اثر زمان برداشت و خشك كردن طبيعي و مصنوعي پس از برداشت بر قابليت نگهداري سير سفيد Allium sativum L همدان

The effect of harvesting time and drying at natural and artificial conditions on the storability of white garlic (Allium sativum L.) population of Hamedan

Proper drying is essential to successful marketing in regions which cultivated Garlic (Allium sativum L.) and most serious post harvest losses result from improper drying. For this reason, after the cut off irrigation, white garlic population were harvested at three stages. The first stage of harvesting was done after that approximately 70 percent of the top leaves turned yellow, while the second harvesting was began when whole leaves became yellow and eventually the last harvesting was ensued by getting dry, brown leaves which fell over on the field. After harvesting, bulbs dried at natural condition and artificial state at 35, 45 and 550C. Effect of harvesting stage and drying conditions on the garlic shelflife were investigated during 6 months and qualitative and quantitative factors i.e. moisture content, pyruvate, color and texture in addition to weight loss and spoilage were measured bimonthly. The results of two years study showed that after harvesting, there was no significant difference between pyruvate, color and texture contents of cloves. Drying time at natural condition of the first stage of harvesting was longer than artificial drying process time as well as the other harvesting stages. At 55°C some cloves turned yellow, soft and sticky especially at the early stages of harvesting. During the post harvest drying of garlic the moisture content of cloves was relatively constant, while that of the skins and stem rapidly decreased. After curing, moisture contents of the cloves, skins and stems were 64±1, 20±2 and 15±4 percent respectively. Effect of drying on some quality factors showed that at low temperatures, the pyruvate content and color changes decreased. Qualitative and quantitative factors at the end of storage period showed that for harvesting at the first stage, drying at 35°C or natural conditions and at the second stage, drying at 35°C and 45°C or natural conditions were the best.