Dobraszczyk & Morgenstern, 2003; Naeem et al., 2002). The volume rising property of bread dough is related to gas production, gas holding capacity and dough elasticity. Salt addition to the dough increase the dough elasticity and its gas holding capacity. These results in an increase of dough void fraction. Shortening has a positive impact on air incorporation during mixing, although it was not statistically significant here. Olcott and Mecham (1947) noted that the lipid content of flour and the interaction with the starch portion of dough, is much responsible for gas retention. Using a partial vacuum, the dough will be degassed and less aerated, resulting in weaker gluten networks. However, this can be beneficial for certain applications, such as ready-to-bake sheeted dough.

### 3.3. Effect of salt, fat and gauge pressure on the torque requirement during sheeting

The maximum torque recorded when the dough was passed between the rolls is presented in Table (6) for different roller gaps. The higher values of torque were recorded for the samples without the fat. The ANOVA table for different roller gaps is shown in Table (7). At higher roller gaps (7.6, 12 and 15.5 mm), the ingredients and the gauge pressure level were not found to affect the torque. Interaction effects between the ingredients were not observed. However, the sheeting torque was significantly affected by the fat content at lower roller gaps (<5.2 mm). For a roller gap of 0.8 mm, it can be seen that the measured torque decreased with fat content (Fig. 5). Similar trends were observed for roller gaps of 5.2, 3.6, 2.2 and 1.2 mm. This result was consistent with the study conducted by Raghavan et al. (1996). Shortening plasticises dough (Fu et al., 1997). Fat increases hydrophobic interactions, preventing an extensive gluten network, leading to a shorter dough structure that requires less sheeting torque.

The coefficients of fitted quadratic equations for torque as a function of salt, fat and gauge pressure at different roller gaps are given in Table (8). The R² values show that the predicted models are valid (Lee, 2007).

### 3.4. Effect of fat, salt and gauge pressure on the visco-elastic properties of sheeted dough

The values of extensibility (mm) and resistance to extension (g force) measured after sheeting for different dough samples are shown in Figure (S3) and Table (6). ANOVA for extensibility and resistance to extension was carried out by fitting a quadratic model (Table 7). It can be observed that the resistance to extension values of the sheeted dough were significantly affected by the salt and fat content. However, the ingredients and the gauge pressure level were not found to affect the extensibility, significantly.

Figure (6) presents the evolution of the resistance to extension values as a function of salt and fat contents at the gauge pressure of zero. It can be seen that the resistance to extension increases with increasing the salt content and decreasing the fat.

