Study On The Technology And Mechanism About New Type Of Beef Paste Of Salty Flavor

China produces more than 12 million tons of bones each year,and bone protein extract is a common flavor ingredient.Enzymatic proteolysis technology provides a good technical choice for its development and deep processing.The use of enzymatic hydrolysis combined with thermal reaction technology to produce salty meat flavor is a relatively mature technology at present,but the meat flavor is not strong enough and realistic.In addition,high salt intake increases health risks,especially cardiovascular disease.Therefore,the development of a salty meat flavor with strong flavor and salt reducing function is of practical significance.This research is mainly divided into four parts.The first part is about the pretreatment of bovine bone proteolysis.In this study,beef bone was selected as raw material,and its basic nutritional components were analyzed.Before using flavor protease for enzymatic hydrolysis,the pre-enzymatic hydrolyzed samples were pretreated by ultrasonic,microwave combined with ultrasonic,and the effect of pretreatment on its taste,antioxidant activity,enzymatic hydrolysis efficiency and flavor substances was studied.The results show that both ultrasonic(US)and microwave combined with ultrasonic(MU)pretreatment can improve the degree of hydrolysis,but high-power ultrasonic(eg: 900 W,1200 W)combined with appropriate microwave treatment time(6 min)can improve the enzymatic hydrolysis efficiency more significantly(p < 0.05),the hydrolysates of MW6-US900 group and MW6-US1200 group had better taste and saltiness.MW6-US900 has the highest antioxidant activity and can significantly increase the ester content of the hydrolyzate.The second part is about the Maillard reaction model for the production of flavors under the control of lipid oxidation.Firstly,enzymatically hydrolyzed and mildly heat-treated beef tallow(EBF)was prepared by controlling fat oxidation,and then combined with EBF,phospholipid and microwave combined with ultrasonic pretreatment(MW6-US900),various Maillard reaction models were designed.The resulting Maillard reaction products(MRPs)were characterized.The results showed that the samples pretreated with MW6-US900 were more likely to participate in the Maillard reaction,and the brightness(L*)of MRP was relatively low.The MRPs(MRPs-A1,MRPs-B1,MRPs-C1)pretreated by enzymatic hydrolysis had higher saltiness and umami values.PLSR analysis showed that hexanal,nonanal,2-hexylfuran,2-hexylthiophene and 1-octanol were significantly positively correlated with the umami and saltiness of MRPs.EBF encapsulation treatment alone had little effect on the sensory properties of MRPs,while phospholipid treatment had a great effect on the composition of volatile compounds in the Maillard reaction system.The third part is a study on the efficacy of the MRPs-PHH,a low molecular weight peptide hydrolysate of pea protein,as a flavor regulator to reduce the salt content of meat flavor.The low molecular weight pea peptide hydrolyzate(PHH)was obtained by a two-step hydrolysis method,and then the Maillard product(MRPs-PHH)was prepared and formulated into the Maillard reaction system in which the meat flavor was determined in the previous stage.Finally,several beef flavors with different MRPs-PHH contents were prepared.The obtained essence products were compared with three similar products on the market,and their indexes such as antioxidant,color difference,texture,rheology and taste were measured and studied.The results showed that the flavor products containing MRPs-PHH had higher antioxidant activity,and the products with MRPs-PHH content of 10%(ME10)had the highest antioxidant activity.The hardness of ME5 and ME10 is lower than other products,and its chewiness is also higher than that of commercial flavors.The addition of MRPs-PPH can reduce the content of Na Cl in our prepared essence by 20%,and the salinity value has no significant difference(p ≥ 0.05).At the same time of the same salty taste,the Na content of ME5 and ME10 is more than 1/3 lower than the average Na content of the three commercially available beef flavors.The fourth part is about the optimization of Maillard reaction conditions in the preparation of beef flavor.Based on the research of the first three parts,single factor experiments were carried out on the addition amount,reaction temperature and reaction time of mild heat-treated tallow after enzymatic hydrolysis.Taking the maximum salty flavor and beef characteristic aroma value as the optimization objective,the optimal process conditions were obtained: the addition amount of mild heat-treated tallow after enzymatic hydrolysis was10.2%,the reaction temperature was 116.8℃,and the reaction time was 121.7 min.Under these conditions,the salty flavor and beef characteristic aroma value of the reaction product were the highest,6.39 and 6.48 respectively.