肉品品质的无损检测方法

目前,国外肉品生产发达国家正在研究与应用无损检测手段进行肉品的品质评定。本文介绍了肉品品质的各种无损检测方法的基本原理、作用及其优缺点,包括超声波检测技术、利用电磁学方法检测(主动特性法和核磁共振波谱分析技术)、电子气味检测法(电子鼻)、光学方法(近红外光谱分析技术和激光喇曼光谱技术)和计算机视觉检测技术。     

The Relation of Force to Sample Dimensions in Objective Measurement of Tenderness of Poultry Meat

SUMMARY: Relations between maximum shear resistance and cross-sectional dimensions were established for cooked turkey meat samples of various shapes and sizes with a Warner-Bratzler type shearing device mounted in an lnstron tensile tester. The resistance to shear was proportional to the equivalent diameter raised to a power of about 1.2, over a wide range of sizes, shapes and intrinsic toughness. Degree of compaction before shearing was significantly correlated ( r = 0.65, significant at 0.1% level) with the force at first failure per unit of equivalent diameter, and the compaction naturally increased with increasing intrinsic toughness. These data will permit comparison of shear force measurements from meat samples of different sizes and shapes.     

Water Binding Measurement of Meat

A quick technique for measuring cooking yield based on microwave heating was compared with a modified cooked-centrifuge technique for determining water holding capacity and both were compared with the standard raw-press technique for determining water holding capacity. In general the results of the three methods were highly correlated; however, limitations of each method were noted. The effects of additives such as salt, phosphate and binders were evaluated along with the effects of time postmortem and freezing-thawing. The influence of fat was also evaluated and a variety of sausage raw materials were analyzed by the three techniques.     

A Comparison Between Two Different Shear Systems Used for Measuring Meat Tenderness

A comparison has been made between two Warner-Bratzler (WB) shear devices, differing in their method of operation, used in measuring tenderness of meat samples treated to produce a wide range, in both myofibrillar and connective tissue structural strength. Estimates of parameters measured from the shear deformation curves obtained from the two systems were highly correlated and both systems showed similar and significant responses to the treatments used to modify the structural components of meat.     

剪切力对必特螺旋霉素发酵的影响

目的 考察剪切力对必特螺旋霉素发酵的影响.方法 考察摇瓶发酵过程中玻璃珠数量、添加玻璃珠时间及不同发酵阶段添加玻璃珠对发酵的影响.50 L发酵罐上,通过改变搅拌速度调整对菌体的剪切力,并考查不同发酵阶段剪切力对发酵的影响.结果 随着玻璃珠数的增加,菌体浓度和必特螺旋霉素产量下降明显;48 h时添加玻璃珠对必特螺旋霉素合成有促进效果,效价提高8%,且菌体浓度变化不大.发酵前期(0～48 h)和发酵后期(72～96 h),过强的剪切力会对发酵产生不利的影响.在50 L发酵罐上,不同发酵阶段调整剪切力,使发酵产物单位数比对照提高1 6.7%.结论 剪切力对必特螺旋霉素发酵有显著影响.     

2005年中国国际肉类工业大会国际肉类企业盛大会师

<正>今年7月20-23日,2005塞飞亚中国国际肉类大会暨中国肉类协会会员大会及中国国际肉类工业展览会在北京世纪金源大酒店、北京展览馆相继召开。本次大会和展会由世界肉类组织、中国肉类协会联合主办,美国肉类出口协会、澳洲肉类及畜牧业协会、爱尔兰食品局协办。举办本次大会的主要目的是向全行业及相关企业发布中国肉类工业发展动态信息;为全行业及相关企业提供互     

基于物理机械力的苎麻脱胶新技术

介绍了一种基于物理机械力的苎麻脱胶新工艺及试验设备,详述了工艺流程和步骤,专用设备的功能作用,以及苎麻脱胶制纤的实际效果。     

A Modified Sample Preparation Method for Measuring Meat Tenderness by the Kramer Shear Press

Tenderness of steaks and diced meat was evaluated by sensory panel, Wainer-Bratzler shear press and modified Kramer shear press which employed coarse grinding of meat through a food chopper and shearing duplicate 20g samples of ground meat by the Kramer shear device. Highly significant (P < 0.01) correlation coefficients of -0.88 and -0.80 were obtained for the steaks and diced meat, respectively, between sensory score and modified Kramer shear value. A correlation value of 0.90 between W-B shear values and modified Kramer shear values was also highly significant. The results strongly indicate that the modified sample preparation method is a simple, reliable and versatile method which is less influenced by experimental variables and is applicable to almost any kind of meat products.     

