不同干燥方式下洋葱贮藏生化指标的比较

Comparison of storage biochemical index of onion in different drying methods

利用热风、微波和微波真空加热对黄皮洋葱进行干燥处理,比较了各种干燥方式对洋葱贮藏生化指标的影响。实验表明:洋葱干燥后过氧化物酶活性、细胞色素氧化酶活性为微波真空加热干燥>55℃热风干燥>80℃热风干燥>微波加热干燥;微波干燥和微波真空干燥能极显著提高洋葱中还原型Vc含量,极显著降低洋葱中脱氢Vc含量,微波真空加热干燥能明显提高洋葱白度。

The effects of different drying methods on storage biochemical index of onion were studied when onion was dried by hot air heating,microwave heating and microwave heating with vacuum.The results showed that the peroxidase activity and cytochrome oxidase activity of dry onion were in following order from strong to weak:microwave heating with vacuum,the hot air heating at 55℃,the hot air heating at 80℃and then microwave heating.The con- tent of deoxidized ascorbic acid was increased remarkably and the content of dehydro ascorbic acid was decreased obviously when onion was dried by micro- wave heating and microwave heating with vacuum.And remarkable difference of deoxidized ascorbic acid resulted in remarkable difference of the total con- tent of ascorbic acid between microwave heating and microwave heating with vacuum,The white degree of onion could be improved by microwave heating with vacuum.