MSc

The present study titled “Shrink wrap packaging of selected tropical fruits” was carried out in the Department of Processing Technology, College of Horticulture, Vellanikkara during 2015-2016. The objective was to extend shelf life and to maintain quality of mango, banana and pineapple during storage. The technique of shrink wrap packaging was adopted in three tropical fruits viz., mango, banana and pineapple. Each experiment consisted of 7 treatments wherein shrink wrap packaged fruits along with the unwrapped (control) samples were stored under ambient conditions. Observations on shelf life and PLW (physiological loss in weight) were recorded at an interval of three days and the biochemical characteristics were
analysed at weekly intervals.Mature fruits of mango variety Prior, free of damage and bruises, were washed in plain tap water followed by surface sanitization with 100ppm chlorine for 15 minutes. The chlorinated fruits were spread out on blotting paper to remove excess surface moisture. Surface dried fruits were subjected to two forms of shrink wrapping i.e, individual fruit wrap and wrapping of 4-5 fruits in areca plates with polyolefin film of three densities viz., 15, 19 and 25 μ. Individually shrink wrapped mangoes in 25 μ polyolefin film had the longest shelf life (18 days) and the shrink wrapped fruits
in areca plates with 19 μ polyolefin film had the shortest shelf life (8 days).An increasing trend in the PLW, TSS, total carotenoids, reducing, non- reducing and total sugars were noticed during storage whereas titratable acidity and vitamin C
decreased. Individual shrink wrapping of mangoes with 25 μ polyolefin film was superior among all treatments with regard to quality retention. Banana, cv. Grand Naine was selected for shrink wrap packaging. Desapped banana hands were chlorinated and shrink wrapped with polyolefin film of three
densities viz., 15, 19 and 25μ. Half of the shrink wrapped hands were further master packed in CFB boxes. All the shrink wrapped samples along with unwrapped (control) fruits were stored at ambient temperature. Unwrapped banana hands had the longest shelf life (7 days) as compared to shrink wrapped banana (4 to 5 days). Condensation of moisture inside the film resulted in microbial growth on the surface of banana hands and thus adversely affected the shelf life of samples. Retention of
biochemical constituents was better in shrink wrapped fruits than the unwrapped ones. Off flavour was observed on the shrink wrapped banana hands during storage. Firm, ripe fruits of pineapple cv. Mauritius were cleaned dry, followed by
removal of crown from these fruits. The cleaned fruits were shrink wrapped with polyolefin film of three densities. Half of the shrink wrapped fruits were enclosed in master packs of CFB boxes. The packaged fruits, along with the control samples were
stored at ambient temperature. Individually shrink wrapped fruits with 25μ polyolefin film had longest shelf life (14- 16 days) and was the best treatment with regard to the retention of biochemical attributes PLW, TSS, reducing, non- reducing and total sugars increased during storage while titratable acidity and vitamin C decreased. The results of the present investigation revealed that individual shrink wrapping of mango and pineapple was superior with regard to shelf life and quality characteristics. Shrink wrap packaging was found ineffective in prolonging shelf life of banana under ambient conditions of storage. Polyolefin film of 25μ thickness was better as compared to 15 and 19μ thick films.