Physicochemical changes in GRAS coated and gamma radiated water chestnut (Trapa bispinosa Roxburg) during ambient storage in different storage structures

The effects of gamma radiation (control, 0.25kGy, 0.50kGy, 0.75kGy, 1.00kGy) and dip treatment of liquid paraffin wax (12%) on the physico-chemical quality of freshly harvested dried water chestnut (Trapa bispinosa Roxburg), packed in glass jar, tin container and low density polyethylene (250 gauge), and the radiation sensitivity of lesser grain borer in gamma radiated samples was analyzed by inoculation of 15 lesser grain borer pest during a period of 6 months at room temperature. The data on the basis of physical properties revealed that weight loss, damage per cent and number of lesser grain borer was found to be 8.93–14.46, 6–24.5 percent and 2–18 borers. The chemical composition ranged from viz; moisture (9.40–10.10), protein (8.82–8.87), fat (0.90–1.00), carbohydrate (76.83–76.87), total ash (3.15–4.03). The effect of gamma radiation and liquid paraffin wax coating on total sugar, reducing sugar, phenol and acidity, and ascorbic acid were from 5.83–5.88, 1.84–1.87, 0.14–0.16, 0.11–0.12 per cent and41.66–50.00mg/100g respectively. Statistical analysis reveals significant difference in physical parameters (weight loss and damage percent) however in case of chemical composition, throughout the storage period a marginal changes was observed in 0, 3 and 6 months. Irradiation had no appreciable effect on chemical parameters. The treatment combination W4R4 (12% liquid paraffin wax and 1.00kGy) stored in tin container was found to be the best and can extend shelf life up to 6 month without losing the quality of stored water chestnut.