β-glucan and aronia (Aronia melanocarpa) phenolics: interactions during in vitro simulated gastrointestinal digestion and adsorption

Interactions between phenolics and dietary fibers, such as β-glucan, are important for the bioactivities of phenolics. However, interactions between aronia phenolics and β-glucan in the digestion process, both promoted for their health benefits, have not been studied. The aim was to study the interactions between aronia phenolics and β-glucan in an in vitro simulated digestion and in the adsorption process. After extracting aronia phenolics with chemically- and enzymatically-assisted extraction, and characterizing the phenolics, the aronia extract was subjected to simulated oral, gastric, and intestinal digestion without or with β-glucan. Flavonol release increased throughout oral, gastric, and intestinal digestion, while the recovery of phenolic acids and anthocyanins after an increase in the gastric phase, decreased in the intestinal phase. β-Glucan entrapped phenolics, lowering the quantities of recovered phenolics. It also adsorbed aronia phenolics at pH 1.5, 3.0, and 7.0. In comparison to 15 and 30 mg/L concentrations of β-glucan, a solution with the lower concentration (15 mg/L) allowed for the entrapment of the higher quantity of phenolics and had high adsorption capacity. Entrapment of aronia phenolics by β-glucan is important for the bioaccessibility and concentration of phenolics that reach the lower parts of the digestive tract which depends on β-glucan concentration.