Comparison of high-pressure processing, ultrasound and heat treatments on the qualities of a gallic acid copigmented blueberry-grape-pineapple-cantaloupe juice blend

A blueberry-grape-pineapple-cantaloupe juice blend was copigmented with gallic acid (GA) firstly and treated by high-pressure processing (HPP) at 550 MPa, 25 degrees C for 5 min, ultrasound (US) at 520 W, 40 degrees C for 10 min, or heat treatment (HT) at 90 degrees C for 3 min to determine their influence on its physicochemical qualities. The shelf lives of HPP-, US- and HT-juice blends were 72, 48 and 88 days, respectively. The total anthocyanins (ACs), ascorbic acid and total phenols content in juice blends treated by HPP, US and HT did not change immediately after treatment or during the first 16 days' storage. However, after the three treatments, the total ACs, ascorbic acid and total phenols content in juice blends decreased in the following order after 16 days: US > HPP > HT. The HPP- and US-treated juices were superior to the HT-treated juices regarding flavour, and in the preservation of more types and relative content of esters and aldehydes. In conclusion, GA improved the total ACs and ascorbic acid stability in the juice, while the flavour of the HPP- and US-treated juices surpasses that of HT-treated juice. Therefore, the HPP treatment was deemed to be more advantageous and had greater market potential for short-term storage.