Comparing quality changes of cupped strawberry treated by high hydrostatic pressure and thermal processing during storage

Abstract High hydrostatic pressure (HHP) and thermal processing of strawberry in ethylene vinyl alcohol copolymer cups were evaluated by examining their impacts on microorganism survival and growth, texture, nutritional properties (total phenols, total anthocyanins and antioxidant capacity) and color during 45 days of storage at 4 and 25 °C. During storage, total aerobic bacteria and yeasts and molds were not detected in all treated samples except for those HHP-treated and stored at 25 °C (3.08 and 2.58 log 10  CFU/g at day 45, respectively). There was a reduction in hardness, total phenols, total anthocyanins and antioxidant capacity of flesh, being more striking in samples stored at 25 °C and thermal processing treated samples, and an increase in viscosity, total phenols, total anthocyanins and antioxidant capacity of syrup during storage. Moreover, a significant decrease in the total level of nutritional properties in cupped strawberry (combined flesh and syrup) was observed during storage. All samples showed noticeable color changes, and Δ E values significantly increased during storage. Samples treated by HHP and stored at 4 °C showed higher hardness, total phenols, total anthocyanins and antioxidant capacity and better color than samples treated by thermal processing and stored at 25 °C, indicating that HHP processing and lower storage temperature were very useful tool in preserving the quality of cupped strawberry.