ABSTRACT

In the present work, the effect of thermal (pasteurization) and nonthermal (thermosonication) treatments on the variations in physico-chemical, antioxidant activity, total phenols, total flavonoids, microbial populations, and sensory attributes of pomelo juice was studied. In thermosonication, processing parameters like treatment temperatures (30, 40, and 50 ± 2°C), treatment time (15, 30, 45, and 60 min), and sonication frequencies (33 and 44 kHz) were varied. TSS and TA of thermosonicated samples was not varied in comparison with control samples and minor differences in pH were observed. Significant improvements in DPPH activity, total phenols, and flavonoids were observed in both sonication frequencies and the results significantly varied as the treatment temperature was increased. From the research study, it can be inferred that juice samples processed at 50°C in the sonication frequency of 44 kHz produced maximum levels of total phenols, flavonoids, and DPPH activity.

摘要

在目前的工作中，研究了热（巴氏杀菌）和非热（热超声）处理对柚子汁的理化，抗氧化活性，总酚，总黄酮，微生物种群和感官属性变化的影响。在热超声处理中，处理参数（例如处理温度（30、40和50±2°C），处理时间（15、30、45和60分钟）和超声处理频率（33和44 kHz））有所变化。与对照样品相比，热超声处理的样品的TSS和TA不变，并且观察到pH值的微小差异。在两个超声处理频率下均观察到DPPH活性，总酚和类黄酮的显着改善，并且结果随着处理温度的升高而显着变化。根据研究，