Impact of thermal and thermosonication treatments of amora (Spondius pinnata) juice and prediction of quality changes using artificial neural networks

The impact of thermal and non-thermal treatments on the quality of amora (Spondius pinnata) juice during refrigerated storage (4 +/- 1 degrees C) for 30 days was investigated. Freshly prepared juices from amora fruits were thermosonicated at the frequency of 44 kHz for 30, 45 and 60 min at 40 degrees C and also pasteurised at 90 degrees C for 1 min. Changes in the quality parameters, such as, pH, total soluble solids, titratable acidity, total phenolic contents, total flavonoid contents. Antioxidant activity, ascorbic acid content, browning index, cloud values and microbial populations were checked periodically. The experimental results indicated a significant increase in total phenolic contents, total flavonoid contents, anti-oxidant activity and the sensorial properties of thermosonicated juices during storage their period when compared to fresh and thermally treated amora juices. Maximum reduction in the microbial populations was accomplished after thermal and thermosonication for 60 min treatments. The physicochemical properties of thermosonicated juices exhibited minimal changes in contrast to other samples. The prediction of the quality changes in thermosonicated juices during storage was carried out using an artificial neural network model. From this study thermosonication at 40 degrees C can be recommended as a substitute to thermal processing and it may be employed to amora juice production to decrease the microbial population and improve functional and sensorial properties.(c) 2022 IAgrE. Published by Elsevier Ltd. All rights reserved.