提取牛背最长肌肌动球蛋白,用乙二胺四乙酸二钠(EDTA-Na2)完全抑制其三聚磷酸酶(TPPase)活性,与焦磷酸钠(TSPP)对比,研究三聚磷酸钠(STPP)水解对肌动球蛋白的解离、凝胶保水性(WHC)和凝胶强度的影响.结果表明:TSPP以及由STPP的酶解派生的TSPP均可以解离肌动球蛋白,并且提高蛋白的凝胶保水性和凝胶强度.而TPPase活性被完全抑制后,STPP不能解离肌动球蛋白,凝胶保水性和凝胶强度也没有得到提高.所以,STPP以三聚体形式存在时不具备解离肌动球蛋白的作用,只有被水解为TSPP才能解离肌动球蛋白.

【Objective】 The objective of this experiment is to study the pyridinoline cross-links of collagen and dissect its relevance to the shear force of beef.【Method】 Samples were divided into two groups.The first group consists of the same marbling with different ages.The second consists of the same age with different marblings.The shear force of beef,solubility and hydroxylysylpyridinium,lysylpyridinium of collagen were measured.【Result】According to the results of the first group,as bull aged,HP cross-links increased,LP cross-links increased firstly,and then decreased,which was followed by the decreasing of collagen solubility and the increasing of shear force.According to the results of the second group,as fattening,HP cross-links decreased,the solubility of collagen increased,and the shear force of beef decreased.【Conclusion】In the fattening,the synthesization of HP cross-link was restrained.There are shorts of mature cross-links in collagen,resulting in transition of gelatin more easily.So beef turns tenderer.

In this paper,the pH,protein solubility,dynamic viscoelasticity and gel properties(water-holding capacity(WHC),gel strength and gel elasticity) of fresh,chilled and frozen porcine longissimus muscle were conducted comparative comparison.The results showed that pH and protein solubility of fresh meat were the highest,and the gel properties and dynamic viscoelasticities were better.The pH and protein solubility of chilled meat were relatively low,and their gel properties and dynamic viscoelasticity were inferior to those of fresh meat.The pH,protein solubility,WHC and dynamic viscoelasticity of frozen meat were the lowest,however,the gel strength and gel elasticity of frozen meat were lower than those of fresh meat and higher than those of chilled meat.Therefore,refrigeration process can damage the functional properties of meat,and functional quality of fresh meat was the best.

This study was focused on a comparative evaluation of the sensory quality properties and processing characteristics of striploin and knuckle meats from Yanbian and Nanyang yellow cattles. Results showed that the a * value of Yanbian beef was significantly higher than that of Nanyang beef( P < 0.05), but the L * and b * values were significantly lower than those of Nanyang beef( P < 0.05). The juiciness of striploin from Yanbian cattle was better than that of Nanyang beef, while the juiciness of knuckle was worse than that of Nanyang beef. The cooking loss showed that Yanbian beef had a higher yield during processing than Nanyang beef. The striploin of Yanbian cattle had better tenderness with shear force of 3.19 kg/cm 2, which was suitable for frying and roasting. The gel p roperty of Yanbian beef was better than that of Nanyang beef, so Yanbian beef was suitable for preparing gel-type products. Nanyang beef had a better emulsifying property, and thuswas suitable for preparing emulsification-type products.

Totally,24 Simmental hybrid bulls at 18,36,54 and 72 months of age(6 for each age) were selected from the cattle farm of Anhui Da Ming company.The cattle were slaughtered and processed in a commercial plant.Fiber diameter,hydroxyproline content and shear force valueof the longissimus dorsi(LD) muscle were measured.The results showed that the shear force of LD muscle increased with the increase of fiber diameter and hydroxyproline content.The shear force was highly correlated with fiber diameter and hydroxyproline content,with r values of 0.833 and 0.835,respectively.The relationship between shear force and muscle fiber diameter could be described by the regression equation: y=1.162e0.034x(R2= 0.932).The regression equation of shear force versus hydroxyproline content was y = 1.793e27.430x(R2 =0.947).

[Objective] To understand and grasp the beef quality characterization of Xinan Cattle. [Method]6 bulls withl8 months Xianan bulls were selected from the cattle farm of XiaNan cattle technolo gy development company. The cattle were slaughtered and processed in TangHe slaughterhouse. Shear force values, fiber diameter,density of muscle fiber,color, juice of longissimus muscle and knuckle were measured. [Result]The results showed that muscle shear force values of longissimus was lower than knuckle. The L ＊ value of longissimus muscle and knuckle were not significantly different （ P 〉0.05）, while the difference of a ＊ and b ＊ value were significant （ P 〈0.05）. The juicy of longissimus muscle was better than knuckle. [Result]The commodity performance of Xianan cattle was significantly increased from the aspects of beef tenderness, color and juiciness,which would provide scientific proof for the further development of Xianan cattle.

A method for determining the emulsifying capacity of porcine muscle protein was developed by determining optimal experimental conditions for the emulsification of soybean oil by means of one-factor-at-a-time experiments and validation experiments.The results showed that when its homogenate at pH 6.25 was sheared at 8000 r/min and ambient temperature for 10 s and then left to stand for 10 min,the emulsifying capacity of porcine muscle protein was 55 mL of soybean oil per gram of sample,which was in basic agreement with 53 mL of soybean oil per gram of sample obtained by shearing at 8000 r/min for 10 s and then standing for 30 min.In conclusion,reliable and applicable experimental conditions for determining the emulsifying capacity of porcine muscle protein have been established.

Smoked meat products are very popular worldwide.The traditional smoking technology has defects,easily leading to the pollution of polycyclic aromatic hydrocarbons(PAHs) and formaldehyde.This paper outlines some defects of the traditional smoking technology and put forward the solutions: inhibiting the formation of PAHs and using liquid smoking.The first solution has limitation and can not solve the problem of formaldehyde pollution.However,the second not only retains the flavor of traditional smoked meat products,but also yields safe and healthy products,thus being worth advocating and popularizing.