Many studies have shown that sodium chloride increases the dough resistance, elasticity and extensibility (Uthayakumaran, 2011). It is well documented that NaCl alters the viscoelastic properties of dough by increasing the level of gluten protein interactions via charge shielding on the proteins (Belz et al., 2012; Miller & Hoseney, 2008; Uthayakumaran, 2011). Fats create films between gluten strands and starch granules and disrupting gluten's elastic structure (Mehta et al., 2009). Tan δ, which measures dough plasticity, increases over time, showing changes in dough viscosity. Thus, fat and salt play contradicting roles in
<table><caption>**Table 8**
Coefficients of independent variables of function (βn) by response surface quadratic regression for the different dependent variables.</caption><thead><tr><th rowspan="2">Responses (Y)</th><th colspan="11">Coefficients for independent variables</th></tr><tr><th>Constant</th><th>X<sub>1</sub></th><th>X<sub>2</sub></th><th>X<sub>3</sub></th><th>X<sub>1</sub>X<sub>2</sub></th><th>X<sub>1</sub>X<sub>3</sub></th><th>X<sub>2</sub>X<sub>3</sub></th><th>X<sub>1</sub><sup>2</sup></th><th>X<sub>2</sub><sup>2</sup></th><th>X<sub>3</sub><sup>2</sup></th><th>R<sup>2</sup></th><th>Adj. R<sup>2</sup></th><th>Pre. R<sup>2</sup></th></tr></thead><tbody><tr><td>AP (%)</td><td>6.78</td><td>0.25</td><td>0.07</td><td>0.017</td><td>-3.57E-05</td><td>9.14E-04</td><td>1.95E-05</td><td>6.61E-03</td><td>-2.49E-04</td><td>2.54E-05</td><td>0.87</td><td>0.84</td><td>0.80</td></tr><tr><td rowspan="5">ST (N.m), in different roller gaps (mm)</td><td>15.5</td><td>3.4</td><td>0.016</td><td>-4.03E-03</td><td>9.25E-04</td><td>-3.18E-20</td><td>-2.97E-05</td><td>-2.30E-07</td><td>-7.37E-04</td><td>1.21E-05</td><td>1.12E-06</td><td>0.92</td><td>0.90</td><td>0.85</td></tr><tr><td>12</td><td>2.95</td><td>0.016</td><td>-6.18E-04</td><td>-4.86E-04</td><td>-4.38E-06</td><td>-2.00E-05</td><td>3.07E-07</td><td>-5.74E-04</td><td>6.63E-07</td><td>-1.04E-06</td><td>0.87</td><td>0.85</td><td>0.79</td></tr><tr><td>7.6</td><td>3.24</td><td>7.85E-03</td><td>-2.45E-03</td><td>-6.70E-04</td><td>-5.84E-06</td><td>-7.02E-06</td><td>2.53E-06</td><td>-3.02E-04</td><td>9.24E-06</td><td>-4.65E-07</td><td>0.84</td><td>0.81</td><td>0.77</td></tr><tr><td>5.2</td><td>2.95</td><td>0.013</td><td>-6.02E-04</td><td>-7.72E-04</td><td>-3.65E-05</td><td>-1.46E-05</td><td>2.68E-06</td><td>-3.59E-04</td><td>2.71E-06</td><td>-5.93E-07</td><td>0.87</td><td>0.84</td><td>0.81</td></tr><tr><td>3.6</td><td>2.89</td><td>0.019</td><td>-4.51E-04</td><td>-6.46E-04</td><td>-6.42E-05</td><td>-9.18E-06</td><td>2.15E-06</td><td>-3.57E-04</td><td>3.79E-06</td><td>-7.00E-07</td><td>0.82</td><td>0.79</td><td>0.79</td></tr><tr><td rowspan="2">2.2</td><td>3.11</td><td>0.014</td><td>-2.37E-03</td><td>-1.94E-04</td><td>-4.96E-05</td><td>-2.16E-05</td><td>9.19E-07</td><td>-3.02E-04</td><td>7.17E-06</td><td>-2.10E-07</td><td>0.85</td><td>0.81</td><td>0.78</td></tr><tr><td>1.2</td><td>3.39</td><td>4.21E-03</td><td>-4.34E-03</td><td>-4.68E-04</td><td>1.46E-06</td><td>-1.35E-05</td><td>3.83E-07</td><td>-6.69E-05</td><td>1.15E-05</td><td>-4.68E-07</td><td>0.89</td><td>0.87</td><td>0.82</td></tr><tr><td rowspan="2">0.8</td><td>3.2</td><td>8.53E-03</td><td>-3.66E-03</td><td>1.60E-04</td><td>-8.77E-06</td><td>-2.32E-05</td><td>2.30E-07</td><td>-3.25E-04</td><td>1.09E-05</td><td>2.11E-07</td><td>0.85</td><td>0.83</td><td>0.78</td></tr><tr><td>13.67</td><td>0.3</td><td>-0.06</td><td>-0.02</td><td>-9.53E-04</td><td>3.10E-04</td><td>4.64E-05</td><td>1.65E-03</td><td>2.21E-04</td><td>-1.51E-05</td><td>0.94</td><td>0.91</td><td>0.87</td></tr><tr><td>St (g)</td><td>7.67</td><td>-0.11</td><td>7.49E-03</td><td>-6.93E-03</td><td>1.49E-04</td><td>6.58E-05</td><td>2.72E-05</td><td>3.45E-03</td><td>7.99E-05</td><td>-1.47E-05</td><td>0.85</td><td>0.82</td><td>0.77</td></tr><tr><td>WA (g,s)</td><td>0.22</td><td>-3.18E-03</td><td>4.12E-04</td><td>2.60E-04</td><td>4.14E-06</td><td>1.52E-06</td><td>9.17E-07</td><td>9.19E-05</td><td>2.06E-06</td><td>-5.51E-07</td><td>0.86</td><td>0.83</td><td>0.79</td></tr><tr><td>Coh (mm)</td><td>0.47</td><td>-2.06E-03</td><td>1.13E-04</td><td>-1.43E-04</td><td>1.72E-07</td><td>2.56E-06</td><td>5.33E-07</td><td>7.33E-05</td><td>1.71E-06</td><td>-2.54E-07</td><td>0.84</td><td>0.80</td><td>0.77</td></tr><tr><td>ED (cm)</td><td>7.63</td><td>-0.15</td><td>-0.015</td><td>2.74E-03</td><td>5.28E-04</td><td>2.32E-08</td><td>-7.88E-04</td><td>4.18E-03</td><td>2.30E-05</td><td>7.65E-06</td><td>0.68</td><td>0.64</td><td>0.61</td></tr><tr><td>L/W</td><td>0.73</td><td>0.16</td><td>0.019</td><td>-3.98E-03</td><td>-1.03E-03</td><td>9.33E-06</td><td>-2.10E-05</td><td>-6.48E-04</td><td>2.46E-05</td><td>-1.07E-05</td><td>0.89</td><td>0.86</td><td>0.82</td></tr></tbody></table>

