Analysis Of Shrimp Flavor And Preparation Of Shrimp Flavoring Base

Palaemon modestus Heller and Macrobra chiumni ponense are the most famous crustacean food in Wuxi. Their flavor compounds were studied and compared with the popular Penaeus chinesis. Shrimp waste was generated from the fishing industry. The abundant waste may pose an environmental polution due to the ease of deterioration. Because of being rich in protein the waste can be extracted useful components and prepared shrimp flavoring base through enzymatic hydrolysis and Maillard reaction methods.Traditional simultaneous distillation extraction (SDE) was used to extract the volatile compounds from Macrobrachium nipponense, Penaeus chinesis and Palaemon modestus Heller. OV1701 capillary column was chosen to separate the volatile compounds among three capillary columns because it showed the best results. A total of 116 volatile flavor compounds were isolated and identified successfully by GC-MS. Alkyl pyrazines and sulfur-containing compounds were most in the three samples. The Solid-phase Microextraction (SPME) extraction method was also tried.The free amino acid compositions, ATP-related compounds and total creatinine content of the three samples were investigated. The most abundant amino acids present were glycine, arginine, alanine ,proline and taurine. These free amino acids were very important to the taste and contributed a lot to the volatile flavor. IMP, GMP, inosine and creatinine may act importantly and synergistically to the desirable taste of shrimp.The operation condition of the enzymatic catalysis using a combination of Flavourzyme and A.S.1398 were optimized by single factor experiment and orthogonal regression experiment. The results indicated that the optimum conditions were: the ratio of the sample to water 1.5:1,reaction temperature 50℃,initial pH 7.0, reaction time 3h and the dose of Flavourzyme 4% and A.S.1398 2% (w/w, Enzyme/Protein). Under such experimental conditions, the degree of hydrolysis (DH) was 22.32% and gave a good taste. Pyrazines were the most in the product .The Maillard reaction was investigated for the enzymatic hydrolysate in order to improve the aroma intensity. The optimum conditions for the Maillard reaction optimized by the single factor experiments were as follows. The ratio of glucose and xylose was 4:1, the ratio of was 1:1. The beginning pH of the system was 7.0 and 30min at 110℃.The Maillard product gave roasted and shrimp-like flavor.