胶原蛋白与肉品品质

简要介绍了胶原蛋白在肌肉中的分布,交联结构的形成及其稳定性,并阐述了胶原蛋白随动物年龄变化的规律及其与肌肉嫩度之间的关系。     

探讨影响肉质嫩度的因素和嫩化方法

<正> 肉的食用感官指标主要包括滋味、质地、多汁性、外观色泽和气味等,其中以代表质地品质的嫩度最为重要,它决定着肉的烹调和加工产品的最终感官质量,是消费者选择肉和肉制品的首要衡量指标。 影响肉质嫩度的因素 在评定肉的嫩度时,除了品尝试验外,目前最常用的方法是测量剪断单位体积肉品所需的机械力。事实上,肉的嫩度取决于肌肉中肌原纤维蛋白的状态(即肌球蛋白与肌动蛋白结合的紧密程度)、结缔组织的组成和含量、肌间脂肪的分布和含量,以及肌肉持水性的大小。一般来说,在结缔组织含量低,尤其是弹性蛋白含量低的情况下,肌肉便处于解     

宰后肉品pH值与嫩度

详细论述了宰后肌肉僵直收缩的pHu、pH-温度的下降速率对肉品最终嫩度的影响,并介绍了肌肉的僵直收缩基本原理,收缩过程中线粒体肌浆网功能的变化引起肌细胞质中Ca2 浓度变化,ATP含量降低,pH值下降,形成肌动蛋白与肌球蛋白间的僵直联结。     

原料肉嫩度影响因素

在肉的加工过程中,嫩度非常重要,是评价肉及肉食品综合品质的一项重要指标,直接影响着肉的食用价值和商品价值,反映着肉中各种蛋白质的结构状态与特性。在市场竞争日益激烈的今天,如何生产出嫩度高,口感好的肉及肉食品,已经成为食品行业一项非常重要而又实际的研究内容。本文主要从宰前因素和宰后因素对原料肉嫩度的影响加以阐述。1宰前因素对原料肉嫩度的影响1·1年龄幼龄家畜的肉一般比老龄家畜的肉嫩。原因是老龄家畜因胶原蛋白共价交联键较多,有较高的热稳定性,对酸碱等的敏感性也相对较差,而幼龄家畜肌肉中胶原蛋白的交联程度低,热稳定…     

钙蛋白酶系统对肉的嫩化作用研究进展

肉的嫩度是肉品质的一个重要指标,严重影响肉的食用价值和经济价值.钙蛋白酶系统通过水解肌原纤维蛋白,在宰后肌肉嫩化中起着决定性的作用.综述钙蛋白酶系统(包含钙蛋白酶、钙蛋白酶抑制蛋白和钙蛋白酶激活蛋白3部分)对肉嫩化的作用机制和研究现状,并探讨研究前景.     

Psychophysical investigations into the tenderness of meat

Tenderness of five veal meat cuts was determined by two groups of subjects: a panel of skilled butchers and a consumers' panel. The butchers estimated tenderness with and without assistance of visual information. For the consumers a procedure to measure the oral sensation by a forced choice method of successive comparison was developed. It was shown that: imprecision of the opinions of the consumers was greater than that of the butchers; use of additional visual information did not affect the butchers' precision; and the butchers' views of tenderness had a poor relationship to the consumers' oral perception of this quality.     

细胞凋亡酶在肉品成熟过程中对其嫩度影响的研究进展

综述了近年来有关细胞凋亡酶在肉成熟过程中的研究新进展,包括:细胞凋亡酶的种类、激活途径,对蛋白水解作用的调控机制,细胞凋亡酶参与蛋白水解的不同途径,细胞凋亡酶与钙蛋白酶之间的相互作用。从多方面论证肉品成熟过程中细胞死亡的主要方式为细胞凋亡;同时,就细胞凋亡酶在肉品成熟中的作用机制提出一些新思路。     

肌纤维类型与肉嫩度的关系

阐述了肉的肌纤维与宰后嫩度形成之间的联系,发现由于肌肉宰后消耗能量、产生代谢产物与活体具有不一样的方式,而这个方式因肌纤维差异而存在不同之处,这就会影响到肌肉宰后能量与代谢水平的平衡,进而对肌肉宰后成熟产生调控作用,最终极有可能影响其嫩度的形成。      

