Evaluation of UV-C Irradiation Treatments on Microbial Safety, Ascorbic Acid, and Volatile Aromatics Content of Watermelon Beverage

UV-C treatment technology is proposed as a potential alternative to thermal treatments for decontamination of beverages because heat may adversely affect the nutritive value and quality. Effects of UV-C irradiation processing on microbial inactivation, ascorbic acid, and volatile aromatics of watermelon beverage were evaluated using a flow-through UV system. Selected microbial agents Escherichia coli O157:H7 and Bacillus cereus endospores were inactivated by 5.31 ± 0.01 and 6.1 ± 0.01 log CFU mL −1 at UV equivalent fluence levels of 12 and 60 mJ cm −2 , respectively. At UV pasteurization equivalent exposure (40 mJ cm −2 ), 93% ascorbic acid was retained. No significant loss of volatile aromatic aldehydes was noticed at fluence 40 mJ cm −2 . Overall, the results support the UV-C processing as an alternative to traditional thermal processing to preserve quality in conjunction with microbial safety aspects of watermelon beverage.