肉糜制品质地的测定

肉糜制品的质地测定有多种方法,如W-B剪切、穿刺和压缩试验等.通过结果比较,发现3种方法测得的硬度值呈线性相关,而且每种试验硬度值和功也都线性相关.对于因样品脂肪含量不同所导致的硬度变化,压缩试验最为敏感.     

剪切力对造纸湿部絮凝作用的影响

本文综述了剪切力对造纸湿部絮凝作用的影响,内容包括造纸过程主要单元操作中的剪切力水平及其对絮凝的影响、剪切力大小的评价、选择性解聚的现象、不同助留体系形成絮体的抗剪切性和可逆转性以及絮凝过程控制.     

制服面料的力学性能对服装成衣加工性的影响

文章采用KES系统对16种制服面料在低负荷下的拉伸性能、剪切性能、弯曲性能、压缩性能、表面性能等进行测试,通过绘制缝制加工控制图分析制服面料的力学性能与成衣加工性能的关系,为制服面料成衣加工提供理论依据。     

Effect of Cooking Temperature and Time on the Shear Properties of Meat

The effect of cooking temperature in the range 40–95°C on Warner-Bratzler shear force-deformation curves, obtained for stretched and cold-shortened meat samples from young and old bovine animals, has been investigated. The results were interpreted as indicating that the relative contributions of the connective tissue and myofibrillar structures to the peak shear force values were markedly altered as cooking temperature was increased. The changes of the myofibrillar structure were reflected by the changes in initial yield force values. In general, the initial yield force increased about three- to fourfold between 40°C and 60°C for both stretched and cold-shortened meat but between 60°C and 80°C the increase was about twice for the former and about fivefold for the latter. The connective tissue contribution decreased as cooking temperature was raised above 50°C for meat for young animals and above 60°C for very old animals–the contribution at temperatures above 70°C being very small for the former but still relatively large for the latter.     

Objective Measurement of Connective Tissue Tenacity of Poultry Meat

SUMMARY— A direct, objective method was developed for measuring the cohesive force holding the fibers and fiber bundles of poultry meat together, i.e., the connective tissue tenacity. The method consists of cutting out uniform cylinders of cooked muscle with the fibers parallel to the plane ends of the cylinder, attaching metal plates to the cylinder ends by a special adhesive that forms strong bonds with moist tissue, and measuring the force and work required to tear the meat sample apart in a recording tensile tester. Ability of the method to measure the cohesiveness between fibers, independent of the force required to shear across the fibers, was evaluated by determining connective tissue tenacity, shear force, alkali insoluble hydroxyproline (index of collagen), and taste panel reactions on cooked muscle samples varying with respect to age of bird, post-mortem aging condition, freeze-drying, and cooking time. Connective tissue tenacity was directly correlated with alkali insoluble hydroxyproline (r = 0.91, P < 0.001), inversely related to cooking time, and in general appeared to be a good measure of the connective tissue component of toughness as differentiated from the component related to force required to shear across the fibers. The method will be useful in objectively measuring the quality defect of lack of cohesiveness in canned, freeze-dried, and irradiated poultry meat, and should be of general value in all research on meat quality.     

Shear Force Values for Steaks from the Semitendinosus Muscle of Pre-Rigor Leg-Twisted Beef Carcasses

The imposition of leg-twist treatment to intact beef carcass sides increased the mean, mode and median of the shear values of cooked semitendinosus muscle. Steaks from treated sides were uniformly tougher than steaks from nontreated sides. In both treated and nontreated sides, the anterior end of the muscle was tougher than the posterior end.     

