Studies on sprout inhibition of potatoes and onions and shelf-life extension of dates in Iraq

Abstract

Small scale experiments were carried out with onions and potatoes to examine the effect of gamma irradiation (3 – 20 krad) on sprout inhibition under different storage conditions. Higher doses (15 and 20 krad) caused some physical damage to potatoes stored in an incubator at 4 – 10°C and 40 – 70% relative humidity. However, this damage was more apparent in the 20 krad treatment. This damage was also observed when potatoes have been stored at room temperature (17 – 38°C). Sprouting was 100% in the control and appeared after 30 – 60 days storage. The best results obtained when a dose of 10 – 12 krad was used. Studies on onions irradiated and stored at room temperature (15 – 30°C) for ten months showed that 6 – 9 krad gave the best results, extending the storage for 10 months. No sprouting could be detected throughout the storage period. At the lower dose 3 krad, sprouting and spoilage were detected and reached 100% in the control. Shelf - life and organoleptic study was done on four varieties of Iraqi dates at different stages of development. The results showed that the eating quality of fresh dates was not affected significantly by irradiation up to 270 krad and the duration of softening process (after - ripening) of dates was prolonged by low doses of 10 – 90 krad in the majority of the experimental batches. A dose of 270 krad initiated the softening but did not change the time period of after - ripening. The microbiological spoilage of dates was not affected by irradiation.