Effect Of Ultrasonic-glutamine Transaminase Modification On Enzymatic Hydrolysis Characteristics Of Wheat Gluten And Yeast

This article take wheat gluten protein-yeast hybrid system as the research object,disposed by ultrasound and turn glutaminase preprocessing of crosslinked enzyme(TG),using the alkaline protease Alcalase(2.4 L)and yeast extraction enzyme double enzyme hydrolysis prepared an outstanding freshness,coordinate the full flavor protease solution products.The changes on protein structure and the enzyme properties after physical modification and enzymatic cross-linking processing are systematicly studied,as well as the internal relations between hydrolysis parameters and the flavor material released from hydrolyzed wheat gluten-yeast hybrid system.The further analysis of wheat gluten protein-yeast hybrid system hydrolisate and separation of its umami components are also reserached.At last,This hydrolysis product with umami components is discussed and the inhibiting effect of different taste solution shows its application potential.By analyzing and comparing the structural characteristics and hydrolysis properties of wheat gluten protein-yeast protein effected by different pretreatment methods,It is found that compared with heating and homogeneous,ultrasonic pretreatment can increase protein molecular surface hydrophilic group content,promote the detachment of yeast dead cells which were mixed by protein-yeast protein.What's more,this treatment increases the the efficiency of proteolytic digestion by expanding contact area of YE-WG and enzyme.After ultrasonic-TG enzyme crosslinking treatment,the protein ?-turn is significantly reduced and ?-sheet increases greatly as well as the tasty score of the enzymatic hydrolysate.The optimal pretreatment conditions that can obtain ideal effect of enzymatic hydrolysis are followed: after 15 min 120 W ultrasonic processing in pH8.0,55 ? condition for enzymatic cross-linking of YE-WG hybrid system.The enzyme,the ratio of double enzyme,the total amount of enzymes and the time of enzymatic hydrolysis all have obvious effects on the release of proteolytic properties and flavor substances.In proportion to the protease Alcalase 2.4 L: yeast enzyme extraction enzyme = 1:3,the total enzyme amount added to 5 ‰(substrate)protein concentration under the condition of enzymatic hydrolysis of 20 h can obtain outstanding unami,bitter taste,the pleasant flavor protease solution.The protein recovery rate up to 70.21% and the degree of hydrolysis was 16.42%.Yeast extraction enzyme is effective to hydrolyse YE-WG,the existence of Alcalase 2.4 L stimulates enzyme hydrolyzing yeast protein extraction,probably because of yeast exonuclease can hydrolysis macromolecular protein into into macromolecular peptides,and Alcalase 2.4 L plays the role of further macromolecular peptides degradation,finally restriction enzymes in the yeast extraction enzyme turn the peptide into small molecular peptides which improved the efficiency of proteolytic digestion.To get highlight unami,lower bitterness,this paper,by using different concentration of ethanol solution to fractionation of YE-WG enzyme products and its potential applications as a condiment,found that 80% alcohol sink component obtained by ethanol fractionation has the most outstanding unami,which is 1.38 times that of the original enzymolysis liquid and yeast extract.It has obvious synergistic effect when it is mixed with MSG or I + G,which significantly improved the unami strength of two kinds,significantly enhance the awareness of salty.But there are different degrees of inhibition in sweet,sour and bitter taste.It has been applied to soy sauce and found that this component has a significant promoting effect in unami and salty of soy sauce.It is a qualified improvement agent of high quality potential soy sauce.