The combined impact of calcium lactate with cysteine pretreatment and perforation-mediated modified atmosphere packaging on quality preservation of fresh-cut 'Romaine' lettuce

摘要

The effect of perforation-mediated modified atmosphere packaging (PM-MAP) in combination with calcium lactate (1.5% CaL) and cysteine (0.1, 0.5% Cys) immersion pretreatments on the quality preservation of fresh-cut 'Ro-maine' lettuce was assessed for 12 days, at 5 and 10 °C. The shredded lettuce was packed in low-density polyethylene films (LDPE, 62 μm thickness), including different perforation numbers of 0 (N-MAP), 20 (20-PM-MAP, Diameter = 64 μm), and 40 (40-PM-MAP, Diameter = 64um) per in square meter. Indices of quality maintenance were investigated. The total microbial counts were below the specified limits for ready-to-eat vegetables (＜ 6 log CFU/g) considering both pretreated 20-PM-MAP and N-MAP samples on day 12. After 8 days, a significant difference (P ＜ 0.05) was observed in the browning index (BI), the total color difference (AE), and the chlorophyll content between N-MAP and 20-PM-MAP samples with better results in 20-PM-MA packages. At 10 °C, the BI in pretreated 20-PM-MAP samples was 32.44% to 58.35% less than N-MAP samples, on the last day of storage. The 20-PM-MAP samples pretreated with 1.5% CaL/0.5% Cys had the highest (P ＜ 0.05) crispness coefficient and water content values. It seems that packaging the pretreated lettuce in 20-PM-MA packages is more effective for maintaining the visual properties (green fresh appearance) of this product, from the 8th to the 12th day of storage.