| Penaeus chinensis is a popular and important export product of china. Generally, Penaeus chinensis was used as shrimp meat for sale and many shrimp waste was produced on the process of production. The waste material contains much water and fatty acid, which makes them easily perishable and pollute environment. In this paper, we used waste material as raw material and developed some relevant studies. The volatile and sensory compounds of Penaeus chinensis waste were studied. The shrimp flavouring was prepared based through enzymatic hydrolysis and Maillard reaction methods. The major results obtained in this study were as follows:Solid phase micro-extraction method(SPME) was used to extract the volatile compounds from Penaeus chinensis waste. The effect of extraction head(CAR/PDMS, PA, PDMS/DVB), extraction temperature, extraction time and desorption duration on the extraction of Penaeus chinensis waste was also investigated. The results showed that the most kind of volatile compounds and the highest total area were obtained under optimized condition(extract head CAR/PDMS, extraction temperature60℃, desorption duration3min). A total of43volatile compounds were isolated and identified by gas chromatograph-mass spectrometry (GC-MS). Most of the volatile compounds were composed of pyrazine, alkane, ketone, esters and acids. This composition contributed to the flavor of Penaeus chinensis.The taste compounds of Penaeus chinensis waste were analyzed and the content of sugar, free amino acid compositions, ATP-related compounds, betaine and organic acid were investigated. It showed that the content of ATP-related compounds, suger, betaine was low. However, amino acid composition was rather abundant, in which the content of glutamic acid was the highest. The content of glycine alanine and arginine was also high. These amino acids could be used as resource for Maillard reaction.The operation conditions of the enzymatic catalysis using a combination of Alacase and Flavourenzyme were optimized by single factor experiment and response surface methodology(RSM). The operation conditions of enzyme combinations were:the first step, the substrate concentration10%, the dose of alcalase2%, pH6.5,65℃,3h; in the second step, the dose of flavourzyme2%, pH6.5,60℃,3h. Under the optimized conditions, the degree of hydrolysis was50.62%and the flavour of this product was strong.The Maillard reaction was investigated for improving the aromatic intensity and reflecting better shrimp flavor. The exogenous sugar and exogenous animo acids for the Maillard reaction were determined by single factor experiments. The exogenous sugars were xylose and glucos and animo acids were arginine and L-methionine. The effect of reaction temperature, reaction time, pH value, exogenous amino acids, and exogenous sugar were optimized by uniform designs. The optimum condition was as follows:the reaction temperature90℃, the reaction time40min, the pH6.5, the ratio of xylose and glucose was2:1, the ratio of arginine and L-methionine was1:3. The results of sensory evaluation were analysised by variance analysis to prove the difference between sensory evaluation was from the sample itself rather than the judge's ability. The maillard product was extracted by SPME and identified by GC-MS.47compounds were obtained. The compounds were composed of pyrazines, alkanes, acids, esters, aldehydes and ketones. The content of pyrazines and ketones were higher than other compounds. These compounds made this product reflect strong flavor. |
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