Effects of Packaging Liners on Cooling Rate and Quality Attributes of Table Grape (cv. Regal Seedless)

摘要

Table grapes are commonly packed in multi-layered packages consisting of cardboard carton, plastic liners and carry bag/pouch to maintain product quality along the cold chain. Each liner is characterized by the number and the size of perforations, which influence the environmental conditions around the produce inside the package. This study investigated the effects of different carton liners on the cooling rate and quality attributes of 'Regal Seedless' table grapes. Fruit quality attributes measured include weight loss, stem dehydration and browning, SO_2 injury, decay, berry firmness and colour. Non-perforated liners maintained relative humidity (RH) close to 100% during cold storage and during a 7 day shelf life period, which resulted in delaying the loss of stem quality but significantly (p ≤ 0.05) increasing the incidence of SO_2 injury and berry drop during storage, as compared with perforated liners. Perforated liners improved fruit cooling rates but significantly (p ≤ 0.05) reduced RH. Low RH in perforated liners resulted in significant (p ≤ 0.05) increase in stem dehydration and browning as compared with non-perforated liners. Berry firmness decreased by 78% after 42 days of storage at -0.5℃. Significant (p ≤ 0.05) differences in berry firmness between the different packages were observed only during the first 7 days of storage. Berry colour changed from greenish-yellow to yellowish-green in all types of plastic liner during the storage period. Fruit decay occurred in all packages after a 7 day shelf life, with the highest incidence of decay occurring in liners with less perforation.