Grape peel powder promotes intestinal barrier homeostasis in acute TNBS-colitis: A major role for dietary fiber and fiber-bound polyphenols

Potential of grape byproducts as functional ingredients in baked goods and pasta

“…The DF contents of bread, muffins, and brownies with red and white grape pomace were significantly higher than of the control, increasing with the addition level, bigger changes being reported for those with red pomace (Walker et al, 2014). Maurer et al (2019) reported an amelioration of colitis in rats feed with grape peels, the DF being responsible for the intestinal barrier function reestablishment, whereas the phenolic compounds bounded to fiber fractions contributed to the cecal metabolism restoration, improving the production of beneficial compounds such as cecal shortchain fatty acids with anti-inflammatory and antiproliferative effects on the colonic cells and reducing the activation of the unfolded protein response (Maurer et al, 2019;Yuan, Wang, Chen, Zhu, & Cao, 2016). DF presents many biological functions such as anticancer activity, gastrointestinal activity improvement, antiapoptotic activity, cardiovascular disease prevention, antihypercholesterolemic activity, and anti-hyperglycemia effect (Kurek & Wyrwisz, 2015;Özkaya, Baumgartner, & Özkaya, 2018;Zhu et al, 2014).…”

“…The protein content of grape pomace was reported to be more than 8 g/100 g (Beres et al, 2019;Sousa et al, 2014;Teles et al, 2019;Tseng & Zhao, 2013), whereas some studies (Abdrabba & Hussein, 2015;Maman & Yu, 2019) revealed higher proteins content in grape seeds, depending on the variety. Some studies showed that the protein content of grape peels can vary from 5.3 to 12.7 g/100 g (Deng et al, 2011;Maurer et al, 2019;Mendes, Xavier, Evtuguin, & Lopes, 2013;Mironeasa et al, 2019c), as it is shown in Table 1. The amino acid profiles of grape byproducts depend on the variety (Iuga, Codină, Mironeasa, & Oroian, 2017;Tangolar, Turan, Tangolar, & Ateş, 2019); Iuga, Codină, et al (2017) showed that grape seeds have high contents of glutamic acid, aspartic acid, glycine, and arginine, whereas grape peels are richer in lysine, glutamic acid, aspartic acid, and leucine-both grape seeds and peels proteins qualities being close to those of other cereals and oilseeds like sunflower, safflower, and flaxseeds (Mironeasa, 2017;Secen, 2017;Zhou, Li, Zhang, Bai, & Zhao, 2010).…”

“…The fat content depends also on the grape variety and processing conditions, most of the fat being located in grape seeds (Deng et al, 2011;Maurer et al, 2019;Mendes et al, 2013;Mironeasa et al, 2019c;Tseng & Zhao, 2013) and consisting of about 90% of monounsaturated fatty acids (Sousa et al, 2014). Baydar and Akkurt (2001) found that the oil contents for both red and white pomace seeds are similar with a total average of 16.3% (v/w), approximately 87% being unsaturated, which has more benefices for health as compared to saturated oils.…”

Non-Extractable Polyphenols from Food By-Products: Current Knowledge on Recovery, Characterisation, and Potential Applications

“…Since air drying is a relatively long process, this method is mainly used for low water content by-products, such as grape seeds, blueberry leaves, and black tea leftover. Instead, for high water content by-products, freeze-drying seems the preferred drying technology [20,[57][58][59]. Freeze-drying, also called as lyophilisation, is a drying technique with the highest ability to maintain the product quality (structure, colour, nutritional value, etc.)…”

“…Briefly, the residues after EPPs extraction were hydrolysed with methanol/H 2 SO 4 (90:10 v/v) at 85 • C for 20 h. Then, the content of hydrolysable tannins was determined by analysing the supernatants combined with two times residues washing with distilled water. This method has been extensively used in recent years to determine the NEPs content from fruit peels or pulps [3,55,72,73], rice bran [61], palm kernels [74], and olive pomace [59]. To maximise the efficiency of acid hydrolysis, in 2014, Cheng et al optimised the treatment condition based on a response surface methodology.…”