Study On The Process Of Controlled Enzymatic Hydrolysis Of Oyster Oligopeptides And Its Product Development

As the first batch of medicines and foods in China,oysters are delicious and nutritious.In 2018,the amount of oyster farming in China has reached 5.139 million tons.At present,the main utilization methods of domestic oysters are fresh-eating or condiments production,some oyster peptide products are also available,but the quality of the products is a motley crowd,which affects the development of the oyster market.Therefore,the deep processing of oysters and the development of new high-quality products are of great significance to the development of oyster industry.The oligopeptide is a peptide composed of 3 to 9 amino acids,and its relative molecular mass ranges from 180 to 1000.It has various advantages like good absorption,fast metabolism,high activity and so on.Oyster oligopeptides have many biological activities such as anti-oxidation,anti-tumor and blood pressure lowering.However,the traditional preparation process of oyster peptides in the current stage generally has low yield of oligopeptides,the ultrafiltration together with separation and purification processes after enzymatic hydrolysis are complicated,and the difficulties in enrichment,which have directly hindered the industrialization development.In this study,the oyster oligopeptides were enriched by controlled enzymatic hydrolysis technology,and the oyster-rich peptide beverage was developed by using modern blending technology,which opened up a new way for the high value utilization of oyster resources.The main research contents are as follows:(1)By investigating the effects of different proteases,physical pretreatment methods and enzymatic hydrolysis methods on enzymatic hydrolysis,it was determined that oyster homogenate was heat treated at 80 ? for 10 min and then animal protease was added as an efficient method for preparing oyster oligopeptides.On the basis of single factor experiment,the oyster enzymatic hydrolysis process was optimized by four-factor and three-level response surface analysis method,and the regression model was established.The optimum process conditions were determined as the ratio of material to liquid 1:3.9,and the enzymatic hydrolysis temperature was47 ?,the amount of enzyme added by animal protease was 3300 U/g,and the enzymatic hydrolysis time was 3 h at natural p H.Under this condition,the yield of oligopeptides was up to 58.53±1.20%.(2)The optimal concentration of oligopeptides,oligopeptides yield,and oligopeptides molecular weight of the oyster hydrolysate prepared by the new process increase to 46.13%,67.34%,57.78%,25.11%;and the color becomes lighter,clearer and translucent,the aroma is increased,and the astringency is reduced.It is judged by gas chromatography-mass spectrometry(SPME-GC-MS)technology that the relative content and ROAV value of the aldehyde compound with pleasant aroma in the new process increase,and two astringent alcohol compounds 1,5-octadien-3-ol,the relative content of 1-octene-3-ol and the decrease in ROAV value are important reasons for the weakening of astringency and the improvement of flavor.(3)Although the enzymatic hydrolysate prepared by co-enzymatic hydrolysis of ginger and oyster slightly reduces the yield of oligopeptides by 3%,it has a small astringency and a clear aroma of ginger,and the odor of the enzymatic hydrolysate is greatly improved.The single-factor orthogonal test was used to optimize the flavor formula and stability formula of oyster-rich peptide beverage,and the best formula was determined to be 5% composite sweetener,6% coconut powder,1.5%?-cyclodextrin and ethyl maltol 0.08%,xanthan gum 0.05%,pectin 0.05%,alginate propylene glycol 0.06%.The oyster-rich peptide beverage prepared under this condition has uniform texture,opalescent color,strong coconut flavor,moderate sweetness,delicate and non-sticky taste.The physical and chemical indicators and microbiological indicators of products are in line with national standards.In summary,this study uses controlled enzymatic hydrolysis technology to increase the proportion of oligopeptides in oyster enzymatic hydrolysate,and develops a oyster-rich peptide beverage with uniform texture,moderate sweetness and good quality by using modern deployment technology.