## 2 Materials and Methods
### In Vitro Static Digestion for the Evaluation of the Phenolic Modifications  
The harmonized INFOGEST in vitro static digestion protocol was employed [16]. Briefly, for the oral phase, 100 g of each bread were moistened with 150 mL of a salivary fluid (SF; pH = 7.0; 37 \({}^{\circ}\)C) and chopped in a commercial meat grinder equipped with a 4 mm-hole plate. Twenty-five g of the resulting oral bolus was transferred in a 50 mLblue cap glass bottle, 5 mL of the SF containing \(\alpha\)-amylase (A1031; Sigma-Aldrich; Milan, Italy; 150 U/mL; pH = 7.0; 37 \({}^{\circ}\)C) was added and then bottles containing-samples were incubated at 37 \({}^{\circ}\)C for 2 min. Then, 20 mL of a gastric fluid at pH 3.0 plus pepsin (P7012; Sigma-Aldrich; 2.000 U/mL) was added. This gastric phase lasted for 120 min at 37 \({}^{\circ}\)C. For the small intestine phase, 40 mL of an intestinal fluid at pH = 7.0 plus pancreatin (P7545; Sigma-Aldrich; Milan, Italy; 100 U/mL) and bile salts (B8631; Sigma-Aldrich; Milan, Italy; 10 mM) were added to the chyme and samples were further incubated for 120 min at 37 \({}^{\circ}\)C. In addition, HCl (1 M) and NaOH (1 M) were used for pH regulation. The composition of each simulated fluid was detailed by [PERSON] et al. [16]. Liquid aliquots were removed after the gastric and the small intestinal (i.e., pancreatic) phases and stored (i.e., \(-\)20 \({}^{\circ}\)C). Analyses were run in triplicate. Phenolic Profiling by Ultra-High-Performance Liquid Chromatography-Quadrupole-Time-of-Flight (UHPLC-QTOF) Mass Spectrometry  
The fate of polyphenols after each considered in vitro digestion phase (i.e., gastric and small intestine) was evaluated by ultra-high-performance liquid chromatography-quadrupole-time-of-flight (UHPLC-ESI/QTOF) mass spectrometry, as previously reported [15]. Collected liquid aliquots were centrifuged (7000\(\times\)\(g\); 10 min) and filtered (0.22 \(\upmu\)m). The mobile phase was a mixture of acetonitrile and water (VWR, Milan, Italy) acidified with 0.1% formic acid (\(v/v\)). The chromatographic process was done on the Agilent Zorbax Eclipse-plus C18 column (100 mm \(\times\) 2.1 mm, 1.8 \(\upmu\)m) whilst a linear gradient from 6% acetonitrile to 94% acetonitrile, produced via a binary pump, was done in 34 min, considering flow rate of 0.22 mL/min. The mass spectrometer worked in the positive (ESI+) scan mode in the range 100-1200 \(m/z\), injecting three replicates of 6 \(\upmu\)L. The injection sequence was randomized, and quality control samples (QCs) were injected and acquired using a data-dependent auto-MS/MS mode using 12 precursors per cycle (1 Hz, 80-1200 \(m\)/z, positive polarity, active exclusion after two spectra). Collision energies of 10, 20 and 40 eV for collision-induced decomposition were used. The source conditions have been reported elsewhere [15; 17]. The Agilent Profinder B.06 software was used to elaborate the raw mass features (i.e., entities consisting in a combination of raw abundances and isotopic mass spectra). Features were aligned, and the monoisotopic accurate mass was combined with the isotopic profile for the compounds' annotation, thus reaching a level 2 of confidence in annotation (i.e., putatively annotated compounds). The annotation process was done with the database Phenol-Explorer 3.6, with a mass accuracy tolerance set to 5 ppm. Phenolic compounds passing the frequency of the detection thresholds (100% of replications within at least one condition) were classified and then quantitative information was produced using calibration curves (in the range 0.05-500 mg/L) from solutions of single standard phenolic compounds (Extrasynthese; Genay; France). Selected representative compounds were: cyanidin (anthocyanins), quercetin (flavanols and other flavonoids), luteolin (flavones), tyrosol (other lower molecular weight phenolics) and ferulic acid (phenolic acids). Results were expressed as mg phenolic equivalents/g DM.