滚揉法、氯化钙法与木瓜蛋白酶对羊肉嫩化效果的比较研究

优选出滚揉法、氯化钙法和木瓜蛋白酶对羊肉嫩化的最适条件,研究了3种嫩化方法对羊肉的嫩化效果.研究结果表明:滚揉嫩化的最适条件为:滚揉60min,滚揉后在10℃的条件下放置8h;氯化钙嫩化的最佳条件为:在羊肉中注射2%的CaCl2 溶液(400m mol),滚揉30min后,在10℃条件下放置8h;木瓜蛋白酶的最佳嫩化条件为:在羊肉中注射木瓜蛋白酶,滚揉30min,然后在10℃的条件下放置8h.羊肉中添加0.005%的木瓜蛋白酶的嫩化效果优于其它两种,其次是氯化钙法.     

低温肉制品关键工艺及装备技术应用研究进展

低温肉制品是我国肉制品发展的趋势,其产品的加工品质如蒸煮得率、系水性、质构特性及感官品质受滚揉、机械嫩化、盐水注射、斩拌等机械处理的影响。本文综述机械处理在低温肉制品生产中的应用现状。低温真空滚揉能缩短腌制时间,改善产品质构,目前国内外广泛采用;充气变压滚揉比低温真空滚揉具有一定的优势,产品的质构、持水性和出品率相对较高,且抑菌效果较优;预滚揉处理往往与其他处理相结合可减少总滚揉时间,改善腌制液渗透,提高产品得率;机械嫩化能破坏肌肉组织结构,降低产品剪切力值,改善感官嫩度;盐水注射能加快腌制液的渗透,增加产品出品率,腌制液中的成分、浓度及注射率影响产品品质;斩拌终温显著影响乳化产品品质。     

弹性蛋白酶嫩化卤牛肉的工艺研究

采用弹性蛋白酶和复合磷酸盐为嫩化剂,选用工程法速溶调味料和真空滚揉技术,开发了嫩化性卤牛肉生产新工艺。通过正交试验设计和对卤牛肉持水性测定及感官评定,确定卤牛肉嫩化的较优工艺参数为:弹性蛋白酶用量为0.001%,溶液注射量为15%,滚揉时间为20-30min,滚揉间歇时间10min,腌制时间为6h,煮制时间15min。     

关于肉食品生产中的几个实际问题

目前西式肉食品加工中比较先进的生产工艺是采用真空解冻或高压解冻、盐水注射、滚揉、酶法嫩化等,被最多采用的是盐水注射和滚揉。但就注射设备来讲,常常达不到预期的效果。把滚揉作为腌制的全过程有时腌不透,难以达到要求的呈色效果,而且耗时长,不利规模化生产。解决这个问题     

茶风味牛肉干

以新鲜牛肉为原料,经过修整,注射腌制液,滚揉按摩,然后腌制,分割,烤制,出炉后冷却包装即成嫩化型的茶味牛肉干。探讨了CaCl2添加量、西式工艺滚揉按摩和茶粉对牛肉干品质的影响。结果表明注射占注射液2%的CaCl2水溶液,进行嫩化,结合30分钟内揉4分钟停2分钟的滚揉按摩,均匀涂布上速溶茉莉花茶粉进行烘烤,制得的牛肉干品质最佳,与传统方法进行比较其出品率也非常高,具有独特的风味和简单的工艺流程,在工业化生产方面具有广阔的应用前景。     

不同处理对新疆羊半腱肌嫩度的影响

目的:寻求一种成本低、安全健康、嫩化效果好的嫩化方法。方法:以剪切力、pH值、蒸煮损失、肌原纤维小片化指数(myofibrillar fraglllentation index,MFI)、胶原蛋白含量及其溶解度、羊半腱肌全骨架蛋白降解情况等为评价指标,研究腌制结合滚揉、真空滚揉及腌制结合真空滚揉对羊肉嫩度的影响。结果表明:3种处理对羊肉的剪切力、pH值、蒸煮损失、肌原纤维小片化指数均影响显著。结论:采用真空滚揉对羊肉嫩化效果最佳。     

注射-滚揉工艺对鸡腿制品品质的影响

各种机械处理会影响肉制品的品质,其中注射和滚揉是鸡腿制品加工过程中两个最重要的机械处理方式。实验以出品率、保水性、嫩度、质构为评价指标,研究鸡腿重量、注射率、滚揉时间对鸡腿制品品质的影响。结果表明,加工鸡腿过程中可以通过调节鸡腿重量、注射率、滚揉时间来提高产品出品率,并确保产品适宜的保水性和嫩度。当注射率较低时,以15%±2%的注射率为例,滚揉时间在0～4h内对鸡腿制品的滚揉出品率和产品出品率影响显著,鸡腿重量也有影响;当注射率较高时,以25%±2%的注射率为例,滚揉时间和鸡腿重量对鸡腿品质影响不显著。     

一种冷冻调理猪肉的加工工艺研究

采用高压注射渗透、低温滚揉嫩化等技术的冷冻调理猪肉制品,具有安全、营养、美味的特点,解决了生鲜肉配送难、保质期短等问题。     

冷冻调理猪肉的加工工艺

采用高压注射渗透、低温滚揉嫩化等技术的冷冻调理猪肉制品,具有安全、营养、美味的特点,并解决了生鲜肉配送难、保质期短等问题.     