Influence of ultimate pH on bovine meat tenderness during ageing

The aim of this work was to evaluate the influence of ultimate pH and ageing at 2±2°C on the tenderness of beef. The m.longissimus thoracis et lumborum from 23 young bulls excised at 28 h post mortem were grouped into: Normal (pH 5.5 to 5.8) moderate DFD (mod DFD) (5.8p<0.05) lower in the DFD group than in the Normal one and a significant (p<0.001) linear relationship was found between ultimate pH and tenderness as evaluated by both methods. The myofibrillar protein solubility (MPS) at pH 7.0 was significantly higher in the DFD group at all post mortem times whereas for myofibrillar fragmentation index (MFI) higher values (p<0.05) were only found in the DFD group at day 1. In all three groups toughness decreased (p<0.05) from 1 to 6 days, with no further decrease to 13 days. This decrease in toughness was associated with an increase of MFI in all pH groups. Collagen solubility in all three groups was not affected by ageing. No significant (p>0.05) differences in soluble collagen and myofibrillar protein solubility (MPS) at pH 5.5 were found between the pH groups at any time. The tenderness evaluated by both methods was significantly (p<0.05) related to MFI, MPS at pH 7.0, cooking loss and juiciness. Total and soluble collagen, sarcomere length, intramuscular fat and MPS at pH 5.5 were not significantly (p>0.05) related with tenderness.     

肉类嫩化技术的研究进展与思考

肉的嫩度是肉品品质的重要指标,肉嫩度的改善一直是国内外肉品科学研究的热点之一。本文阐述了肉品嫩化的电刺激技术、嫩化吊挂技术、成熟技术、钙离子注射法、机械法、盐和有机酸嫩化法以及酶法嫩化等,并对这些技术进行了探讨,提出了看法和建议。      

动物宰后肌内胶原蛋白变化与肉嫩度关系分析

动物肌内结缔组织对肉的嫩度起到重要的影响作用,这些影响主要是通过肌内膜和肌束膜内胶原蛋白的变化而影响肉的嫩度,表现为胶原蛋白的含量、热溶解性、交联程度以及热变性程度等.而胶原蛋白的这些特性还受到动物宰前和宰后诸多不同因素的影响,进而影响到肉的嫩度,本文综述了胶原蛋白在宰后成熟、加热烹调、超声波和高压嫩化处理以及弱有机酸结合NaCl腌制中的变化,分析和阐述了胶原蛋白的变化对肉嫩度的影响.     

Time-intensity as a tool for the measurement of meat tenderness

In the texture analysis of meat, tenderness is an attribute that changes over time from the initial bite to the residual phase before swallowing. In this study, continuous time-intensity measurements were recorded on a line scale and compared to a single time-averaged measurement. Thirty gluteobiceps gilt roasts representing two breeds and cooked at three oven temperatures were evaluated by eight trained assessors. Cores, taken both perpendicular and parallel to the muscle fibre, and slices were sampled from each roast. Assessors recorded their perception of tenderness continuously from initial bite to swallowing by moving a cursor on a computer screen (time-intensity) and over a chew count of eight (time-averaged). Results based on parameters summarizing the time-intensity curves were comparable to those of the time-averaged data. The time-intensity curves clearly illustrated the temporal features of the perception of tenderness.     

复合磷酸盐对鸭肉饼嫩度的影响

研究焦磷酸盐与三聚磷酸盐的复合磷酸盐添加量和冰水添加量对鸭肉饼嫩度的影响.结果表明鸭肉饼较好嫩化的条件为:焦磷酸盐:三聚磷酸盐为1∶2,复合磷酸盐添加量为0.4％,冰水添加量为25％.其中,在3个因素中复合磷酸盐添加量对鸭肉饼嫩度的影响最大,其次为焦磷酸盐:三聚磷酸盐,水分影响最小.     