<caption>**Fig. 5.** Response surface plot showing the change in the sheeting torque (N,m) as a function of fat content (g) and gauge pressure (mbar) at the salt content of zero for a roller gap of 0.8 mm.</caption>

the structural integrity of the dough, and therefore, an optimum quantity makes the dough more plastic and less weak.

The values of stickiness (g), work of adhesion (g.s), and cohesiveness (mm) measured after sheeting for different dough samples are shown in Figure (S4) and Table (6). The highest values for all stickiness, work of adhesion, and cohesiveness were observed in the samples with higher salt and fat contents. The fitted quadratic equation in terms of cohesiveness, stickiness, and work of adhesion were presented in Tables (7 and 8). From Table (7), it can be observed that stickiness, cohesiveness, and work of adhesion values were significantly affected by the fat and gauge pressure level. Figure (7) illustrates that the stickiness value decreased with decreasing the gauge pressure and fat content. Vacuum mixing creates stress-free dough and can improve dough plasticity and

<caption>**Fig. 6.** Response surface plot showing the change in resistance to extension (g force) as a function of salt and fat contents (g) at the gauge pressure of zero.</caption>

reduce stickiness and surface moisture. It is noted that using over-pressure (1 bar) the dough become elastic and sticky. Dough stickiness occurs when the adhesive forces (interactions between the dough surface and the mixing surface) are high and the cohesive forces (interactions within the dough) are low; i.e., weak dough (Adhikari et al., 2001; van Velzen et al., 2003). Previous studies have determined the processing factors (i.e., mixing time/speed, energy input, temperature, and relaxation time) and formulation (i.e., level of hydration, ingredients, and quality of flour) contribute to dough stickiness (Belz et al., 2012; van Velzen et al., 2003). Beck et al. (2012a, 2012b) suggested that the unbound water within dough might be responsible for dough stickiness. Unbound water in dough increased with both the fat and salt contents.

<figure><img src="image_10.png" /></figure>

<figure><img src="image_11.png" /></figure>
<figure><img src="image_12.png" /><figcaption>**Fig. 7.** Response surface plot showing the change in stickiness (g) as a function of fat content (g) and gauge pressure (mbar) at the salt content of zero.</figcaption></figure>

**3.5. Effect of salt, fat and gauge pressure on dough deformation during baking**

The length-to-width ratio of a model dough disc was measured both before and after baking. It was used to assess the dough disc deformation according to formulation and pressure. It was observed that there was a global increase in the value of the L/W ratio and a decrease in the equivalent diameter. The values of the change in the dimensions of the sheeted dough before and after baking for different samples are presented in percentage in Table (6). The largest deformation was observed in the sample without salt and 222 g fat at a gauge pressure of -300 mbar, while the smallest deformation was observed in the sample without salt and fat at the same gauge pressure (Fig. S5 and Table (6)). The ANOVA table for the change in dimensions of the equivalent diameter and L/W ratio and the fitted quadratic equations are shown in Tables (7 and 8). As shown in Table (7), the change in the equivalent diameter was not affected by the dough ingredients. However, the change in the L/W ratio was significantly (p < 0.05) affected by fat and the interaction effect of fat-salt. In Figure (8), it can be observed that there was a linear increase in the deformation with an increase in fat content without salt addition.

