Micro-perforated packaging delays leaf yellowing and maintains flavor of postharvest pak choi (Brassica rapa subsp. chinensis) following low-temperature storage

Abstract The objective of this study was to investigate the effects of micro-perforated packaging on the quality attributes of pak choi (Brassica rapa subsp. chinensis) during shelf life (20 °C) removed after 7 d at 4 °C. Gas composition in macro-perforated control packaging stayed close to air, non-perforated packaging resulted in anoxia, and micro-perforated packaging effectively held high enough O2 level, where 12.5 % O2 and 8.9 % CO2 was modified by 12 micro-perforations of 100 μm in diameter after 3 d of shelf life. Weight loss and yellowing were most serious in the control, and off-odor occurred in non-perforated packaging. Micro-perforated packaging delayed yellowing due to the lowered activities of chlorophyll-degrading enzymes, increased total polyphenol content, enhanced antioxidant capacity, and preserved flavor of pak choi. These results showed that micro-perforated packaging should be recommend for fresh leafy vegetables during shelf life following low-temperature storage, which is commonly utilized in the distribution chain.