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This study aims to compare UV-C irradiation and conventional heat treatment to produce pasteurized onion juice used as a meat marinating agent. The process conditions maximizing the inactivation of target microorganism Escherichia coli K-12 were; 0.5 mm sample depth, 30 min irradiation, 7.5 mW/cm2 UV incident intensity for UV-C and, 74.5°C and 12 min for heat treatment. Except pH and non-enzymatic browning index, differences between physicochemical properties of raw, UV-C and heat-treated onion juices were significant. Springiness and chewiness of unmarinated beefsteaks were higher compared to the ones marinated with the fresh and pasteurized onion juice (UV-C and heat). Pasteurization of onion juice (UV-C and heat) did not significantly affect general liking scores compared to beefsteaks marinated in untreated onion juice.

Onion (Allium cepa L.) juice is a marinating agent for meat and fish marination and readily usable sauce for any meal that has onion in its formulation. This study aims to assess the microbiological and physicochemical changes in the onion juice processed by UV-C irradiation (0.5 mm sample depth, 30 min exposure time, 7.5 mW/cm2 UV incident intensity) and conventional heat treatment (74.5°C, 12 min) during its storage. Microbiological results showed processing by UV-C irradiation or heat treatment under optimum conditions extended the microbial shelf-life of untreated onion juice by minimum 6-times. Total colour change of heat-treated samples was lower than that of untreated and UV-C treated samples for 12 weeks. Also, pH, total titratable acidity, total soluble solids content, turbidity, NEBI and total phenolic content were monitored for 12 weeks. The results of this study will form scientific infrastructure for onion juice manufacturers to decide on the processing method with respect to its shelf-life.