In the absence of added shortening, neighboring bubbles coalesce during baking, resulting in a coarser crumb structure than in the presence of shortening (Brooker, 1996). Junge and Hoseney (1981) found that dough containing shortening expands longer, i.e. to a higher temperature, and to a greater height than control dough. The effect of solid shortening on loaf volume may well be the result of a combination of both lipid crystal adsorptions at the gas cell surface and the presence of more expandable gluten films. In conclusion, when shortening is added as a dough ingredient, the bread has a more deformation than control bread (Watanabe et al., 2002, 2003). The interaction effect between fat and salt demonstrated a more complex deformation pattern than their individual main effects. When one of these components was present in high amounts, increasing the other component led to a decrease in deformation.

**4. Conclusion**

This study investigated the effects of salt and fat on pizza dough properties during mixing, sheeting, and baking. The results demonstrated that these ingredients significantly influence dough structure, particularly its viscoelasticity. The key findings can be summarized as follows.

1) DDT, SME, and APC were influenced by salt and fat content. Higher salt and fat levels extended DDT, with fat acting as a lubricant to reduce SME and APC. In contrast, doughs with salt alone exhibited

<figure><img src="image_13.png" /><figcaption>**Fig. 8.** Response surface plots showing the change in L/D ratio (%) as a function of salt and fat contents (g) at the gauge pressure of zero.</figcaption></figure>

higher energy demands, with peak APC observed in samples containing 10% salt without fat.

2) Lowering gauge pressure values significantly reduced the dough void fraction. However, this effect diminished as salt content increased, highlighting an interaction between gauge pressure and salt levels.

3) Fat addition substantially decreased torque requirements at narrower roller gaps, while reduced gauge pressures increased these requirements. Higher torque values suggest increased force and energy demands during processing.

4) Resistance to dough extension decreased with higher fat and lower salt levels, as fat enhanced dough plasticity, reducing the force needed for extension. Stickiness was also modulated by fat content and gauge pressure.

5) Deformation during baking was amplified with higher fat content, underscoring its impact on dough structure under thermal conditions.

In summary, the findings suggest that targeted reductions in fat and salt can still preserve desirable dough properties and baking performance. Specifically, optimal fat and salt contents of approximately 111 g and 15.75 g, respectively, were identified for maintaining dough plasticity and strength. This study underscores the importance of balancing these ingredients to achieve desired dough characteristics while addressing health-focused formulation goals. The insights gained can be applied in the food industry to develop a wide range of low-salt and low-fat baked goods, aligning with regulatory standards and consumer demands. However, this study did not explore the long-term effects of reduced salt and fat levels on shelf life and microbial stability or conduct sensory evaluations and consumer preference assessments. Future research should aim to address these gaps, balancing health benefits with sensory appeal and product stability to meet both consumer expectations and industry requirements.

**CRediT authorship contribution statement**

**Nair Nikhil Haridasan:** Writing – original draft, Investigation.
**Nasser Hamdami:** Writing – review & editing, Visualization, Validation, Formal analysis.
**Klaus Lösche:** Writing – review & editing, Validation.
**Alain Le-Bail:** Writing – review & editing, Validation, Supervision, Resources, Project administration, 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

The authors would thank the ONIRIS for their financial support. This study was carried out during the MSc thesis of Nikhil Nair under a Memorandum of Understanding between CFTRI (India) and ONIRIS (France).

## Appendix A. Supplementary data

Supplementary data to this article can be found online at https://doi.org/10.1016/j.lwt.2025.117410.

## Data availability

Data will be made available on request.

## References

Addo, K., & Pomeranz, Y. (1991). Lipid-binding and fatty-acid distribution in flour, dough, and baked and steamed bread. *Cereal Chemistry*, **68**, 570-572.

Adhikari, B., Howes, T., Bhandari, B. R., & Truong, V. (2001). Stickiness in foods: A review of mechanisms and test methods. *International Journal of Food Properties, 4*, 1-33. https://doi.org/10.1081/JFP-100002186

Angioloni, A., & Dalla Rosa, M. (2005). Dough thermo-mechanical properties: Influence of sodium chloride, mixing time and equipment. *Journal of Cereal Science*, **41**(3), 327-331.

