Lactic Acid and Ultraviolet-C as Sanitizer for Preserving Quality of Minimally Processed Romaine Lettuce

A comparative study on different disinfection methods on the quality of minimally processed romaine lettuce is presented. The lettuce was processed in a clean room through the following steps: reception, cutting, washing, draining, rinsing, centrifugation and packaging. The processed lettuce was packaged at 4C in sealed polypropylene bags using passive modified atmosphere. Sensory attributes (general appearance, texture, color and browning), headspace gas composition, bioactive compounds (antioxidant activity, chlorophylls and vitamin C) and microbial counts were monitored. Lactic acid (2.5g/L) and the use of ultraviolet-C radiation in the washing water could be used as an effective sanitizer to reduce spoilage bacterial growth. Fresh-cut romaine lettuce was not adversely affected by the combined treatment and maintains all sensory, functional and microbial quality during a 9-day storage period at 4C. Practical Applications The information provided in this study shows that the use of ultraviolet-C radiation in the water used for washing could be a suitable disinfection method for minimally processed products and an alternative technique for minimizing water consumption in food industry.