宰后牛肉色泽稳定性及其影响因素

介绍了宰后影响牛肉色泽稳定性的主要因素及其机理,肌红蛋白的氧化状态是决定鲜肉产品的最主要因素,高铁肌红蛋白还原酶活力对于肌红蛋白氧化状态及肉色稳定性的影响最大,而在宰后储藏过程中各种内源性抗氧化成分对肉色稳定具有重要作用.并建议引入体外孵化和预测模型等相关研究方法.关于影响因子的精确研究对提高肉品色泽品质具有重要意义.     

氧化应激对牛肉肉色及其稳定性的影响研究进展

肉色作为衡量肉品质的关键指标一直是肉品产业关注的焦点。刚屠宰的牛胴体由于缺氧、缺血产生了大量活性氧,活性氧积累造成胴体氧化应激,进一步促进肌红蛋白的氧化,对肉色产生不利影响。但目前关于氧化应激对肉色及肉色稳定性的影响鲜有系统、深入总结。本文综述氧化应激通过调控脂质氧化、蛋白质氧化和降解以及线粒体的功能等途径对肉色及其稳定性的影响,以期为通过控制宰后氧化应激来保持牛肉良好的肉色提供理论依据。     

鲜肉褪色的生化机制研究

肉色是影响消费者购买欲的一个十分重要的特性。肉色的稳定性受到许多因素的影响且极其容易发生变化。一些外源因素如储存、存放条件对肉色稳定性的作用已被大量研究，但肉本身的生化机制对肉色的影响却极少涉及，因此，对这一机制进行综述，为其在肉色稳定方面的应用提供理论依据。     

牛肉肉色的影响因素及其控制技术研究进展

肉色及其稳定性是新鲜牛肉的重要品质指标之一,也是影响消费者选择购买的关键因素。现有研究表明多种因素都会对肉色及其稳定性产生影响。本文综述了在宰前影响机体内抗氧化物质及其浓度的因素(品种、性别、日粮因素和动物管理等)以及宰后因素(成熟时间、不同部位肌肉和肌浆蛋白)对牛肉肉色的影响及其机理,同时总结了部分包装方式、冷杀菌技术(低温等离子体、脉冲电场)和添加外源物对改善牛肉产品肉色及其稳定性的作用。本文可为提高牛肉肉色稳定性和牛肉品质提供相关理论指导。     

钙盐调控牛肉品质因素及其应用的研究进展

嫩度和肉色是影响消费者购买牛肉的两个最重要因素,也直接影响着牛肉品质。为了改善嫩度和肉色等肉品质出现了很多方法,钙盐嫩化法被认为是一种经济实惠而又高效的方法,在适宜的添加量范围内它既可以显著提高肉嫩度,也可以明显改善肉色。然而,现在关于不同钙盐调控牛肉品质改善的机理因素及其应用情况的研究还相对较少,这阻碍了钙盐嫩化法的进一步发展。因此,本文从钙盐添加方式、钙盐调控牛肉品质改善因素和钙盐在牛肉上的应用研究情况三方面进行综述,以期为钙盐在肉制品领域中进一步发展提供借鉴意义。     

基于食品测色仪的肉色变化规律研究

目的 为实现仪器测定肉色的规范化、标准化提供参考依据。方法 采用食品测色仪研究了牛肉、羊肉、猪肉和鸡肉肉色L*、a*、b*、C*、h、L、a、b值随氧合时间及肉块厚度的变化规律。结果 时间方面, 鲜切牛肉在24~28 min, 鲜切羊肉、猪肉在8~12 min内各肉色指标均未发生显著变化(P>0.05), 鸡肉在0~40 min的测定过程中肉色比较稳定; 厚度方面, 牛肉、羊肉厚度由1.5 cm增至2.0 cm过程中肉色变化不显著, 而猪肉厚度增至2.5 cm之前肉色持续变化。结论 食品测色仪测定肉色的适宜条件为: 鲜切牛肉氧合24 min, 厚度不小于2 cm; 鲜切羊肉氧合10 min, 厚度不小于2 cm; 鲜切猪肉氧合10 min, 厚度不小于2.5 cm; 鸡肉不需氧合可直接测定。     

