Effect of ultrasound, heating and enzymatic pre-treatment on bioactive compounds in juice from Berberis amurensis Rupr.

Abstract

The aim of the study was to assess the influence of ultrasound (frequency 20kHz, amplitude 70%, power 140W for 10min), heating (80°C, 5min) and enzymatic pre-treatment of mash (50°C, Rohapect 10L at a dose of 0.23g/1000g, maceration time 60min) on the yield, the content of phenolic compounds (including anthocyanins), ascorbic acid, and the antioxidative capacity of Berberis amurensis juice. Additionally, the polyphenols profile of this raw material and juices was identified. 25 phenolic compounds were identified in the fruit and 24 in juices. The content of phenolics in the fruit was 636mg/100g. Chlorogenic acid, 4-hydroxybenzoate and quercetin-3-O-glicoside were predominant. The content of anthocyanins in the fruit was 217mg/100gf.w., where peonidin-3-O-glucoside (98%) was predominant. The content of ascorbic acid amounted to 16.60mg/100g. The yield of the barberry juice pressing process ranged from 56% to 60% - there were no differences between the mash treatment methods. The enzymatic and thermal treatment of the mash resulted in the highest content of phenolic compounds in the juice. The sonication resulted in the highest content of anthocyanins, including peonidin-3-O-glucoside, as the main anthocyanin. The thermal treatment of the mash resulted in a lower loss of ascorbic acid than the other methods. The juice from the mash subjected to pectinolysis or heat treatment exhibited the highest antioxidative capacity.