Effects of thermal processing on antioxidant, phenolic and anthocyanin levels in blackcurrant juice

Abstract

OF THESIS Effects of Thermal Processing on Antioxidant, Phenolic and Anthocyanin Levels in Blackcurrant Juice By Bridget A. Skahill Thesis Director: Dr. Mohamed M. Rafi Health and Wellness continues to be a major driver for consumers within the current marketplace. Given this climate, superfruits such as blackcurrant (Ribes nigrum) are gaining interest among beverage manufacturers due to their high content of antioxidants and anthocyanins. Blackcurrant juice, while very popular in Europe, is just beginning to gain acceptance in the domestic marketplace. Various thermal processes are required throughout the production of a shelf stable juice product at both the raw material and finished beverage stages. The goal of this research is to evaluate the effect of these thermal processes on the retention of heat sensitive compounds such as phenolics, anthocyanins and overall antioxidants in the final consumer beverage. To this end, bulk samples of 13 brix flash pasteurized and 65 brix concentrated blackcurrant juice were obtained and further processed at beverage scale. The beverage scale processing entailed the three key thermal processes utilized by retail manufacturers: aseptic, hotfill and tunnel pasteurization. The raw material juices and fully processed samples were then analyzed for anthocyanin content, total phenolic