钙盐对肉与肉制品肉色的影响及其机理研究进展

在肉类工业中,钙盐常用于改善生鲜肉的嫩度,或者作为肉制品营养强化剂或低钠肉制品的部分替代盐类应用在肉制品中。但研究发现,钙盐处理在以上应用过程中容易导致肉色的劣变。然而,在目前关于钙盐与肉色关系的研究中,有许多结论存在争议,这可能与钙盐种类、添加剂量、加工方法以及诸多环境因素有关。因此,为进一步明确钙盐对肉色影响的机制和当前的研究进展,本文从钙盐与脂质氧化和高铁肌红蛋白还原活性的关系等方面探讨了钙盐影响肉色的可能机制,并对近年来钙盐对肉与肉制品肉色和肉色稳定性影响的研究进展进行了概述,以期为未来钙盐在肉类工业中的合理应用提供借鉴。     

肉的颜色变化机理及肉色稳定性因素研究进展

对近几十年来人们对肉色化学、鲜肉成色机理的描述,影响肉色稳定性的化学、生物学因素,进行了综述。国际上研究者们对有关肉色的众多相关性指标和因素均存在很大的争议,但肌红蛋白的绝对含量和肌红蛋白的三种不同形式的相对含量,为肉色稳定性的基础已被广泛认可。     

线粒体对肉色及其稳定性影响的研究进展

肉色是评价肉品品质最直观的指标,能够直接影响消费者的购买意愿。近40 年有较多学者对影响肉色及 其稳定性的因素进行了概述,但较少涉及线粒体对肉色及肉色稳定性的影响。线粒体与肌红蛋白的氧化还原状态密 切相关,它主要通过影响氧气消耗和高铁肌红蛋白还原来改变肉色及其稳定性,因此影响线粒体结构和功能的因素 也会影响肉色。本文对目前关于线粒体与肉色及其稳定性关系的研究进行综述,概括线粒体对肉色及其稳定性的直 接影响和基于线粒体影响肉色及其稳定性的因素,并阐述其影响机理。     

牛年时尚牛肴

牛年吃牛，老生常谈，吃款时尚牛肴，清清口味，爽爽雅兴，牛上加牛，方可享受牛年。 牛肉分为黄牛肉和水牛肉两种。黄牛肉色鲜红，膘黄，烹调后肉鲜、味香，汤清；水牛肉色紫红，纤维略粗，膘白，鲜味较差，汤汁不佳，因此中西餐中大都选用黄牛肉。牛肉在西餐烹调又分成牛肉和小牛肉两种。     

Does It Look Cooked? A Review of Factors That Influence Cooked Meat Color

ABSTRACT:  Adequate cooking of meat is necessary to inactivate microbial pathogens. This is particularly important for ground meat products and some variety meats where pathogens can be present internally. Consumers are being advised on appropriate temperatures to which meat products should be cooked, and to use a meat thermometer to ensure these temperatures are reached. However, consumers are more likely to assess cooking status by the color of the meat or juice. This article reviews the factors that can influence the final color of cooked meat. In most instances, these factors influence color by modifying the meat pigment myoglobin prior to and during cooking. Many factors can prolong the pink "uncooked" color in meat, including high pH, modified atmosphere packaging, rapid thawing, low fat content, nitrite, and irradiation. Such factors may lead to overcooking and loss of food quality, and consumer rejection. Alternatively, factors that cause "premature browning" of meat, where the interior of the product looks cooked but a microbiologically safe temperature has not been reached, are food safety issues. Pale, soft exudative meats can prematurely brown, as can meats packaged under oxygenated conditions, frozen in bulk or thawed over long periods, or those that have had salts or lean finely textured beef added. Meats cooked from a frozen state or irradiated in aerobic conditions might also be at risk, but this might depend on meat species. In summary, the color of cooked meat is not a good indicator of adequate cooking, and the use of a food thermometer is recommended.     

