Effect Of Ultrasonic-Assisted Complex Enzyme Treatment On The Oualitv Of Frozen Horse Meat Patties

Using horse hind leg meat as raw material,the quality changes of horse meat patties during freezing storage were first observed.Secondly,by adding papain,actinidin,a complex enzyme of these two enzymes,and ultrasonic-assisted complex enzyme before freezing,the edible quality changes of horse patties after thawing were studied.The optimal conditions for papain,actinidin,and the combination of these two enzymes to tenderize horse meat patties and the best conditions for ultrasonic assistance were optimized.Finally,the effects of horse meat patties treated with complex enzyme and ultrasonic assisted complex enzyme on the water-soluble total nitrogen content,myofibrillar fragmentation index,soluble protein content,collagen solubility,myofibrillar protein content,volatile flavor substances and ultrastructure were studied.The experimental results are as follows:(1)With the extension of frozen storage time(0-9 months),the thawing loss of horse meat patties gradually increased;The hardness index increased first and then decreased;There was no significant difference in the pH value of horse meat patties(P>0.05);the L*value and a*value gradually decreased,and the b*value gradually rising;Sensory evaluation scores were gradually decreasing.(2)Six proteases were selected under the optimal enzymolysis conditions,with thawing loss,hardness,and sensory evaluation as the indicators.Finally,papain was selected as the optimal enzyme and actinidin was selected as the suboptimal enzyme.The single factor and response surface experiments were used to determine the optimal process parameters of papain:42 U/g papain,pH 7.0 and 26.5 h,and the hardness of horse meat patties after papain treatment was 2.68 N.The optimal process parameters of actinidin:25 U/g actinidin,pH 6.0 and the hydrolysis time is 12 h.Under these conditions,the hardness of horse meat patties hardness was 3.31 N.(3)The complex enzyme method was used to improve the horse meat patties process optimization.The single factor and response surface experiments were used to determine the best process parameters:the ratio of papain to actinidin complex enzyme was 1:2,pH 6.3 and enzymatic hydrolysis 8 h.At this time,the enzymolysis conditions were optimal,and the hardness of the horse meat patties was 2.29 N.(4)To study the effect of ultrasonic-assisted complex enzymes on the quality of horse meat p atties.Compared to the control group,the thawing loss of horse meat patties treated with ultrasoni c-assisted complex enzymes decreased significantly(P<0.05);The hardness index was significantly r educed(P<0.05);The effect of pH is not significant(P>0.05);The L*value of horse meat patties i mproved(P<0.05);The b*value of horse meat patties had no significant effect(P>0.05);The a*va lue of horse meat patties was increased within 30 minutes of ultrasonic treatment,but the a*valu e of horse meat patties was decreased after 30?50 minutes of ultrasonic treatment;Under the same ultrasonic treatment time and different ultrasonic power,the a*value of horse meat patties did n ot change significantly(P>0.05).When the ultrasonic treatment conditions were 150 W and 20 min,the quality of horse meat patties was the best.(5)Compared with horse meat patties treated with complex enzyme,the water-soluble total nitrogen content,MFI,CSP,collagen solubility of horse meat patties treated with ultrasound-assisted complex enzyme increased significantly(P<0.05),but myofibrillar protein content decreased significantly(P<0.05).The SDS-PAGE atlas showed that the macromolecular protein in the horse meat patties treated by the ultrasonic-assisted complex enzyme treatment was hydrolyzed into small molecules.Ultrasonic-assisted complex enzyme treated horse meat patties microstructure shows a uniform and delicate three-dimensional network structure with fewer holes.A total of 33 volatile flavor substances were detected in the horse meat patties in the complex enzyme treatment group,and a total of 49 volatile flavor substances were detected in the horse meat patties after ultrasonic-assisted complex enzyme treatment.