Identification Of Toona Sinensis Characteristic Aroma And The Change During The Processing

Toona sinensis can stimulate people's appetite and bring people the joy of food because of its unique flavor, loved by vast number of consumers over hundreds of years. This research studies the chemical composition of the volatile compounds of Toona sinensis through GC-MS and GC-O technology and explores the chemical basis of the characteristic aroma of Toona sinensis,by preparing samples of Toona sinensis at different growth stages and through different pre-treatment methods. The results of this research are as follows:1. The volatile compounds under different pre-treatment conditions and in different toon materials differ a lot. The Headspace Solid-Phase Microextraction method is suitable for the analysis of trace volatiles and is more suitable for the analysis of heat-sensitive volatile compounds than other methods such as Synchronous Distillation and Extraction method.2. The characteristic flavor substances of Toona sinensis is similar to the Allium plants in the aspect of chemical composition, but the structure is different. The special flavor of Toona sinensis is caused by the propenyl disulfide produced by oxidation of propenyl mercaptan formed by the action of ?-glutamine- (S-propenyl) -cysteine dipeptide, while the special irritant odor of onion and garlic is caused by allyl thioether-induced substances.3. Toona sinensis's characteristic volatile compounds Allyl mercaptan can produce 2-mercapto-3, 4-dimethyl-2, 3-dihydrothiophene after about 80 degrees temperature heating and tastes like steamed toon. After long time of heating, Toona sinensis will continue to produce 3,4-dimethyl thiophene and lose the unique aroma and flavor.4. After blanching, pickling and processing, Toona sinensis's aroma will be greatly lost. To maintain a relatively low temperature during transportation, storage and processing is an important measure to maintain Toona sinensis's unique flavor.Sulfur-containing volatile organic compounds (VOCs) are important contributors to the special flavor of Toona sinensis. Its content and type have important influence on the flavor characteristics of Toona sinensis. How to reduce the loss of sulfur volatiles is the key to maintain the unique flavor of Toona sinensis.