Investigating the effects of food matrix and food components on bioaccessibility of pomegranate (Punica granatum) phenolics and anthocyanins using an in-vitro gastrointestinal digestion model

Abstract

Effects of food matrix and individual food components on potential bioaccessibility of pomegranate were investigated by means of simulating in vitro gastrointestinal (GI) digestion. The foodstuffs (sunflower oil, skim milk, cooked lean meat, bread, skim yogurt, probiotic yogurt, apple, lemon, honey, soy milk, cream, and soybean) and the food components (gluten, casein, isolated meat protein, lactose, fructose, galactose, glucose, salt, ascorbic acid, starch, cooked starch, tocopherol, linoleic acid, cellulose, citric acid and pectin) were codigested with pomegranate in model systems to better understand matrix effects. Total phenolic content (TPC) and total anthocyanin content (TAC) were determined by spectrophotometric methods and major phenolics/anthocyanins were analyzed by RP-HPLC/PDA detection both before and after in vitro GI digestion at post gastric (PG), dialyzable (IN) and non-dialyzable (OUT) fractions. Phenolics of pomegranate were found to be stable during gastric conditions (115%), with 25% loss in pancreatic digestion, available (14%) in IN. Although preserved (89%) in PG, anthocyanins were lost in pancreatic digestion (38%), but still available (12%) in IN. Milk, bread, yogurt, probiotic yogurt, lactose, starch, cellulose, salt, citric acid or tocopherol codigestion with pomegranate decreased TPC for all fractions. Proteins affected losses in PG and OUT fractions. Carbohydrates such as starch, lactose, glucose and pectin appeared to affect the loss of phenolics and exerted 2-fold decreases in serum fraction (IN). For TAC, only meat, soymilk or cream codigestion with pomegranate resulted in IN losses. Proteins did not significantly affect TAC in IN, but were inhibitory in PG. However, carbohydrates and fatty acids significantly increased TAC in IN. Generally cyanidins were found to be more stable in food matrices and pancreatic conditions than other anthocyanins.

Black carrot pomace as a source of polyphenols for enhancing the nutritional value of cake: An in vitro digestion study with a standardized static model

“…After simulated intestinal digestion, significantly lower amounts of chlorogenic acid were found compared to simulated gastric digestion (74e85%) (p < 0.05), whereas neither neochlorogenic acid nor caffeic acid was detected. Previous studies also reported dramatic decreases of phenolic acids during in vitro digestion (Celep, Charehsaz, Akyuz, Acar, & Yesilada, 2015;Sengul, Surek, & Nilufer-Erdil, 2014). These reductions in phenolic acids could be associated with changes in pH and the presence of bile salts, which may result in the formation of precipitate (Chethan & Malleshi, 2007).…”

Application of in vitro gastrointestinal digestion and colonic fermentation models to pomegranate products (juice, pulp and peel extract) to study the stability and catabolism of phenolic compounds

“…Considering our results and the low degree of ellagitannin hydrolysis at pH 3 observed by Tuominen and Sundman (2013), the extra amount of free and glycosylated ellagic acid recovered could be explained by the sum of both: ellagitannins degradation and the release of ellagic acid from the food matrix during in vitro gastric digestion. Accordingly, higher recovery of total phenolic compounds was observed after gastric digestion of pomegranate extract (Sengul, Surek, & Nilufer-Erdil, 2014). In another study, a slight modification in total phenolic content was noticed after the acidic incubation of a wild chokeberry commercial juice (Bermúdez-Soto, Tomás-Barberaán, & García-Conesa, 2007).…”

Stability of the phenolic compounds and antioxidant capacity of five fruit (apple, orange, grape, pomelo and kiwi) juices during in vitro‐simulated gastrointestinal digestion

“…Apple contains an abundance of fibres (de Lima et al, 2014) which hinders the release of phenolic compounds from the fruit pulp, and after pepsin hydrolysation during the gastric digestion, most of the bound phenolic compounds became free and were detected by Folin-Ciocalteu method. exposed to acid conditions (Sengul et al, 2014), meaning the polyphenol compounds could not be detected using the Folin-Ciocalteu method. In addition, Folin-Ciocalteu reagent does not specifically react with phenolic compounds and can also be reduced by other substances including sugars, amines, small peptides hydrolysed by pepsin and organic acid, thus leading to an overestimation of the phenolic content in samples (Oliveira & Pintado, 2015;Mokrani et al, 2016).…”