Biochemical study of rapid discolouration mechanisms in Bison meat

野牛肉快速变色机制的生化研究

• 批准号: RGPIN-2016-06006
• 负责人: RodasGonzalez, Argenis
• 金额: $ 1.82万
• 依托单位: University of Manitoba
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=709792
• 关键词: Biochemical; study; rapid; discolouration; mechanisms

Fresh meat colour is an important attribute used by consumers as an indicator of freshness and wholesomeness, and any deviation of normal colour (e.g. cherry red) is indicative of poor functionality and possible spoilage. Meat colour stability is one of the major concerns in the bison industry, because it is darker and discolours more rapidly than beef under aerobic retail packaging. Consequently, the long-term objective is to gain comprehensive understanding of factors determining myoglobin oxidation/reduction in different bison muscles during storage and retail display under diverse packaging, by monitoring objective and subjective colour changes. The short-term objectives are: 1) to examine the effect of 4-hydroxy-2-nonenal (HNE), protein oxidation, non-heme iron, and the sarcoplasmic proteome on the colour stability of two bison muscles of diverse stability during storage; 2) to establish the relationship among biochemical components, oxidative stability and sarcoplasmic proteins to the oxidation of myoglobin during storage of two bison muscles; 3) to test the ability of near infrared reflectance spectroscopy (NIRS) to segregate bison muscles with stable vs. unstable colour; 4) to determine the effects of carbon monoxide modified atmosphere packaging (CO-MAP) on biochemical components and retail display characteristics of bison steaks from with different colour stability using different storage periods. The redox biochemistry of myoglobin in post-mortem skeletal muscles is particularly complex, where small biomolecules occur that can cause rapid pigment oxidation and surface discolouration; but, their mechanisms of action are not well understood. The higher polyunsaturated fatty acid content in bison could promote oxidation and generate reactive secondary oxidation products such as HNE, and accelerate myoglobin oxidation. This process could involve protein oxidation during refrigerated storage, breakdown of the heme molecule and the subsequent release of non-heme iron from the porphyrin ring, which might also increase oxidative instability in the meat system. Also, variations in the balance between antioxidant/pro-oxidant component proteins (e.g. thioredoxin) in the sarcoplasm could induce lipid oxidation and cause meat discoloration. These measures will be used along with NIRS in order to enable development of colour stability in tissue and apply muscle-specific processing strategies such as novel packaging (e.g. CO-MAP) for improving retail colour stability. Certainly, with better understanding of the factors that determine colour stability, industry can expand fresh meat sales, offering a more consistent, acceptable and desirable product to consumers. In addition, three undergraduate and two M.Sc. students will be trained under my program. The experiences gained with bison could be applicable to other species and mitigate their colour issues.

鲜肉的颜色是消费者用来衡量新鲜度和健康状况的一个重要指标，任何偏离正常颜色（如樱桃红）的情况都表明功能性差，可能变质。肉色稳定性是野牛行业的主要关注点之一，因为它比有氧零售包装下的牛肉颜色更深，变色更快。因此，长期目标是通过监测客观和主观颜色变化，全面了解不同野牛肌肉在不同包装下储存和零售展示期间肌红蛋白氧化/还原的决定因素。短期目标是：1）研究4-羟基-2-壬烯醛（HNE）、蛋白质氧化、非血红素铁和肌浆蛋白质组对两种不同稳定性的野牛肌肉在贮藏过程中颜色稳定性的影响，2）建立生化成分、氧化稳定性和肌浆蛋白质与两种野牛肌肉在贮藏过程中肌红蛋白氧化的关系; 3）测试近红外反射光谱（NIRS）分离具有稳定与不稳定颜色的野牛肌肉的能力; 4）确定一氧化碳气调包装（CO-MAP）的效果不同颜色稳定性的野牛肉排在不同贮藏期内的生化成分和零售陈列特性。死后骨骼肌中肌红蛋白的氧化还原生物化学特别复杂，其中发生小生物分子，可引起快速色素氧化和表面变色;但是，它们的作用机制尚未完全了解。野牛中较高的多不饱和脂肪酸含量可促进氧化反应，产生活性次级氧化产物HNE，加速肌红蛋白氧化。这一过程可能涉及冷藏过程中蛋白质的氧化、血红素分子的分解以及随后从卟啉环中释放出非血红素铁，这也可能增加肉类系统中的氧化不稳定性。此外，肌浆中抗氧化剂/促氧化剂组分蛋白（例如硫氧还蛋白）之间的平衡变化可诱导脂质氧化并导致肉变色。这些措施将与NIRS一起沿着，以便能够开发组织中的颜色稳定性，并应用肌肉特异性处理策略，例如新型包装（例如CO-MAP），以改善零售颜色稳定性。当然，通过更好地了解决定颜色稳定性的因素，行业可以扩大鲜肉销售，为消费者提供更一致，更可接受和更理想的产品。此外，三名本科生和两名硕士生将在我的项目下接受培训。从野牛身上获得的经验可以适用于其他物种并减轻它们的颜色问题。