Encapsulated bioactive compounds from a winemaking byproduct for its application as functional ingredient in yogurt

Abstract

Tannat skin from grape pomace is a sustainable source of bioactive compounds and dietary fiber. In previous studies we have seen that it has antioxidant, antidiabetic, anti-obesity and anti-inflammatory activity, with the potential to prevent the development of chronic diseases. In this work, the encapsulation of bioactive compounds of an ethanolic extract derived from Tannat grape skin by microparticles of whey protein isolate (without and with enzymatic hydrolysis) and inulin (3:1) is proposed for its application in yogurt as a potential functional food. Spray drying encapsulation was carried out using a tabletop spray dryer (inlet air temperature: 100-140°C, Flow: 600 L/h). The encapsulation efficiency was higher for the encapsulant without hydrolysis (29.7%). Total polyphenol content was determined by Folin-Ciocalteau, and the antioxidant capacity by ABTS and ORAC-FL, obtaining a polyphenols content and antioxidant capacity increase with the addition of extract:encapsulant (1:1) (p<0.05). The microparticles were incorporated into the yogurt, characterizing it by color, and observing a significant increase (p<0.05) of antioxidant capacity by ORAC-FL. In conclusion, spray drying is a suitable methodology for encapsulating Tannat grape skin extract for its application in yogurts as a natural colorant and antioxidant ingredient.