EFFECT OF GAMMA-IRRADIATION AND EXTENDED STORAGE ON CHEMICAL-QUALITY IN ONION (ALLIUM-CEPA L)

The effects of gamma-irradiation and long-term storage on the chemical quality of the Valenciana sintetica 14 onion variety were determined under warehouse conditions in two sets of bulbs grown consecutively in 1988 and 1989. In both years irradiated and non-irradiated bulbs showed similar behaviour in terms of carbohydrate and ascorbic acid contents throughout the 300 days of storage. It was found that the carbohydrate content significantly decreased in irradiated and non-irradiated samples up to 180 days of storage. The storage time was found not to have a significant effect on the ascorbic acid content of bulbs. The carbohydrate and ascorbic acid contents were found to be higher in the irradiated and non-irradiated bulbs grown in 1988. Neither storage time nor gamma-irradiation nor the specific year significantly affected dry matter or acidity. Gamma-irradiation did not significantly affect flavour strength in terms of total pyruvate content.