Abstract:
This study aimed to find the optimum combined drying conditions of the hot air drying and microwave drying for garlic slices. The influence factors such as hot air temperature and microwave power were investigated using the drying rate,content of thiosulfinates,sensory quality,
L value,rehydration ratio and comprehensive scores as the indexes. The combined drying conditions were optimized through the L
9(3
3)orthogonal test with hot air temperature,moisture content of conversion point and microwave power as experimental factors. The results showed that the comprehensive scores of garlic slices dried under hot air at 60 ℃ and microwave at 550 W conditions were higher,83.64 and 80.74,respectively. The overall merit was very significantly influenced by hot air temperature and microwave power(
p<0.01)and significantly influenced by the conversion point of moisture content(
p<0.05). The optimum conditions of combined drying with hot air and microwave for garlic slices were 65 ℃ hot air drying to 1.00 g/g moisture content of conversion point and then 550 W microwave drying to 0.18 g/g moisture content. Under the optimum conditions,the drying rate of garlic slices was the fastest,the content of thiosulfinates was the highest to 1.7739 mmol/100 g and comprehensive scores was the highest to 92.21,and the sensory quality was very well,suggesting that hot-air drying followed by microwave drying was a good method and quite suitable for drying garlic slices.