Shleikin Alexander G, Medvedev Yaroslav V
Institute of Refrigeration and Biotechnologies, St. Petersburg National Research University of Information Technologies,Mechanics and Optics, Russia.
Moscow Veterinary Clinic, Russia.
Acta Sci Pol Technol Aliment. 2014 Apr-Jun;13(2):123-7. doi: 10.17306/j.afs.2014.2.1.
It is known, that lipid peroxidation is one of the main factors limiting the quality and acceptability of meat and other animal tissues. The current data concerning connection of heme and peroxidation were summarized and analysed here. The muscle food compounds that are most influenced by oxidative processes include unsaturated fatty acids of lipids, amino acids of proteins and heme groups of pigments. Heme proteins and particularly myoglobin are abundant in muscle tissues. Meat colour is primarily influenced by the concentration and chemical State of heme pigments, myoglobin and hemoglobin. Oxygenated myoglobin oxidized to the brown metmyoglobin form and its accumulation is highly correlated with progress of lipid peroxidation. Heme proteins such as hemoglobin or myoglobin accelerate the decomposition of hydroperoxides to free radicals. Metmyoglobin possesses «pseudoperoxidase» activity and catalyzes the oxidation of various compounds following the reaction with hydrogen peroxide. The reaction between hydrogen peroxide and metmyoglobin results in the formation of two active hypervalent myoglobin species, perferrylmyoglobin (·MbFe(IV)=0) and ferrylmyoglobin (MbFe(IV)=0), which participate in lipid oxidation catalysis. Both MbFe(IV)=0 and ·MbFe(IV)=0 are deactivated in the presence of reducing agents, whose nature determines the overall effect of the pseudoperoxidase cycle. Hypothesis can be put forward that loss of cellular antioxidants might precede the rise of peroxidase-like activity, thus being a sign of incipient discoloration of meats and muscle components of foods.
众所周知，脂质过氧化是限制肉类和其他动物组织质量及可接受性的主要因素之一。本文总结并分析了目前关于血红素与过氧化作用之间联系的数据。受氧化过程影响最大的肌肉食品成分包括脂质中的不饱和脂肪酸、蛋白质中的氨基酸以及色素的血红素基团。血红素蛋白尤其是肌红蛋白在肌肉组织中含量丰富。肉的颜色主要受血红素色素、肌红蛋白和血红蛋白的浓度及化学状态影响。氧化肌红蛋白氧化成褐色高铁肌红蛋白形式，其积累与脂质过氧化的进展高度相关。血红蛋白或肌红蛋白等血红素蛋白会加速氢过氧化物分解为自由基。高铁肌红蛋白具有“假过氧化物酶”活性，与过氧化氢反应后催化各种化合物的氧化。过氧化氢与高铁肌红蛋白之间的反应会形成两种活性高价肌红蛋白物种，即过氧亚铁肌红蛋白（·MbFe(IV)=O）和亚铁肌红蛋白（MbFe(IV)=O），它们参与脂质氧化催化。在还原剂存在的情况下，MbFe(IV)=O和·MbFe(IV)=O都会失活，还原剂的性质决定了假过氧化物酶循环的总体效果。可以提出这样的假设，即细胞抗氧化剂的丧失可能先于过氧化物酶样活性的升高，因此是肉类和食品肌肉成分开始变色的一个迹象。
