Characterization of Volatile Compounds in Grass Carp(Ctenopharyngodon idellus)Soup Cooked Using a Traditional Chinese Method by GC-MS

Fish has long been considered as an available source of high-quality protein in human diet. Grass carp (Ctenopharyngodon idellus) soup, produced with a traditional Chinese method, is one of the most favorite Chinese foods due to its pleasant smell and favorable test. Volatiles in grass carp soup produced with the method were investigated in this study. The volatiles were extracted with simultaneous distillation extraction (SDE) and solid phase micro-extraction (SPME) and analyzed by GC–MS. SDE was more efficient than SPME in extracting volatiles from grass carp soup. Combination the two methods, a total of 113 compounds, including 20 aldehydes, 8 ketones, 30 terpenes, 2 pyrazines, 6 sulfur compounds, 4 acids, 4 esters and 15 other compounds, were identified. Terpenes and aldehydes were the main volatile compounds in grass carp soup. Terpenes and aldehydes together with other kind of volatiles endow the grass carp soup with the favorite flavor. Practical Applications Grass carp (Ctenopharyngodon idellus), one of the "four major Chinese carps," is one of the most important freshwater fish species in China and the world. Boiling with water, garlic and ginger after pan frying with oil is the most common traditional Chinese method to process grass carp. This study first revealed the volatile compounds in grass carp soup prepared by this method with GC–MS combined with AMDIS and LRT. The results are useful to help to understand the flavor smell of fish products, develop fish products and food additives with the traditional Chinese cooking method and promote the application of grass carp even freshwater fish in food industry.