| Beef tenderness is one of the most important factors affecting taste.Yak beef tastes old and hard,mainly due to its longer growth cycle.Therefore,improving its tenderness is a top priority.The factors that determine tenderness can be divided into muscle fibers and connective tissues in terms of structure.At present,the study of the role of muscle fibers is more thorough,and the role of intramuscular connective tissue is not very thorough.This article uses sour tangerine juice combined with vibration to process yak beef,to study the processing conditions of sour tangerine juice on yak beef,the parameters of vibration and tenderization of yak meat,and to use scanning electron microscope and transmission electron microscope to observe the microscopic under vibration Structural changes to explore the potential value of sour tangerine juice and vibration treatment for tenderizing yak beef,and provide new technology for tenderizing yak beef The research results are summarized as follows.1.The effect of sour tangerine juice on the shear force value and intramuscular connective tissue of yak meatThe supraspinatus and quadriceps muscles were compared.After standing for a certain period of time in different concentrations and feed-liquid ratios of sour tangerine juice,the changes in yak shear force value and intramuscular connective tissue.In different concentrations of sour tangerine juice solution,supraspinatus esculentus’ cooking loss increases with the increase of concentration;the shear force value decreases with the increase of concentration and then increases.In different material-liquid ratios,the cooking loss increases with the increase of the material-liquid ratio;the shear force value gradually decreases with the increase of the material-liquid ratio;the pH value is negatively correlated with the material-liquid ratio,and the material-liquid ratio increases,The pH value gradually decreases.The quadriceps in different concentrations of sour tangerine juice solution,as the concentration increases,the cooking loss increases,and the shear force value and pH value gradually become smaller.In the tangerine quadriceps in sour tangerine juice solutions with different feed-liquid ratios,the cooking loss increases as the feed-liquid ratio increases;the shear force value becomes smaller and the pH value gradually becomes smaller.Appropriate tenderization conditions for sour tangerine juice obtained after a single factor test:a solution with a concentration of 1%and a material-liquid ratio of 1:2.Under the optimal treatment conditions,the total collagen content of supraspinatus and quadriceps muscles decreased and the thermal solubility increased.Under the optimal treatment conditions,the muscle tissue is separated,ruptured,and dissolved;the intramuscular connective tissue is also separated and the outer wall is ruptured.2.The effect of vibration on the shear force value and color difference value of yak maetPlace the dorsal longest muscle in a solution with a concentration of 1%and a material-to-liquid ratio of 1:2,and seal.Placed in the vibration tenderization equipment,under the condition of a certain frequency,by changing the amplitude and time,to determine the appropriate tenderization parameters.Then,under this condition,the changes of tenderness and structure of yak meat of different ages were compared.When the amplitude is 2 mm,the shear force value is the lowest.The L*value,a*value,and b*value all decrease first as the eccentric angle increases,and then become larger.As the eccentric angle increases,the weight gain rate increases first and then decreases.The amplitude has no significant effect on pH.The range of weight gain rate is between 2%and 6%.The vibration time is 1 h,the shear value is the lowest,and the weight gain rate is the lowest.The vibration time has no significant effect on the shear force value and pH value.The effect of vibration time on the L*value,a*value,and b*value is not significant.The 3-year-old yak meat had the lowest shear force value.As the age increased,the shear force value became larger,the pH value became larger,the weight gain rate became smaller,and the L*value and b*value became smaller.Observed through a stereo microscope,vibration has a greater effect on the structure of 9-year-old yak meat.After vibration,the structure becomes loose,pleats appear,and the degree of damage is weak.Through the single factor experiment,the tenderization condition of the equipment was obtained:at a frequency of 40 Hz,the amplitude was 2 mm,and the time was 1 h.Under this condition,the yak beef shear value is the lowest.3.The effect of vibration and sour tangerine juice on the covalent cross-linking and ultrastructure of the dorsal longest muscleAccording to the treatment conditions,it is divided into three groups:control group,static group and vibration group.Yak beef MFI value increased from 33 to 35,no significant changes were found.The HP content increased from 59 to 67(p>0.05);the LP content changed from 30 to 41(p<0.05).After vibration,it can be seen by transmission microscope that the overall structure remains intact,the Z line is intact,and the length of the sarcomere is not significantly changed.Most of the M line is still visible,and the proteins near the M line disappear.The scanning microscope found that after treatment,the collagen honeycomb structure became loose,and the muscle fiber structure remained basically intact,but the gap between each other became larger.In summary,the main object of the sour tangerine juice solution under the vibration condition is collagen. |
