Effect of Different Perforations in Polyethylene Films on Quality of Head Lettuce after Transcontinental Shipment

Abstract

Abstract The effects of different perforations in polyethylene (PE) films used as individual wraps on the quality of iceberg lettuce (Lactuca sativa L.) were evaluated after cross-country shipment from California to Maryland, and after shipment plus storage and holding periods. Butt discoloration was more severe in the naked lettuce than in the PE packaged heads immediately after the transcontinental shipment, but this difference was not as evident after 3 days of holding at 15°C or after 2 weeks of storage at 3°. Number of discolored ribs was consistently lower throughout transportation, storage, and holding periods with lettuce packaged with 0.032 mm PE with 285 perforations/cm2 or packaged with 0.025 mm PE with 112 perforations/cm2 than with lettuce of other treatments. Lettuce packaged in 0.013 mm PE with 10 mm slits had the least weight loss among all the treatments after shipping plus 2 weeks of storage at 3°. However, the decay was more severe in this treatment than in those packaged with perforated PE films. Russet spotting occurred in all the treatments after storage and holding following shipment, but the severity was not associated with packaging treatments. More heads remained salable after 2 weeks at 3° plus 3 days at 15° following shipment in the treatments packaged with perforated PE films than in other treatments, primarily because of less decay and fewer discolored ribs.