APV Corporation Ltd. (1992). *Dough mixing*, Article 2264623. UK Patent.

Autio, K., & Laurikainen, T. (1997). Relationships between flour/dough microstructure and dough handling and baking properties. *Trends in Food Science & Technology*, **8**(6), 181-185.

Beck, M., Jekle, M., & Becker, T. (2012a). Impact of sodium chloride on wheat flour dough for yeast-leavened products. I. Rheological attributes. *Journal of the Science of Food and Agriculture*, **92**(3), 585-592.

Beck, M., Jekle, M., & Becker, T. (2012b). Impact of sodium chloride on wheat flour dough for yeast-leavened products. II. Baking quality parameters and their relationship. *Journal of the Science of Food and Agriculture*, **92**(2), 299-306.

Belton, P. (1999). Mini review: On the elasticity of wheat gluten. *Journal of Cereal Science*, **29**(2), 103-107.

Belz, M. C. E., Ryan, L. A. M., & Arendt, E. K. (2012). The impact of salt reduction in bread: A review. *Critical Reviews in Food Science and Nutrition, 52*, 514-524. https://doi.org/10.1080/10408398.2010.502265

Bloksma, A. H., & Bushuk, W. (1988). Rheology and chemistry of dough. *Wheat chemistry and technology* (pp. 131-217). St. Paul, MN: American Association Cereal Chemistry.

Brooker, B. E. (1996). The role of fat in the stabilisation of gas cells in bread dough. *Journal of Cereal Science*, **24**, 187-198.

Cappelli, A., Lupori, L., & Cini, E. (2021). Baking technology: A systematic review of machines and plants and their effect on final products, including improvement strategies. *Trends in Food Science & Technology*, **115**, 275-284.

Carcea, M., Narducci, V., Turfani, V., & Mellara, F. (2020). A comprehensive study on the influence of sodium chloride on the technological quality parameters of soft wheat dough. *Foods*, **9**, 952. https://doi.org/10.3390/foods9070952

Cauvain, S. P., & Young, L. S. (2006). *Baked products* (pp. 120-147). Oxford, UK: Blackwell.

Chin, N. L., & Campbell, G. M. (2005). Dough aeration and rheology: Part 2. Effects of flour type, mixing speed and total work input on aeration and rheology of bread dough. *Journal of the Science of Food and Agriculture*, **85**(13), 2194-2202.

Collado, M., & Leyn, I. D. (2000). Relationship between loaf volume and gas retention of dough during fermentation. *Cereal Foods World*, **45**, 214-218.

Crucean, D., Pontoire, B., Debucquet, G., Le-Bail, A., & Le-Bail, P. (2023). The use of choline chloride for salt reduction and texture enhancement in bread. *Applied Food Research, 3*, Article 100371.

Daniels, N. W. R., Wood, P. S., Russell, P. W., & Coppock, J. B. M. (1970). Studies on the lipids of flour V-Effect of air on lipid binding. *Journal of the Science of Food and Agriculture*, **21**(7), 377-384.

Delcour, J., & Hoseney, R. C. (2010). *Principles of cereal science and technology*. St. Paul, MN, USA: AACC International, Inc.

Diler, G., Le-Bail, A., & Chevallier, S. (2016). Salt reduction in sheeted dough: A successful technological approach. *Food Research International*, **88**, 10-15. https://doi.org/10.1016/j.foodres.2016.03.013

Dobraszczyk, B. J., & Morgenstern, M. P. (2003). Rheology and the bread making process. *Journal of Cereal Science*, **38**, 229-245. https://doi.org/10.1016/s0733-5210(03)00059-6

Farahnaky, A., & Hill, S. (2007). The effect of salt, water and temperature on wheat dough rheology. *Journal of Texture Study*, **38**, 499-510.

Ferrari, G. T., Proserpio, C., Stragliotto, L. K., Boff, J. M., Pagliarini, E., & Oliveira, V. R. (2022). Salt reduction in bakery products: A critical review on the worldwide scenario, its impacts and different strategies. *Trends in Food Science & Technology*, **129**, 440-448.

