Effects of Drying and Blanching on the Quality of Toona Sinensis
ZHAO Ming-ye et al(College of Food Science and Nutritional Engineering,China Agricultural University,Beijing 100083)
[Objective] To explore the best Toona sinensis processing technology.[Method] The Toona sinensis was treated by hot wind drying,freeze drying and blanching,and the contents of ascorbic acid,total phenolics and nitrite were determined respectively before and after the treatment to be a standard to evaluate the influence of different processing methods on the quality of Toona sinensis.[Result] Both drying and blanching produced certain impact on the contents of all three components,among which the content of ascorbic acid was slightly influenced by vacuum freeze drying and short-time blanching,but greatly affected by long-time blanching and hot wind drying;the loss rate of phenolics was above 60% when the hot wind drying,freeze drying and blanching lasted for more than 5 min,white it experienced little change under short-time blanching;hot wind drying and blanching may greatly reduce the content of nitrite,however,the vacuum freezing drying even improved the content,which would produce adverse impact on food safety.[Conclusion] Short-time blanching is the best method to process Toona sinensis,it can effectively reduce its content of nitrite and retain the nutrients.