The Effect of Film Wrapping and Nitrogen Flushing of Produce Atmosphere on the Storage Quality of Lettuce

Freshly harvested lettuces of the iceberg variety were used after vacuum cooling in these trials on storability at 5, 15 and 220. Five treatments were observed; four of them consisted of wrapping the lettuces with 4 different types of polymeric films. The 5th treatment consisted of placing some of the lettuces previously wrapped with one of the films into polyethylene bags, then flushing each bag with nitrogen gas for 2 min and sealed with a heat sealer. The samples were stored at 5, 15 and 22 C for 21 days and assessed for weight loss and quality. All the lettuces stored at 5 C retained their quality for 21 days. Nitrogen flushing gave best results with respect to weight loss and overall quality. Lettuces stored at 15 and 22 C spoiled rapidly and 50% or more were considered unsalable after 12 and 9 days, respectively.