Investigation of the effects of non-thermal, combined and thermal treatments on the physicochemical parameters of pomegranate (Punica granatum L.) Juice

Abstract

The aim of this study is to investigate the change in microbiological, physicochemical and sensory properties of freshly-squeezed pomegranate juice using ultrasound and/or natamycin as an alternative to pasteurization. Samples were pasteurized (80 ℃, 2 min), sonicated (60 % amplitude, 26 KHz, 80 W, 5 min), treated with natamycin (12.5 ppm) and stored at 4 ℃ for one month. Pasteurized pomegranate juice was not significantly changed in terms of pH, Brix, titratable acidity and total phenolic (μg gallic acid equivalent. mL_1) values compared to the treated samples (p > 0.05). During storage, ultrasound-processed pomegranate juice retained more than 90 % total monomeric anthocyanins. Microbial values showed a reduction in load at a level acceptable for the general quality parameters. In the sensory analysis, the general evaluation was accepted as ultrasound and/or natamycin. This study emphasizes the potential application of ultrasound and/ or natamycin to increase the functional value of pomegranate juice.