Ferreira, S. L. C., Bruns, R. E., Ferreira, H. S., Matos, G. D., David, J. M., Brandão, G. C., ... dos Santos, W. N. L. (2007). Box-Behnken design: An alternative for the optimization of analytical methods. *Analytica Chimica Acta*, **597**(2), 179-186.

Fessas, D., & Schiraldi, A. (2001). Water properties in wheat flour dough I: Classical thermogravimetry approach. *Food Chemistry*, **72**(2), 237-244.

Fisher, M. H., Aitken, T. R., & Anderson, J. A. (1949). Effects of mixing, salt, and consistency on extensograms. *Cereal Chemistry*, **26**(2), 81-97.

Fu, J., Mulvaney, S. J., & Cohen, C. (1997). Effect of added fat on the rheological properties of wheat flour doughs. *Cereal Chemistry*, **74**(3), 304-311.

Ghotra, B. S., Dyal, S. D., & Narine, S. S. (2002). Lipid shortenings: A review. *Food Research International*, **35**(10), 1015-1048.

Grausgruber, H., Hatzenbichler, E., & Ruckenbauer, P. (2003). Analysis of repeated stickiness measures of wheat dough using a texture analyzer. *Journal of Texture Studies, 34*(1), 69-82.

Hlynkva, I. (1962). Influence of temperature, speed of mixing, and salt on some rheological properties of dough in the farinograph. *Cereal Chemistry*, **39**(4), 286.

Jekle, M., & Becker, T. (2011). Dough microstructure: Novel analysis by quantification using confocal laser scanning microscopy. *Food Research International*, **44**, 984-991. https://doi.org/10.1016/j.foodres.2011.02.036

Jha, P. K., Chevallier, S., Cheio, C., Rawson, A., & Le-Bail, A. (2017). Impact of resting time between mixing and shaping on the dough porosity and final cell distribution in sandwich bread. *Journal of Food Engineering*, **194**, 15-23. https://doi.org/10.1016/j.jfoodeng.2016.07.016

Junge, R. C., & Hoseney, R. C. (1981). A mechanism by which shortening and certain surfactants improve leaf volume in bread. *Cereal Chemistry*, **58**, Article 408e412.

Kim, H., Kim, M., Ryu, A., Bae, J., Choi, Y., Lee, G., Choi, H., & Hong, J. (2022). Comparison of rheological properties between Mixolab-driven dough and bread-making dough under various salt levels. *Food Science and Biotechnology*, **32**. https://doi.org/10.1007/s10068-022-01186-w

Kojima, M., Togawa, T., Murase, M., Totani, S., Sugimoto, M., & Kaishi, N. S. (1995). Effects of addition of water and sodium chloride on microstructure and rheological properties of noodles. *Food Feed Chem.*, **42**, 899-906.

Lee, K. P. (2007). Optimization strategies for separation of sulfadiazines using Box-Behnken design by liquid chromatography and capillary electrophoresis. *Journal of Central South University of Technology*, **14**(2), 196-201.

Leissner, O. (1988). A comparison of the effect of different polymorphic forms of lipids in breadmaking. *Cereal Chemistry*, **65**.

Mehta, K. L., Scanlon, M. G., Sapirstein, H. D., & Page, J. H. (2009). Ultrasonic investigation of the effect of vegetable shortening and mixing time on the mechanical properties of bread dough. *Journal of food science*, **74**(9), E455-E461.

Miller, R. A., & Hoseney, R. C. (2008). Role of salt in baking. *Cereal Foods World*, **53**, 4-6. https://doi.org/10.1094/CFW-53-1-0004

Monteiro, A. R. G., Nakagawa, A., Pimentel, T. C., & Sousa, I. (2021). Increasing salinity perception and keeping quality properties of low salt bread using inhomogeneous salt distribution achieved with salt agglomerated by waxy starch. *LWT - Food Science and Technology*, **146**, Article 111451.

Mousia, Z., Campbell, G. M., Pandiella, S. S., & Webb, C. (2007). Effect of fat level, mixing pressure and temperature on dough expansion capacity during proving. *Journal of Cereal Science*, **46**(2), 139-147.

Naem, H. A., Darvey, N. L., Gras, P. W., & MacRitchie, F. (2002). Mixing properties, baking potential, and functionality changes in storage proteins during dough development of triticale-wheat flour blends. *Cereal Chemistry*, **79**, 332-339.

