干燥方式对秋葵中还原型V_C和氧化型V_C含量的影响

Effect of different drying methods on content of ascorbic acid and dehydroascorbic acid in drying process of okra

以秋葵为研究对象,研究热风干燥、微波干燥、真空干燥3种方式对秋葵中还原型VC及氧化型VC含量的影响。结果表明,3种方式对秋葵还原型VC及氧化型VC含量的影响均显著。真空干燥时还原型VC保存率最高,为93.62%,其次是微波干燥,为78.05%,热风干燥还原型VC保存率最低,为59.73%;但热风干燥氧化型VC保存率最高,为120.91%,其次是微波干燥,为111.39%,相反,真空干燥的氧化型VC保存率最低,为108.52%。这说明真空干燥可以隔绝氧气,从而抑制VC的氧化,而热风干燥则使一部分还原型VC与氧气接触而被氧化为氧化型VC。

Vacuum drying, hot air drying and microwave drying were taken as experimental factors to study the preserving rate of ascorbic acid and dehydroascorbic acid of okra. The results showed that all of the three factors significantly influence the preserving rate of ascorbic acid and dehydroascorbic acid of okra. The preserving rate of ascorbic acid is highest under the condition of vacuum drying, of 93. 62%. Then is the microwave dying, of 78.05%. It is lowest under the con- dition of hot air drying, of 59.73%. While the preserving rate of de- hydroascorbic acid is highest under the condition of hot air drying, of 120.91%. Then is the microwave dying, of 111.39%. On the contra- ry, the preserving rate of dehydroascorbic acid is lowest under the condition of vacuum drying. It showed that the vacuum dryer can cut off oxygen, reduce the contact of vitamin C with oxygen, and de- crease the oxidation of vitamin C. While the hot air drying make partof the ascorbic acid be oxidation to become dehydroascorbic acid.