Cinética de degradação térmica de antocianinas e seu impacto na cor e na capacidade antioxidante in vitro em frutas vermelhas

Abstract

The berries have been a subject of several studies due to the high content of phenolic compounds and high antioxidant capacity in its composition, an important protective effect against degenerative diseases. The objective of this study was to evaluate the effect of thermal treatment on bioactive purees of blackberry, cherry, raspberry and strawberry compounds. First, these fruits have been subjected to heat treatment for 30, 60, 90, 120 minutes at a fixed temperature of 90°C. In the second step, the fruits were subjected to a heat treatment for 50, 70, 90 and 100ºC, with a residence time of 20 minutes. Shortly thereafter, were assessed the bioactivity of the fruits studied. Tests antioxidants, anthocyanins and visual color were performed. The degradation of anthocyanins in puree blackberry, cherry, raspberry and strawberry combined with heat treatment variation of processing time, have been investigated and described adequately by a first order model. The reaction rate constants were obtained under different conditions and showed that the degradation of anthocyanins is enhanced by increased time at a fixed temperature of 90°C. Integrating the effect of the dynamic conditions of temperature and time that are valid for practical reasons, it becomes possible to predict the effect of the process on the concentration of anthocyanins in berries purees. The preservation of these bioactive compounds is very important because in addition to providing numerous health benefits, can be used as natural dyes, satisfying consumers who are increasingly looking for healthy foods.