Comparative study of quality of cloudy pomegranate juice treated by high hydrostatic pressure and high temperature short time

Inactivation of microorganisms and its kinetic model of high hydrostatic pressure (HHP) processing of cloudy pomegranate juice at different pressures (300 and 400 MPa) and different treatment times (2.5, 5, 10, 15, 20, and 25 mm) were studied. Besides, HHP (400 MPa/5 min) and high temperature short time (HTST) (110 degrees C/8.6 s) treatment were comparatively evaluated by examining their impacts on microorganisms, pH, total soluble solids (TSS), titratable acidity (TA), color, total phenols, anthocyanins, antioxidant capacity and shelf-life characteristics of 90 days at 4 degrees C. The inactivation effect of microorganisms by HHP fitted Weibull model well and HHP at 400 MPa/5 min inactivated microorganisms effectively. The microbial safety was ensured in HHP-treated and HTST-treated sample. A greater retention of the original color, anthocyanins and antioxidant capacity and increased total phenols were observed in HHP-treated samples immediately after processing. During storage, color changed and anthocyanins content, total phenols and the antioxidant activity decreased, where the changes depended on the applied treatments. The pH, TSS and TA did not show significant change immediately after HHP or HTST treatment and during storage. Industrial Relevance: Cloudy pomegranate juice is one of the most popular fruit juice and requires strict processing and storage conditions to keep the safety and quality. Our research presents a fair comparison between HHP and HTST treatment The available data shows the different impacts on cloudy pomegranate juice of HHP and HTST treatment and the changes of quality during storage. This study would provide technical support for commercial application, evaluation and the criteria establishment for commercial production of HHP and HTST treatment in juice industry, and also provide a non-thermal treatment to meet the growing demand from consumers for healthier food products. Crown Copyright (C) 2013 Published by Elsevier Ltd. All rights reserved.