Olcott, H. S., & Mecham, D. K. (1947). Characterization of wheat gluten. I. Protein-lipid complex formation during doughing of flours. Lipoprotein nature of the glutenin fraction. *Cereal Chemistry*, **24**, 407-414.

Preston, K. R. (1981). Effects of neutral salts upon wheat gluten protein properties. I. Relationship between the hydrophobic properties of gluten proteins and their extractability and turbidity in neutral salts. *Cereal Chemistry*, **58**.

Qi, F., Dai, S. C., Newberry, M. P., Love, R. J., & Tanner, R. I. (2008). A simple approach to predicting dough sheeting thickness. *Journal of Cereal Science*, **47**(3), 489-495.

Quilez, J., Rafecas, M., Brufau, G., García-Lorda, P., Megfas, I., Bulló, M., ... Salas-Salvadó, J. (2003). Bakery products enriched with phytosterol esters, α-tocopherol and β-carotene decrease plasma LDL-cholesterol and maintain plasma β-carotene concentrations in normocholesterolemic men and women. *The Journal of nutrition*, **133**(10), 3103-3109.

Raghavan, C. V., Srichandan Babu, R., Chand, N., & Srinivasa Rao, P. N. (1996). Response surface analysis of power consumption of dough sheeting as a function of gap, reduction ratio, water, salt and fat. *Journal of food science and technology*, **33**(4), 313-321.

Ruston, D., Hoare, J., Henderson, L., Gregory, J., Bates, C. J., Prentice, A., & Farron, M. (2004). *National diet and nutrition survey: Adults aged 19 to 64 years*. London: National Statistics.

Sahin, S., & Sumnu, S. G. (2006). *Physical properties of foods*. Springer.

Santos, M., Trivino, A. P. R., Barros, J. C., Cruz, A. G., & Pollonio, M. A. R. (2023). Strategies for the reduction of salt in food products. In M. A. P. R. Cerqueira, & L. M. P. Castro (Eds.), *Food structure engineering and design for improved nutrition, health and well-being* (pp. 187-218). Boca Raton: Academic Press.

Smith, P. R., & Johansson, J. (2004). Influences of the proportion of solid fat in a shortening on loaf volume and staling of bread. *Journal of Food Processing and Preservation*, **28**(5), 359-367.

Song, Y., & Zheng, Q. (2007). Dynamic rheological properties of wheat flour dough and proteins. *Trends in food science & technology*, **18**(3), 132-138.

Sun, C., Zhou, X., Hu, Z., Lu, W., Zhao, Y., & Fang, Y. (2021). Food and salt structure design for salt reducing. *Innovative Food Science and Emerging Technologies*, **67**, Article 102570.

Tanaka, K., Furukawa, K., & Matsumot, H. (1967). Effect of acid and salt on farinogram and extensigram of dough. *Cereal Chemistry*, **44**(6), 675.

Uthayakumaran, S. (2011). Salt reduction in wheat-based foods-technical challenges and opportunities. *Food Australia*, **63**, 137-140.
van Velzen, E. J. J., van Duynhoven, J. P. M., Pudney, P., Weegels, P. L., & van der Maas, J. H. (2003). Factors associated with dough stickiness as sensed by attenuated total reflectance infrared spectroscopy. *Cereal Chemistry, 80*, 378–382. https://doi.org/10.1094/CCHEM.2003.80.4.378

Watanabe, A., Larsson, H., & Eliasson, A. C. (2002). Effect of physical state of nonpolar lipids on rheology and microstructure of gluten-starch and wheat flour doughs. *Cereal Chemistry, 79*(2), 203–209.

Watanabe, A., Yokomizo, K., & Eliasson, A. C. (2003). Effect of physical states of nonpolar lipids on rheology, ultracentrifugation, and microstructure of wheat flour dough. *Cereal Chemistry, 80*, 281–284.

Xu, A., Ponte, J. G., & Chung, O. K. (1992). Bread crumb amyograph studies. II. Cause of unique properties. *Cereal Chemistry, 69*, 502-502.

Zandstra, E. H., Lion, R., & Newson, R. S. (2016). Salt reduction: Moving from consumer awareness to action. *Food Quality and Preference, 48*, 376–381.