Stability Control Technology And Product Development Of Mytilus Edulis Enzymatic Hydrolysis System

Mytilus edulis is one of the most common economic shellfish in China.It is a marine shellfish with delicious meat,rich nutrition,high protein,low fat,various vitamins and mineral elements such as vitamins,calcium,phosphorus,zinc,and iron.The amino acid composition is perfect,of which the essential amino acid content is rich.The protein hydrolysates from Mytilus edulis(PHM),which has the physiological functions of enhancing immunity,anticoagulant,lowering blood pressure,and inhibiting bacteria.The Mytilus edulis protein oral liquid is a new type of functional active beverage developed through a series of processes such as seasoning and sterilization using PHM.In the study,it was found that the proteins in PHM produce stratification and precipitation during the zymohydrolysis,sterilization and storage,which not only affected the appearance of the product but also caused a decline in product quality.Therefore,controlling protein precipitation is one of the key technologies for the development of Mytilus edulis protein oral liquids.In this study,fresh Mytilus edulis were used as raw materials to select different proteases,control the concentration of protein in enzymatic solution,pH environment,and polysaccharide stabilizers such as xanthan gum were used to assist the treatment of high-pressure homogenization(HPH)to increase the storage stability of protease hydrolysate in Mytilus edulis.The stability of the PHM system was evaluated by detecting changes in the protein precipitation rate,turbidity retention rate,particle size,zeta potential,fluorescence intensity,and microstructure.At the same time,the color,flavor,taste and nutritive value of different PHM were evaluated,and a Mytilus edulis oral liquid product with excellent color,good taste and special seafood flavor was finally developed.Pepsin,neutral protease and trypsin were used to enzymatically hydrolyzed to fresh Mytilus edulis under the optimum conditions.The stability of the PHM was evaluated by the degree of hydrolysis,protein precipitation,molecular weight distribution and grain size.The PHM was then pH adjusted to 8.5 using a PB-10 pH meter with 0.5 M NaOH,and hydrolyzed by using trypsin(5000 U/g)at 45? for 2 h.The degree of trypsin hydrolysis was 13.2%,the protein extraction rate was 92.98%,and the precipitation rate was 9.52%.By examining the effect of different pH and protein concentration on the stability of the protein in the PHM.The lower the protein concentration,the greater the van der Waals attractive force and the electrostatic repulsive force between the protein ions in the system,and the stronger the alkaline environment of the system,the less likely the protein will aggregate and precipitate.The system was more stable at a protein concentration of 1 mg/mL and a pH of 8.0.CMC-Na,xanthan gum,?-cyclodextrin and Z-trim were added to PHM,and protein precipitation rate,particle size,Zeta potential,fluorescence intensity,and microstructure were used as indicators of the stability of the PHM system.The xanthan gum was found to have the best stability to the PHM system.Changes in the physical and structural properties of PHM caused by the adsorption of xanthan gum and homogenization could alter the tertiary structure of the protein.Moreover,the results showed that the addition of xanthan gum could enhance the storage stability of the protein.After HPH treatment,the complex showed a comparatively homogeneous network structure as determined by SEM analysis,and the system becomes more stable.Mytilus edulis is used as raw materials,high-pressure homogenized after adding a small number of auxiliary materials and stabilizers,and then autoclaved.The oral liquid prepared by the trypsin enzymatic hydrolysate has a unique seafood flavor and has a thick color,a high degree of clarity,a delicate taste,and a pleasant flavor.Rich protein content,low-fat content,total free amino acids up to 1263.5mg/Kg,the amino acid composition is perfect.The oral solution also contains a large number of mineral elements and trace elements such as potassium,calcium,zinc,and iron,and there are a large number of polypeptides that may have various biological activities.During the storage of Mytilus edulis protein oral liquid,the product's protein remained in a stable state without aggregation.The industrialization and Mytilus edulis processing use new ways to provide a certain scientific theoretical basis,promote the development of Mytilus edulis industry and provide utilization of Mytilus edulis.