Enhancement of fruit quality of table grapes ( Vitis vinifera L.) cv. “Perlette” by postharvest treatment of various GRAS chemicals

摘要

Being a non-climacteric fruit, table grape face huge postharvest losses. Some adverse effects of chemicals used for maintaining postharvest quality of table grapes necessitated the find for some safe and natural chemical to replace those uncertain ones like sulfur dioxide. Present study was conducted to evaluate the effects of various GRAS (Generally Recognize as Safe) chemicals on postharvest quality of table grapes cv. “Perlette” during 28 days of storage at 1 ± 1 o C and 90-95 RH. Different concentrations of GRAS chemicals were applied i.e. ethanol (30%, 40%, 50%), potassium metabisulfite (50ppm, 100ppm, 150ppm), egg yolk oil (2%, 3%, 4%) and hot water dip at 55 o C (3 min, 5 min, 8 min). After every week, three replicates of each treatment were evaluated for weight loss, disease incidence, fruit shatter, color, pH, titratable acidity, sugars, ascorbic acid and total soluble solid contents. Sensory analysis was done at the end of cold storage to check the organoleptic acceptability of the fruit for appearance, sweetness, taste, crispiness, aroma and flavor. Findings showed that all treatments significantly (p0.05) reduced postharvest weight loss, fruit color, disease incidence, fruit drop and maintained titratable acidity, ascorbic acid and total soluble solid content throughout the storage as compared to control except egg yolk oil treatments. GRAS chemicals did not have any significant effect on fruit juice, sugar contents and pH value.