西式肉制品主要加工技术研究

为更好地推动西式肉制品加工技术在肉制品加工中的应用发展,介绍了低温腌制技术、盐水注射技术、真空滚揉技术、嫩化技术、栅栏技术、烟熏技术6种常用的西式肉制品主要加工技术。主要论述了低温腌制技术、盐水注射技术、真空滚揉技术、嫩化技术、栅栏技术、烟熏技术这6种主要加工技术的特点和作用,同时阐述了在各类肉制品加工中的相关研究以及在肉制品加工生产与研究中的相关应用,并浅谈了6种加工技术的研究展望,以期为今后的肉制品加工研究提供一些方向。     

Optimisation of tenderisation, ageing and tenderness

Tenderness is an important part of meat acceptability and is affected by variations in production and processing. The tenderisation process was modelled on the activity of calpain proteinases. The extent of tenderisation is proportional to the level of calpains which accounts for the toughness of meat from β-adrenergic agonists. The rate of tenderisation increases with higher temperature and faster rigor development. These are responsible for the faster tenderisation in chicken, in meats following the use of electrical stimulation and in meats of high ultimate pH. Knowledge of these mechanisms of tenderisation afforded processes for optimisation of tenderness.     

Calpain-calpastatin and toughness in M. longissimus from electrically stimulated lamb and beef carcasses

Shear strength, pH, temperature, μ-calpain, m-calpain and calpastatin levels were measured over a two-week post-slaughter period in Longissimus lumborum et thoracis (LD) from six lamb and six beef carcasses. All carcasses were subjected to high voltage electrical stimulation. The toughness of the beef LD determined by a MIRINZ tenderometer at 24 h post-slaughter showed a strong correlation (r=0.91) with pH of the LD at 3 h. Beef LD toughness at 14 days was correlated (r=0.84) with initial m-calpain levels. In both lamb and beef, LD toughness at 4 and 14 days respectively was also correlated with initial levels of calpastatin (r=0.85, 0.83, respectively). The strong correlation between calpastatin and the rate of tenderisation indicates that the calpain system is closely linked to the proteolytic breakdown of myofibrillar proteins. There is also evidence of an interaction between pH and μ-calpain activity. The μ-calpain, m-calpain, calpastatin, pH and temperature kinetic changes which occurred during the post-mortem ageing of beef and lamb LD were applied to a computer program which predicted rate of meat tenderisation by calculating in situ calpain activity. The closeness of fit between the predicted rate of meat tenderisation and the observed tenderness values of beef and lamb LD indicates that the post-mortem activity of μ-calpain is the major determinant of variations in tenderness. However, application of the meat tenderisation predictive program to LD from individual animals revealed that the program was not sufficiently robust for this use.     

Modelling post-mortem tenderisation-III: Role of calpain I in conditioning

A simple model is developed to show how proteolysis by calpain I can account for the variations in tenderness in electrically stimulated and nonstimulated beef pectoralis profundus muscles stored between 0°C and 30°C. As the pH of the muscle falls to about 6·1, calpain I is activated and causes proteolysis and tenderisation. The rate of tenderisation is then proportional to the concentration of calpain I which is autolysed slowly reducing its concentration and the rate of tenderisation. The activation energy for the inactivation (autolysis) of calpain I is slightly higher than that for its activity in tenderisation (proteolysis) and therefore, at higher temperatures, less tenderisation occurs. Proteolysis and tenderisation continue at a rate governed by the concentration of calpain I and the temperature until calpain I is depleted when tenderisation stops. Parameters for the activity and inactivation of calpain I were derived and were shown to predict 68% of the variation in toughness.     

Advances in apoptotic mediated proteolysis in meat tenderisation

Meat tenderness is considered to be one of the most important attributes of meat quality; however it is also one of the most variable. Ultimate meat tenderness is influenced by the amount of intramuscular connective tissue, the length of the sarcomere and also the proteolytic potential of the muscle. Post-mortem proteolysis by endogenous proteases causes the weakening of myofibril structures and associated proteins, which results in tenderisation. The caspase proteolytic system was first identified to be a potential contributor to post-mortem proteolysis and tenderisation in 2002. Since then research has both supported and challenged this hypothesis. The purpose of this review is to examine the experimental evidence available for caspases' involvement in post-mortem proteolysis, and to highlight cross-talk between this proteolytic system and the calpain system, a known contributor to meat tenderisation.     

Should electrical stimulation be applied when cold shortening is not a risk?

