Gorelik S, Kanner J
Department of Food Science, Institute for Technology and Storage of Agricultural Products, Agricultural Research Organization, P.O. Box 6, Bet Dagan 50250, Israel.
J Agric Food Chem. 2001 Dec;49(12):5939-44. doi: 10.1021/jf0104578.
Oxymyoglobin is the main pigment in muscle tissues, responsible for the bright red color of fresh meat. Oxidation of the heme iron from the ferrous to the ferric metmyoglobin produces the brownish color that consumers find undesirable in fresh meat. The aim of this study was to elucidate the mechanism of oxymyoglobin oxidation in muscle tissues by using a model system containing oxymyoglobin and muscle membranes oxidized by an iron redox cycle. Oxidation of oxymyoglobin was determined from the decrease in absorption of the solution measured by a spectrophotometer at 582 nm. Lipid peroxidation was determined by accumulation of TBARS and conjugated dienes. The higher rates of oxidation of oxymyoglobin (20 microM) and lipid oxidation were achieved by using ferric iron and ascorbic acid at concentrations of 50 and 200 microM, respectively. Increasing the concentration of ascorbic acid to 2000 microM switched its effect to antioxidative. Increasing the concentration of oxymyoglobin from 20 to 80 microM inhibited lipid peroxidation by >90% and partially prevented oxymyoglobin oxidation.
氧合肌红蛋白是肌肉组织中的主要色素，它赋予鲜肉鲜艳的红色。血红素铁从亚铁状态氧化为高铁肌红蛋白会产生褐色，而消费者不希望在鲜肉中看到这种颜色。本研究的目的是通过使用一个包含氧合肌红蛋白和经铁氧化还原循环氧化的肌肉膜的模型系统，阐明肌肉组织中氧合肌红蛋白的氧化机制。通过分光光度计在582nm处测量溶液吸光度的降低来测定氧合肌红蛋白的氧化。通过硫代巴比妥酸反应物（TBARS）和共轭二烯的积累来测定脂质过氧化。分别使用浓度为50μM和200μM的三价铁和抗坏血酸时，可实现较高速率的氧合肌红蛋白（20μM）氧化和脂质氧化。将抗坏血酸浓度增加到2000μM时，其作用转变为抗氧化。将氧合肌红蛋白浓度从20μM增加到80μM可抑制脂质过氧化>90%，并部分防止氧合肌红蛋白氧化。
