Abstract
Curing and long-term storage are essential postharvest treatments for the year-round shipping of garlic bulbs. We examined the postharvest conditions that induce concavities on the scales of long-term-stored garlic bulbs using ‘Fukuchi White’, a major cultivar in Japan. Bulbs were cured by a tempering method which consisted of heating at about 34°C during the day and nonheating at night under forced ventilation, and were stored at -3, -2, and -1°C under standard and low-humidity regimes for a maximum of 10 months. Some bulbs stored at -3°C had concavities on the scales, but few bulbs stored at -2 and -1°C had concavities regardless of the storage humidity. Bulbs were cured by continuous heating at 33°C or by the tempering method, and were stored at -3, -2, and 0°C for a maximum of 8 months. The mean temperature during tempering was about 30°C. After curing by continuous heating at 33°C, most of the bulbs stored at -3, -2, and 0°C had concavities, but few bulbs stored at -2 and 0°C after curing by tempering had concavities. Severe concavities were observed on the bulbs stored at -2 and -3°C after curing by continuous heating at 33°C. These results suggest that curing at a high temperature and storage at a low temperature induce the occurrence of concavities, and that the curing condition markedly affects the occurrence of concavities when bulbs are stored at -2°C, which is the current storage temperature used for the year-round shipping of garlic bulbs in Aomori Prefecture. This method of curing by tempering combined with storage at -2°C may provide high-quality garlic bulbs throughout the year.
