High hydrostatic pressure processing of fresh juice and a fermented beverage of black cherry (Prunus serotina)

The aim of this study was to evaluate the effect of high hydrostatic pressures (HHP) (200 MPa for 10 min, 400 MPa for 10 min, and 600 MPa for 5 min) and VAT pasteurization (60 °C for 30 min) on the microbiological, antioxidant and sensory characteristics of fresh juice and a fermented beverage of black cherry (Prunus serotina) stored for 49 days at 4 ± 1 °C. The HHP processing was effective to reduce the microbial load before storage and during the storage of the fermented beverages; however, for the reduction of the microbial load in fresh juice, a minimum pressure of 600 MPa for 5 min was necessary. At day 0, a reduction of 4.10 logarithmic cycles was achieved in samples processed by HHP and VAT pasteurization. The processed samples showed significant changes (p ≤ 0.05) in their color characteristics. All fermented beverages of black cherry had lower quantities of antioxidant activity, total phenols, flavonoids and anthocyanins. The highest antioxidant characteristics were observed in sample of black cherry processed at 600 MPa for 5 min. The black cherry VAT processed samples were the least sensorially accepted. A treatment of 600 MPa for 5 min could be enough to obtain a microbiologically safe fermented black cherry beverage stable for 49 days having similar antioxidant characteristics as those of fresh juice.