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Most polyphenols are glycosylated, affecting their uptake, metabolism, and biological activity. However, the attached sugar must be removed before absorption and functionality can take place. Yet, despite the biological and chemical implications of polyphenol (de-)glycosylation, most in vitro digestion assays omit the utilization of intestinal brush border α- and/or β-glycosidases to study polyphenol bioaccessibility and deglycosylation. This study investigated the effect of rat small intestine extract (RSIE) as an affordable source of mammalian α- and β-glycosidases in different food matrices: matrix-devoid whole apple extract, whole apple, apple juice, and apple pomace. Using the INFOGEST 2.0 model, transepithelial polyphenol absorption, UHPLC-ESI-QTOF-MS/MS, and the inclusion of RSIE at the 15 U*mL -1 maltase activity reported in the human epithelium, the role of RSIE in polyphenol bioaccessibility and deglycosylation was explored. Moreover, the effect of the plant cell wall (PCW) matrix on the role of RSIE was mechanistically investigated by comparing whole apple (or pomace) with their respective extracts. 36 glycosylated polyphenols were identified, including 33 β-O-glycosides and 3 α-O-glycosides. The content of bioaccessible polyphenol β-O-glycosides and α-O-glycosides was significantly lower (p < 0.001) when RSIE was present, which resulted in a concomitant generation of the aglycone forms (phloretin, quercetin, ferulic acid, caffeic acid and p-coumaric acid). However, the concentration of aglycones was much lower than the reduction in the concentration of glycosylated polyphenols, strongly suggesting that polyphenols bind to RSIE. Matrix-devoid whole apple extract, or pomace extract, exhibited higher polyphenol bioaccessibility than whole apple or pomace, likely due to reduced interactions between polyphenols and the food matrix. Importantly, these differences in bioaccessibility diminished with RSIE, suggesting that RSIE α-glycosidases cleaved α-glucans and disrupted the PCW structure., Competing Interests: 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., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Polyphenol partitioning during mechanical (cold-pressing) and physiological (digestion) extraction at the individual polyphenol and subclass level was investigated. UHPLC-ESI-QTOF-MS/MS analysis yielded a comprehensive identification of 45 polyphenols whose semi-quantification revealed a hierarchical clustering strongly determined by polyphenol structure and their location within the apple tissue. For instance, pomace retained most flavonols and flavanols (degree of polymerization DP 5-7), which were highly hydrophobic, hydroxylated, or large (>434 Da), and more abundant in peel. In vitro digestion UHPLC-ESI-QTOF-MS/MS analysis of whole apple (and its corresponding matrix-free extract) clustered polyphenols into five main groups according to their interaction with plant cell walls (PCWs) during each digestion phase. This grouping was not reproduced in pomace, which exhibited a greater matrix effect than whole apple during oral and gastric digestion. Nevertheless, the interaction between most polyphenol groups, including dihydrochalcones, flavanols (DP 1-4) and hydroxycinnamic acid derivatives, and pomace PCWs was lost during intestinal digestion., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Mario M. Martinez reports financial support was provided by Independent Research Fund Denmark. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

The industrial manufacturing of fruits and vegetables generates approximately 50% by-product waste, causing a negative environmental impact and significant expenses. Nevertheless, fruit and vegetable by-products (FVB) are rich nutrients and extranutritional compounds that contribute to bowel health, weight management, lower blood cholesterol levels and improved control of glycemic and insulin responses. Due to the positive influence of FVB fibers and bioactive compounds during the digestion of glycemic carbohydrates, such as starch, baked goods are ideal food systems to accommodate FVB, since most of them have a high glycemic index. Therefore, this is an area of recent interest with critical environmental, economic and health implications worldwide. However, the utilization of FVB in baked goods leads to the loss of acceptability, in many cases caused by a lack of understanding of the physical structure and composition of FVB and their effects on food quality. The objective of this review is to provide a mechanistic understanding of the impact of the physical structure and composition of FVB on common baked goods and their influence on the nutritional and physical quality of the resulting product. This review will support the use of FVB as ideal ingredients while improving the added value of waste streams. [ABSTRACT FROM AUTHOR]

The most abundant oilseed cakes, soybean, rapeseed/canola, and sunflower, and especially those from cold-pressing, contain meaningful amounts of antinutritional polyphenols that limit their potential as plant protein sources. The objective of this study was to remove polyphenols, and especially sinapic and chrologenic acid derivatives in canola and sunflower, respectively, using pilot-scale extrusion, and without compromising the nutritional and the technological quality of the protein fraction. Extrusion significantly increased the ratio of soluble to insoluble dietary fiber from 0.45 to 0.58 in canola and from 0.19 to 0.31 in sunflower, whereas the opposite was found in soybean (0.52 to 0.36). Canola (67.7 mg GAE/g) and sunflower (58.9 mg GAE/g) exhibited large quantities of polyphenols, which mostly consisted of sinapic and chlorogenic acid derivatives, respectively. Extrusion increased the proportion of free polyphenols and did not significantly reduce the amount of sinapic acid derivatives in canola. On the contrary, extrusion decreased the content of free polyphenols in sunflower by 68%. Generally, the extrusion conditions shown in this study resulted in limited protein denaturation and aggregation and a moderate decrease in β- sheet structures (up to 59%), which led to similar liquid holding capacity and enhanced protein solubility. Extrusion notably increased the gastric protein hydrolysis of soybean cake, but it negligibly affected that of canola and sunflower counterparts, possibly due to the counteracting effect of indigestible quinone-protein adducts. Extrusion is a promising technology to reduce polyphenols meaningfully in certain oilseed cakes while retaining or improving protein quality. • Cold-pressed cakes were rich in antinutritional polyphenols • Extrusion increased the soluble dietary fiber content in canola and sunflower cakes • Extrusion decreased the content of free polyphenols in sunflower by 68% • Extrusion resulted in limited protein aggregation and enhanced solubility • Extrusion is promising to reduce polyphenols while retaining protein quality [ABSTRACT FROM AUTHOR]