Effect of gamma-irradiation in combination preservation technique for stabilizing high moisture spice based vegetables.

摘要

Combination preservation technique was adopted to stabilize spice-based high moisture (60-70%) knol-khol (Brassica oleracea var. caulocarpa) and cauliflower. The process comprised of additives including 4% sodium chloride to keep water activity (aw) in the range 0.92-0.95, 0.5%, citric acid to reduce pH<4.5 and potassium metabisulphite as anti-browning agent. The products were packed in polypropylene pouches and subjected to 3, 5 and 8 kGy irradiation doses. The storage studies at ambient temperature revealed that the products were microbiologically stable while the browning intensified at higher dosages and the products became softer after 4 months of storage. The commercial spices showed the presence of coliforms and Aspergillus flavus in the dehydrated powder before irradiation. Irradiation in addition to acid and salt infusion treatments reduced the microbial counts from an initial value of 104 to 101 cfu/g and A. flavus was absent. It was concluded that irradiation at 5 kGy was useful as one of the preservative factors in stabilizing high moisture spice based knol-khol and cauliflower products for 4 months at ambient temperature..