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Abstract
The effects of microwave (MW) processing and conventional (CV) heating on inactivation of Escherichia coli and Salmonella enterica subsp. enterica, levels of bioactive compounds, antioxidant activity and some health-promoting features of guava juice were investigated. The results showed that MW significantly reduced the time of the process compared to CV heating, so that the time of inactivation of pathogens in MW process was eight times less than the CV method. MW treatment induced a lower reduction in the amounts of total carotenoids, vitamin C, and total phenolics compared to CV heat treatment. MW and CV heating caused losses of 23.99% and 65.52% in DPPH antiradical activity, respectively at the end of the treatment period. In addition, MW-treated samples represented higher enzyme inhibition activities (α-amylase, α-glucosidase, and angiotensin-converting enzyme) compared to CV-treated juices. These findings reveal that MW technology can be used as an alternative to CV heating for processing guava juice in order to ensure microbial safety, reduce process time, save energy, and preserve the essential thermosensitive nutrients.