Effect of irradiation and storage on physico-chemical characteristics of garlic

Garlic bulbs (cv. G.S.I.) were irradiated at 0.05, 0.10, 0.15 or 0.20 kGy using ⁶⁰Co and stored in wooden crates for 4 months at ambient temperature (20-37°C, 50-80% RH) or low temperature (10°, 80-90% RH). Samples were monitored for sprouting, rot and weight loss. Consumer acceptability and acid value were determined throughout storage. Sprouting was apparent in control (non-irradiated) samples after 4 and 10 weeks' storage at low and ambient temperature, respectively, and reached 100 and 69% after 16 weeks' storage at low and ambient temperature, respectively. Irradiation inhibited sprouting at both temperatures. Percentage decay [unspecified] was lower in irradiated samples than in controls, which showed 31.7% and 52.9% decay, respectively, after 16 weeks' storage at ambient and low temperature. Weight loss increased from 0.2 to 28.3% and from 0.3 to 31.5% in control samples at low and ambient temperature, respectively, between 2 and 16 weeks' storage. Weight loss was less in irradiated samples. Sensory tests showed that irradiated samples retained colour, texture and odour compared with controls. There was a gradual and significant increase (from 0.448 to 2.246 mg KOH/100 g edible portion of sample) in the acid value of controls during storage. Lower doses of irradiation and storage temperature had an irregular effect on the acid value but the highest dose increased the acid value. It was concluded that irradiation had no deleterious effects on the storage properties of garlic and that a dose of 0.05 kGy could be considered cost-effective. (author)