Antioxidant Effects of Carnosine and Phytic Acid in a Model Beef System

Antioxidant and color stability effects of carnosine and phytate were compared in a fresh beef model system and in cooked beef. Both compounds increased the rate of pH decline in pre-rigor muscle. Phytate also increased the rate of post-mortem glycogen catabolism. Both antioxidants inhibited metmyoglobin formation in raw samples during storage. Phytate was more effective than carnosine for inhibition of lipid peroxidation. Heme iron content was negatively related to lipid peroxidation in cooked beef (r=–0.92). Phytate was also more effective for inhibition of iron release from heme during cooking. Phytate is recommended over carnosine as an effective antioxidant in cooked meats.     

影响低温肉制品褪色因素研究进展

低温肉制品在贮藏过程中易褪色,是由主导色素亚硝酰血色原氧化引起的。原料肉来源、蒸煮温度、滚揉和烟熏等工艺均对低温肉制品颜色有影响。光照和氧气直接导致了色素氧化,进而引起褪色,适宜的冷藏温度和气调包装能减缓色素氧化并保护产品颜色。添加剂如亚硝酸盐、抗氧化剂和色素对低温肉制品颜色有不同程度的影响。     

Thawing Prior to Cooking Affects Sensory, Shear Force, and Cooking Properties of Beef Patties

Patties from 6 commercial formulations were cooked to 71°C from either the frozen state or after thawing for 24 to 27 h at 4 °C to eliminate the pink/red color exhibited when cooked to 71 °C from the frozen state. Thawed patties had shorter cooking times, higher cooking yields, and lower shear force peak load and peak energy values. Patties cooked from the thawed state increased in thickness during cooking, while patties cooked from the frozen state decreased in thickness during cooking. Thawing prior to cooking increased sensory evaluation scores except for patties made with carrageenan. Thawing not only eliminated the problem of pink/red color after cooking but also improved sensory, shear force, and cooking properties of beef patties.     

Cooked Color in High pH Beef Patties as Related to Fat Content and Cooking from the Frozen or Thawed State

Beef patties were processed from high pH (>6.0) beef to contain 5, 10, 15, 20 or 25% fat. Patties were cooked to 71°C from the frozen or thawed state before evaluating color. Neither fat content nor state of patties when cooked exerted any major influence on color, but linear effects (p<0.01) in association with increased fat content included higher L* values and hue angles and lower a* values (15.2% reduction). Higher values for L*, b* (but not for 5% fat patties), and hue angles were observed for patties cooked thawed rather than frozen. The use of high pH beef lessened the effects of increased fat and cooking from the thawed state on increased brown color in cooked patties.     

Cookery method and end-point temperature can affect the Warner-Bratzler shear force, cooking loss, and internal cooked color of beef longissimus steaks

Steaks from 60 beef ribeye rolls were used to test the interactive effects of cookery method and end-point temperature on Warner-Bratzler shear force (WBSF) and internal cooked color. Pairs of longissimus thoracis (LT) steaks were assigned to combinations of 3 different end-point temperatures and 5 cookery methods. The forced-air convection oven (FAC) required the longest time and produced the reddest internal color, regardless of end-point temperature. The clam-shell grill (CLAM) required the least cooking time and resulted in the lowest cooking losses, but CLAM-cooked steaks also had the greatest WBSF values and least red internal color. Repeatability values for WBSF were acceptable (>0.60) for all degrees of doneness when steaks were cooked in the FAC and impingement oven, but steaks cooked on the CLAM were not repeatable. The relationship of myofibrillar toughening, moisture loss and cooked color changes in beef LT steaks also differed due to cookery methods.     

Comparison of Color and Thiobarbituric Acid Values of Cooked Hamburger Patties after Storage of Fresh Beef Chubs in Modified Atmospheres

ABSTRACT: Cooked meat color is an important quality attribute for consumers. This study compared color and thiobarbituric acid (TBA) values of cooked ground beef (internal temperatures of 49 to 79 °C), after storage of raw product in atmospheres of 0.4% carbon monoxide (CO), 80% oxygen, or vacuum at 2 °C for 7 to 21 d. Premature browning, observed as a brown cooked color at internal temperatures as low as 49 °C, was found in patties made from meat stored in 80% oxygen. At all cooking temperatures, samples stored in high oxygen had less internal red color, higher myoglobin denaturation values, and were more rancid with higher TBA values than CO or vacuum-packaged ground beef. Raw ground beef held in 0.4% CO modified-atmosphere packaging (MAP) remained bright red throughout the 21-d storage period. Premature browning and high TBA values in cooked patties were avoided by use of this packaging system. However, internal patty color remained somewhat red even at the highest internal cooking temperature of 79 °C. The persistent pink color observed in CO-treated patties cooked to 79°C internal temperature was likely due to development of heat-denatured CO-hemochrome, rather than the presence of undenatured CO myoglobin. The problems of PMB and high TBA values of cooked patties were also avoided by vacuum packaging. However, the development of dark purple color associated with vacuum packaging of raw beef limits the use of this packaging method for products in retail display. Keywords: beef, packaging, carbon monoxide, oxygen     

