中文摘要：

本实验研究了不同微波炉烹饪对白萝卜的Vc、风味物质和质构的影响。白萝卜经水浴锅、变频微波炉、非变频微波炉和直喷蒸微波炉烹饪后,以紫外分光光度法测定Vc含量,以质构仪的TPA模式测定其脆性,以气相色谱法测定其风味物质,同时使用扫描电子显微镜观察白萝卜生样和处理样的微观形貌。在实验条件下,Vc、风味物质保留率基本上均呈现随温度升高和保温时间延长而降低的趋势,即65℃〉75℃〉85℃〉95℃。对于质构而言,脆性值随温度升高和保温时间延长而降低,但是部分处理样的脆性值超过相应生样。根据实验结果可知：85℃保温烹饪5 min,水浴、变频、非变频和直喷蒸微波炉的水分保留率分别为：92.76%、90.87%、90.31%、91.86%,微波烹饪比水浴烹饪更容易造成白萝卜水分的丧失;白萝卜在85℃~95℃保温烹饪5 min左右,水分保留率均在90.00%以上,除变频微波炉之外,其他的Vc保留率均超过60.00%;在适当的烹饪温度和时间范围内,非变频微波炉和直喷蒸微波炉烹饪白萝卜的效果比水浴和变频微波炉的较好。

英文摘要：

The effect of different microwave oven cooking methods on vitamin C（Vc）, retention rate of flavor substance, and texture of white radish were studied in this experiment. After white radish samples were cooked in a water bath, an inverter microwave oven, a non-inverter microwave oven, and in a direct injection steam microwave oven, the Vc content, brittleness, and the retention rate of flavor substance were determined by ultraviolet spectrophotometry, texture profile analysis（TPA） by using a texture analyzer, and gas chromatography（GC）, respectively. On the contrary, the morphologies of raw and processed white radish samples were examined using scanning electron microscope（SEM）. Under the experimental conditions, the retention rates of flavor substances and Vc generally showed a downward trend along with the increase in temperature and extended heat-holding time, i.e., 65 ℃ 〉75 ℃ 〉85 ℃〉 95 ℃. Texture analysis showed that the brittleness values decreased along with the increase in temperature and extended heat-holding time. However, the brittleness values of some processed samples were higher than those of the corresponding raw ones. The results obtained showed that after cooking at 85 ℃ for 5 min, the moisture retention rates for water bath, inverter microwave oven, non-inverter microwave oven, and direct injection steam microwave oven were 92.76%, 90.87%, 90.31%, and 91.86%, respectively, and that microwave cooking caused food moisture loss more easily than cooking in a water bath. After cooking at 85 and℃ /or 95 ℃ for about 5 min, the moisture retention rates were above 90.00% for all, and the Vc retention rates were higher than 60.00% for all, except for the sample cooked in the inverter microwave oven. Within suitable cooking temperatures and durations, the effect of using a non-inverter microwave and a direct injection steam microwave oven to cook white radishes were better than when the water bath and inverter microwave were used.