This experiment was designed to show whether delayed high voltage stimulation (ES) is more beneficial than no stimulation (NS) to secure tenderness under circumstances where rigor conditions are difficult to control due to variations in carcass size, fatness and/or chilling capacity. Ten Charolais carcasses were split during slaughter, the left sides were stimulated at 45 min post-mortem for 45 s, and the right sides were left unstimulated. The carcass sides were then chilled at a medium chilling rate. Sarcomere length measurements confirm that there was neither cold nor heat shortening in the M. longissimus (LD). LD from ES sides aged for 2 days was more tender than non-stimulated LD (NES), although prolonged ageing eroded the advantage of ES to a non-significant advantage after 14 days. Initial tenderness differences coincided with lower 24 h calpain activity, suggesting an early onset of proteolysis and ageing (tenderisation). In contrast to conventional early ES, delayed ES, appears to be beneficial for the early development of tenderness without too much interference with enzyme. Myofibril fragment length (MFL) was a good indicator of the development of tenderness during prolonged ageing but not for the early post-mortem variation in tenderness. No colour (L*, a*, b*) differences, occurred due to stimulation treatment, while drip loss was slightly higher at 24 h post-mortem for ES meat.     

电刺激对牛背最长肌中钙激活酶活性及嫩度的影响

通过对中国杂交黄牛(鲁西黄牛×西门塔尔)牛背最长肌中Calpains活性及剪切力值的分析,研究了电刺激对牛背最长肌宰后成熟过程中Calpains活性及牛肉嫩度的影响。结果表明:电刺激显著提高了μ-calpain的活性(P<0.05),降低了calpastatin对μ-calpain的抑制作用,提高了牛背最长肌的嫩度,缩短了牛肉的成熟时间;但电刺激仅在宰后成熟1h,显著提高了m-calpain的活性(P<0.05);宰后成熟24h、3d,与对照组之间差异不显著(P>0.05),试验结果证实,电刺激通过对Calpains体系的影响,改变了牛肉的成熟速度,显著的改善了牛肉的嫩度。     

Low voltage electrical stimulation of lamb carcasses: effects on meat quality

The effects of an early post mortem low voltage electrical stimulation (28 V, 60 Hz) on biochemical changes and on final tenderness in muscles Longissimus thoracis et lumborum and Semimembranosus from lamb carcasses were studied. It was shown that electrical stimulation accelerated the glycolytic process resulting in a significant fall in pH during the first 6 h post mortem in both muscles examined and in a significant reduction in adenosine triphosphate (ATP) content in muscle Longissimus thoracis et lumborum. The effect of electrical stimulation on tenderness was recorded by measuring shear force values 2 and 7 days post mortem. Tenderness was significantly improved by electrical stimulation for the Longissimus thoracis et lumborum both at 2 and at 7 days post mortem, while for Semimembranosus electrical stimulation significantly increased tenderness just at 7 days post mortem.     

The roles of the proteasome, and cathepsins B, L, H and D, in ostrich meat tenderisation

As very little research has been conducted on ostrich meat tenderisation, this study aims at investigating the roles of the proteasome and cathepsins B, L, H, and D in the tenderisation process. The enzyme activities in meat from eight ostriches during a 12-day ageing period and the corresponding physical characteristics (e.g. pH, shear force) and myofibril patterns were determined. After 12 days, substantial high remaining activities were found, especially of the proteasome, thus implicating their possible roles in the tenderisation process. The mean shear force values, however, showed no improvement in tenderness, but the myofibril patterns showed the appearance of a M(r) 32 K component. Myofibril degradation studies of the proteasome, analysed electrophoretically, also revealed a possible role of the proteasome, but under activating conditions. This study provides further insights into the tenderisation process, particularly of ostrich meat, which may ultimately be used for the advantageous manipulation of the process.     

Effect of electrical stimulation on protease activity and tenderness of M. longissimus from cattle with different proportions of Bos indicus content

The effect of electrical stimulation on protease activity (at approx. 3 h postmortem), sensory tenderness scores and shear force was determined on M. longissimus samples from three Bos indicus genotypes (0% Hereford, 50% Brahman×Hereford and 100% Brahman). The samples were divided and aged for 1 or 30 days. Electrical stimulation resulted in a general reduction in calpastatin activity suggesting that it accelerated proteolysis. Calpastatin activity increased commensurate with increasing Bos indicus content. Several significant interactions were shown, the most relevant of these was the interaction between Bos indicus content×electrical stimulation. In contrast to the other genotypes, calpain I and calpain II activities were shown to increase (significant for calpain II only) following stimulation in the purebred Brahmans (100%). There was a significant reduction in tenderness with increasing Bos indicus content. However, breed differences in shear force were reduced by electrical stimulation. The improvement in shear force following ageing was smaller for stimulated carcasses compared to the controls. This tends to reinforce the premise that electrical stimulation accelerates proteolysis. The results of this study show clear genotypic differences in proteolytic activity and tenderness. However, electrical stimulation can be employed to reduce breed differences in tenderness of the M. longissimus.     

宰后电刺激与肉的嫩度

本文综述了电刺激的发展历史背景和研究现状,肌肉的嫩化机制及宰后电刺激促进嫩化的机理.同时,介绍了一些该领域的相关研究成果,并对电刺激的机理和电刺激在动物宰后肌肉嫩化中的应用进行了讨论.