Bioavailability and bioactivity of encapsulated phenolics and carotenoids isolated from red pepper waste

Abstract

© 2019 by the authors. In order to deactivate the health properties of bioactive compounds, they need to withstand the effects of food processing, their potential release from the food matrix, and remain bio-accessible in the gastrointestinal tract. Bio-actives from different plants are prone to oxidative degradation, and encapsulation is an effective method in improving their stability. In the present study, red pepper waste (RPW), a by-product of vegetable processing industry, was encapsulated in whey protein using spray and freeze-drying techniques. The aim was to evaluate the effects of in vitro gastrointestinal digestion on the release and bioactivity of encapsulated bio-actives, after each digestion step. The results showed that the release of phenolics and carotenoids, as well as antioxidants, anti-hyperglycemic, and anti-inflammatory activities are influenced by pH and intestinal fluid, with pH 7.5 exhibited at higher levels. There was a rapid initial release of carotenoids from whey protein matrices, while a more gradual increase of phenolics was observed, reaching around 50% for both encapsulates first at 6 h and 37 ◦C, and small intestine conditions. The encapsulation of RPW demonstrated a protective effect against pH changes and enzymatic activities along digestion, and contributed to the increase in bio-accessibility in the gut. Also, the results suggest that encapsulation is an efficient method for valorization of bio-actives from RPW, with improvements in nutrition, color, and bioactive properties.