Preparation Of Hydrolysate From Preserved Egg White And Its Anti-inflammatory Activity And Application

Peptides with its small molecular weight,easy absorption,thermal stability,security and other natural features,have become one of the hot areas of modern food science and biotechnology.Preserved egg is a traditional flavor of food from eggs with an alkali effect.A variety of proteins from eggs provide a rich foundation structure for the preparation of polypeptides which is from eggs with an alkali effect.In this paper,preserved egg was selected as the researching objective,proteolysis process and polypeptide beverage recipe optimization were studied with response surface methodology,anti-inflammatory activity of water extract of preserved egg and peptides also were studied.Main research contents and results are as follows:(1)In this study,neutral protease,papain,alkaline protease were selected to enzyme egg protein.According to the peptide content of single enzyme and complex enzyme combination,complex enzyme combination(Alkaline protease: neutral protease=1:1)was chosen as the optimum enzyme to hydrolyze egg protein.Response surface methodology was used to model and optimize responses(Peptide content)based on the single factor experiment.Hydrolysis conditions,such as hydrolysis temperature,hydrolysis time,enzyme concentration and hydrolysis pH,were selected as the main processing conditions in the hydrolysis of preserved egg.The optimal conditions for hydrolysis were: a hydrolysis temperature of 57.64°C,a hydrolysis time of 91.85 min,a pH value of 10.39,an enzyme concentration of 56200 U.Under these conditions,the model predicted a peptide content of 54.989 mg/g,actual conditions of the final enzyme solution were: a hydrolysis temperature of 57.6°C,a hydrolysis time of 91.9min,a pH value of 10.4,an enzyme concentration of 56200 U.Actual content of polypeptide was 53.011 mg/g,the relative error is 3.6%.(2)TNF-?-induced Caco-2 cells were chosen as inflammatory model for research of water extract and peptides of preserved egg in this paper.IL-8 was measured by ELISA.Results show that middle and high dose groups(2.5-10 mg/mL)of water extract of preserved egg could significantly reduce the secretion of IL-8.Dose-dependent manner showed overall and better anti-inflammatory effect showed with higher sample concentration.low,middle and high dose groups(0.5-10 mg/mL)of water extract of preserved egg(?5kD)could significantly reduce the secretion of IL-8.Best anti-inflammatory effect showed when sample concentration was 10 mg/mL;high dose groups(5-10 mg/mL)of peptides from preserved egg could significantly reduce the secretion of IL-8,but there was no significant difference between the dose groups,middle and high dose groups(2.5-10 mg/mL)of peptides from preserved egg(?5kD)could significantly reduce the secretion of IL-8 and there was significant difference between the dose groups.Best anti-inflammatory effect showed when sample concentration was 10 mg/mL.(3)Response surface methodology was used to model and optimize responses(beverage sensory score)based on the single factor experiment.A polypeptide content,a malic acid content,a white sugar content,an orange juice content were selected as the main processing conditions in this study.The formula was determined at last: a polypeptide content of 2.7%,a malic acid content of 0.19%,a white sugar content of 8.59%,an orange juice content of 0.5%.Under the optimal conditions,the beverage sensory score results to 87 points.Actual conditions of the final formula solution were: a polypeptide content of 2.7%,a malic acid content of 0.2%,a white sugar content of 8.6%,an orange juice content of 0.5%.Actual beverage sensory score results to 85 points.The relative error is 2.3%.