Impact of introducing specifications on the tenderness of retail meat

Over a 3-year period (1997-1999), the shear force of 4371 retail beef, lamb and pork midloin samples collected from 363 retail outlets were tested using a MIRINZ tenderometer. Information about aging time, processor and retail chain was recorded. Consumers (n=2313) were also surveyed on their perception of the tenderness of beef and lamb midloin samples with known shear force. The results validated that shear force, as measured by the MIRINZ tenderometer, could be used to create instrumental tenderness categories which reflected consumer perceptions of tenderness. Over the 3-year sampling period, the shear force of beef and lamb decreased by 21.9 and 17.2%, respectively, and there was a consistent decrease in the number of 'tough' samples. The improvement in tenderness coincided with the introduction of a Quality Mark program in 1997 for beef and lamb and 3 years of implementation by auditing. The Quality Mark program sets specifications for the quality of retail meat in New Zealand and guidelines to achieve these specifications. In comparison to retail beef and lamb, the shear force of retail pork decreased marginally by 7.9%. Furthermore, the decrease in the number of 'tough' pork samples was not consistent over the testing period. Analysis of these data showed that for all three meats a considerable improvement in tenderness can be achieved by adopting a minimum post-slaughter aging time and optimizing the processing conditions.     

Role of muscle endopeptidases and their inhibitors in meat tenderness

Postmortem meat tenderness improvement is generally assumed to result from the softening of the myofibrillar structure by endogenous proteolytic enzymes. In this context, the present paper is a broad overview of the different peptidases so far identified in skeletal muscle, their specific inhibitors and their respective potential role in postmortem muscle. A series of petidase families have been thus considered including calpains, cathepsins, proteasomes, caspases, matrix metallopeptidases (MMP) and serine peptidases.     

肌肉嫩化方法及其机理分析

嫩度是肌肉重要的食用肉品质特征之一,影响肌肉嫩度的因素多种多样,包括肌原纤维、胶原蛋白、内源酶在内的内部因素,和温度、pH值等外部因素。阐述了物理(电刺激、高压处理、超声波)、生物化学(盐类、有机酸和生物酶)处理技术以及多种嫩化方法结合技术改善肌肉嫩度的方法,分析了不同的嫩化机理,并就肌肉嫩化机理分析研究进行了展望。     

基于低场核磁共振技术检测冷鲜滩羊肉的嫩度

以宁夏滩羊肉为研究对象,采用低场核磁共振（LF-NMR）技术研究了冷鲜滩羊肉在贮藏过程中水分分布、迁移情况,与羊肉的品质指标p H、肉色（L*、a*、b*）、剪切力等进行相关性分析。结果发现,LF-NMR测得冷鲜滩羊肉的横向弛豫时间T2谱中出现4个水分群,各水分群对应的横向弛豫时间分别为T20、T21、T22、T23,且与各指标间显著性较高（p<0.05）,其中T2与剪切力相关系数为-0.996,极显著相关（p<0.01）,总峰面积A与剪切力极显著负相关（p<0.01）,相关系数为-0.991。为了进一步研究峰面积A、横向弛豫时间T2与剪切力的关系,建立曲线回归方程进行拟合分析,其峰面积A、横向弛豫时间T2与剪切力回归拟合效果较好,回归系数分别为0.960、0.942。研究结果可为滩羊肉在贮藏过程中嫩度的快速检测提供理论依据。      

超声波处理对结缔组织胶原蛋白和肉嫩度的影响

近年来,有许多研究报道了超声波在肉嫩化中的应用.超声波处理对肉质构的影响主要是由于超声波直接或间接的"空化效应".本文综述了超声波技术在肉类工业中的应用,主要阐述了不同频率和强度超声处理对肉"背景硬度"-肌内结缔组织及胶原蛋白特性的影响;同时,预测了超声波技术在肉类工业中的应用.     

木瓜蛋白酶结合滚揉处理对马肉嫩度的影响

以系水力、蒸煮损失和剪切力为评价指标,结合滚揉处理,研究了木瓜蛋白酶在不同的添加量、p H值、处理温度和处理时间下对马肉嫩度的影响,并利用正交试验优化出了木瓜蛋白酶最佳嫩化条件。实验结果表明:木瓜蛋白酶的添加量、p H值、处理温度和处理时间对马肉的系水力、蒸煮损失和剪切力均有显著的影响;在木瓜蛋白酶的添加量15 U/g,处理温度50℃,p H 6.0,处理时间1 h;或者木瓜蛋白酶添加量为10 U/g,处理温度50℃,p H 6.0,处理时间1.5 h的条件下,添加木瓜蛋白酶均能达到理想的嫩化效果。