Study On Analysis Of Volatile Components Of Oyster Enzymatic Hydrolysate And Its Deodorization Process

Oyster,with its delicious taste and rich nutrition,plays an important role in aquaculture in China.Our country is always faced with the problem of low degree of oyster processing,backward deep processing technology,and the type and scale of oyster products to be broken through and improved.With the unremitting efforts of researchers,some progress has been made in the preparation of functional active peptides of oyster in recent years,but the fishy smell of oyster and its processing process limits the application of functional peptides of oyster and makes it difficult to realize high-value utilization.Therefore,it is an urgent technical problem to find a safe and effective way to remove fishy fish from oyster.In this paper,oyster antioxidant peptide was prepared by hydrolyzing with double enzyme.The changes of volatile flavor of oyster meat before and after enzymatic hydrolysis were compared with sensory evaluation and spme-gc-ms analysis to clarify the key flavor compounds of oyster meat and its enzymatic hydrolysis products.The effects of active yeast and chitosan treatment on the protein loss rate,amino acid nitrogen loss rate and fishy taste characteristics of oyster enzymatic solution were comprehensively studied and analyzed to optimize the defishy process of oyster enzymatic solution and provide theoretical and method guidance for the industrial preparation of high-quality oyster functional peptides.The effects of trypsin,complex protease,bromelain,flavor protease,papain and Alcalase2.4L on the enzymatic hydrolysis efficiency of oyster and the antioxidant activity of its enzymatic hydrolysates were studied using high protein and low fat oyster as raw materials.Through single factor and orthogonal experiment analysis,the optimum digestion parameters: the digestion system initial p H 8.0,the total amount of enzyme(pancreatic enzymes: flavor protease 3:1)as the oyster meat quality by 0.7%,enzymolysis temperature of55 ?,enzymolysis time 2 h,oyster liquid enzyme hydrolysis degree of 14.73%,DPPH ·clearance rate 89.51%,OH · clearance rate 15.65%,reducing power(A713nm absorbance value)is 0.822.Sensory evaluation and spme-gc-ms method were used to study the flavor changes of oyster meat before and after enzymatic hydrolysis,and the key flavor compounds of oyster meat and its enzymatic solution were determined by ROAV value method.The results showed that the oyster meat mainly presented grass and fruit flavor,accompanied by weak fishy taste and rancid taste,while the fishy and rancid taste of oyster enzymatic solution were prominent,and the grass and fruit flavor were weak,which was mainly related to the changes ofaldehydes and alcohols in oyster meat before and after enzymatic hydrolysis.Detect the 42 kinds of flavor compounds from oyster meat,oysters,enzymolysis liquid of the communist party of China to detect the 41 kinds of flavor compounds,including the key oyster meat flavor compounds(ROAV 1 or higher),there are four key flavor compounds and oyster enzymolysis liquid for seven kinds,oysters after enzymolysis rendering smell unpleasant smell flavor types and relative content increased,present a pleasant smell flavor types and relative content reduced.The result is that the flavor of oyster becomes worse after enzymatic hydrolysis.The effects of active yeast and chitosan on the flavor quality,amino acid content and DPPH· scavenging rate of the enzymatic hydrolysates of oyster meat were systematically studied,and the conditions for deacidification of yeast combined with chitosan were optimized to obtain the optimal deacidification process:Add oyster meat quality 0.6% of red wine yeast,trends under 40 ? for 30 min,then add the enzymolysis liquid quality concentration of 1% to 3% of the chitosan solution and let stand 20 min after 4500 r/min under centrifugal 5 min,the clear supernatant fluid,fruit fragrance,smell is weak,sensory score value of 7.5 points,flavor composition analysis found that the trends of oyster enzymolysis liquid of aldehydes,alcohols,furan,ketone matter content decreased,rendering pleasant odor compounds content increased;In addition,the combined deacidification treatment had little effect on the amino acids and antioxidant activities of the enzymatic solution of oyster meat,in which the loss rate of amino acid nitrogen was only 4.03%,and the loss rate of DPPH· clearance rate was 10.1%.The experiment shows that the yeast combined with chitosan defish-removing method is simple,fast and efficient,and has potential application value in the field of deep processing of aquatic products.