Effects of ozone washing on quality of green oak lettuce during low temperature storage

Abstract

The effect of ozone washing on green oak lettuce quality during storage at 8°C was investigated. This research was designed by completely randomized design (CRD) with 4 treatments, such as 1) unwash (control), 2) tap water washing, 3) cold water washing (5°C for 5min) and 4) cold ozone water washing (1g/L 5°C for 5 min) (4 replicates). It was found that the lettuce of unwash treatment started browning after storage for 3 days, while the cold ozone water treatment showed browning at 15 days of storage. That treatment showed the slowest and lowest browning score when compared with other treatments. In addition, the cold ozone water of lettuce had significantly the lowest total contaminated microorganisms for 0 and 15 days of storage time. In the part of freshness, color and total consumer acceptance of lettuce for the cold ozone water treatment showed significantly the highest score, followed by cold water, tap water and unwash treatments, respectively. Moreover, the lettuce after washed with cold ozone water reduced weight loss, which had significantly titratable acidity (TA) and total soluble solids (TSS) content when compared with other treatments although storage time for 15 days.