均匀设计和回归分析在肉香味物质制备中的应用

利用均匀设计法在有丝氨酸参与的美拉德反应条件下,对样品用5个细化的指标评分,通过多项式回归拟合该反应的回归方程,分析各因素及交互作用对反应的影响,结合回归方程和实际情况找到了最佳的反应条件为:丝氨酸2.000g,丙氨酸1.640g,半胱氨酸2.400g,木糖5.646g,水27.267g,系统pH值8.2,在120℃下反应53min。     

机械式壳肉分离加工河蟹的研究

将河蟹蟹身、蟹脚、蟹钳进行分类,分别采用皮带挤压、滚轴挤压、真空吸滤的方法进行壳肉分离,以蟹肉得率、分离效率、蟹肉品质作为评价指标,对比壳肉分离效果,结果表明:皮带挤压最适合蟹身壳肉分离,蟹肉得率可达68.2%,分离效率可达50 kg/h,蟹肉品质最好;滚轴挤压最适合蟹脚壳肉分离,蟹肉得率为35.8%,分离效率为6.8 kg/h,蟹肉品质最好,真空吸滤最适合蟹钳壳肉分离,蟹肉得率为44.1%,分离效率为5.1 kg/h,蟹肉品质最好。     

不同肌纤维走向下牛肉剪切力的差异

肌纤维走向(平行或垂直于肌纤维)影响牛肉的各项嫩度指标,该研究从肌纤维和结缔组织两方面出发探究肌纤维走向引起嫩度差异的原因。以牛半腱肌为原料肉,分别在60、70、80、90、100 ℃的水浴温度下加热30、60、90、120、150 min,测定不同肌纤维走向下的剪切力、结缔组织机械强度、质构特性、胶原蛋白共价交联的变化以及扫描电镜观察,最后通过相关性分析得出肌纤维走向影响嫩度的关键因素。结果显示,相同温度和加热时间下,垂直于肌纤维方向的剪切力、硬度、凝聚性显著高于平行方向(p<0.05)。垂直肌纤维方向的剪切力与结缔组织机械强度和咀嚼性呈极显著正相关(p<0.01),与硬度、胶黏性、羟赖氨酸吡啶含量呈显著正相关(p<0.05);平行于肌纤维方向的剪切力与硬度、凝聚性、胶黏性、咀嚼性、回弹性呈极显著正相关(p<0.01),与结缔组织机械强度呈显著负相关(p<0.05)。由此得出垂直方向的嫩度特性由肌纤维和结缔组织共同决定,平行方向的嫩度特性由少数结缔组织和肌纤维变形挤压力决定。     

猪肉剪切力的测定方法

为建立可靠、规范的猪肉剪切力测定方法,研究不同加热中心温度(65～80℃)、水浴温度(70～80℃)、保温时间(0～20min)及冷却温度(0～25℃)对猪背最长肌剪切力值和蒸煮损失的影响。结果表明：猪肉的剪切力和蒸煮损失随着中心温度和水浴温度的升高、保温时间的延长而增加,冷却至0～4℃的肉样其剪切力值的变异系数最小,不同的预处理方法对猪肉剪切力的影响差异显著。综合而言,猪肉剪切力测定的预处理条件应为：水浴温度72℃,加热至中心温度70℃,不保温,煮后肉样放至0～4℃冷库中过夜。     

Sensory Scores and Shear Force Values for Beef Roasts Cooked Either Before or After Chilling

Sensory and physical characteristics were determined on beef semimembranosus and semitendinosus muscles removed and cooked either 1.5 hr post-exsanguination or after 7 days of chilling by either steam, hot water vat or convectional electric cookery. The effects of cookery method on sensory and physical characteristics were not statistically significant (P > 0.01). Hot-boned roasts from both muscles served as cubes had higher shear force values, higher amounts of connective tissue (sensory panel), and lower tenderness and higher juiciness scores than cold-boned cooked roasts. However, no differences in sensory characteristics were found between hot-and cold-boned cooked semitendinosus roats evaluated in a thinly sliced form. These results suggest that acceptable tenderness in beef roasts cooked hot-boned may be achieved when the product is used in a thinly-sliced or similar form.