RELATIONSHIPS AMONG CHEMICAL, COOKING AND COLOR PROPERTIES OF BEEF PATTIES COOKED TO FOUR INTERNAL TEMPERATURES

A study involving five laboratories and nationwide sampling of ground beef was undertaken to determine cooking and color properties of patties cooked to 52.7, 65.6, 71.1 and 79.4C. The design of the study included purchase location (local, distant) and patty handling prior to cooking Pesh, thawed either as patties or bulk ground beef). Purchase location was not a statistically significant influence on cooking and color properties. Patties processed from bulk thawed product had a higher amount of brown cooked color. A strong relationship existed between visual and instrumental measures of red color in cooked patties. However, correlations among other cooking properties were low. Patties with higher fat content were associated with shorter cooking times, lower cooking yields and more brown cooked color. The low relationships between raw and cooked patty properties limits the use of raw ground beef properties as predictors of food safety in cooked beef patties. This further supports the use of instant read meat thermometers in cooking beef patties to at least 71C.     

Visual color and doneness indicators and the incidence of premature brown color in beef patties cooked to four end point temperatures

An interlaboratory study was undertaken to assess the frequency that cooked color of ground beef patties appeared brown at internal temperatures of 52.7 degrees C (135 degrees F), 65.6 degrees C (150 degrees F), 71.1 degrees C (160 degrees F), and 79.4 degrees C (175 degrees F). In general, as internal cooked temperature of the patties increased, the following results were observed in the patties: (i) more brown meat color, (ii) less pink or red juice color, and (iii) more cooked texture. However, brown meat color occurred prematurely at the two lower internal temperatures (57.2 degrees C/135 degrees F and 65.6 degrees C/150 degrees F) that are insufficient to eliminate foodborne pathogens without holding times. The common consumer practice of freezing bulk ground beef, followed by overnight thawing in a refrigerator, led to substantial premature brown color in patties cooked from this product. In addition, at 71.1 degrees C (160 degrees F), recognized to be the lowest temperature for cooking ground beef safely in the home, meat color, juice color, and texture appearance were not fully apparent as doneness indicators. In fact, at no temperature studied did 100% of the patties appear done when evaluated by the criteria of no red or pink in the meat, no red or pink in the juices, or by texture appearance. Patties in this study were evaluated under a set protocol for forming the products, cooking, and viewing under the same lighting conditions. Other preparation conditions are possible and may produce different results. Thus, temperature to which patties have been cooked cannot be judged by color and appearance. This study provided the evidence to support the message to consumers regarding cooking of beef patties of "use an accurate food thermometer and cook beef patties to 160 degrees F (71.1 degrees C)" in place of messages based on consumer judgment of cooked color.     

FACTORS AFFECTING COLOR PROPERTIES OF BEEF PATTIES COOKED ON AN OUTDOOR GAS GRILL

Visual and instrumental color properties were obtained on beef patties cooked on an outdoor gas grill. Factors evaluated as to their influence on color were fat content, (20–28% vs 6–10%) patty handling prior to cooking (fresh, thawed either as patties or bulk ground beef), endpoint in cooking (57, 66, 71C, slit in outer edge of patty during cooking showing brown color), lighting conditions and evaluation time post-cooking. Factors resulting in less pink/red color and more brown color in cooked patties were (1) higher fat content, (2) cooking bulk frozen, thawed, then pattied product, (3) higher endpoint temperature and longer time postcooking before evaluation. Termination of cooking by observing brown color in slits in patties cooked on a gas grill was not synonymous with a safe internal temperature.