Research Accomplishment Reports 2011

Species-specificity in Carboxymyoglobin Redox Stability

S.P. Suman
Department of Animal and Food Sciences

 

Non-Technical Summary

Maintaining the cherry-red color of red meats using carbon monoxide modified atmosphere packaging is approved in the US. Lipid oxidation compromises meat color, and meat discoloration results in revenue loss to our farm economy. While species-specific nature of lipid oxidation-induced discoloration in oxymyoglobin (cherry-red pigment in conventionally bloomed meat) has been widely investigated, this possibility has not been examined in carboxymyoglobin (cherry-red meat pigment under carbon monoxide modified atmosphere packaging).

Understanding how lipid oxidation affects the stability of carboxymyoglobin from red meats such as beef, pork, and lamb will provide critical information on the color shelf-life of these red meats retailed in carbon monoxide modified atmosphere packaging. In addition, this would contribute to engineering species-specific antioxidant strategies for reducing discoloration-induced sales loss of US meat industry.

2011 Project Description

Oxymyoglobin and carboxymyoglobin are the ferrous redox forms of myoglobin responsible for the consumer-desirable cherry-red color for fresh meats. Oxidation of oxymyoglobin and carboxymyoglobin to brown metmyoglobin is accelerated by lipid oxidation and is associated with meat discoloration, leading to price discounts.

Annually United States meat industry incurs a revenue loss of more than $1 billion as a result of discoloration-induced price discounts.

Our recent investigations using horse myoglobin revealed that both carboxymyoglobin and oxymyoglobin undergo lipid oxidation-induced oxidation in model systems. Previous studies reported that lipid oxidation-induced oxymyoglobin oxidation is species-specific; beef oxymyoglobin is more susceptible to lipid oxidation than pork oxymyoglobin.

However, the species-specific nature of lipid oxidation-induced carboxymyoglobin oxidation has not been investigated. This fundamental study was initiated in late 2010, with the objective to elucidate the species-specific effects of lipid oxidation on carboxymyoglobin from beef, pork, and lamb. The methods to prepare 100% carboxymyoglobin in conditions relevant to meat processing have been standardized. Myoglobin from beef, pork, and lamb are not available commercially and, therefore, are currently being isolated from beef, pork, and lamb muscle tissues.

2011 Impact

Meat color is the most important quality trait governing consumers' purchase decisions at the point-of-sale. Maintaining myoglobin in its cherry-red redox state (carboxymyoglobin or oxymyoglobin) is critical to consumer acceptance of red meats. While cherry-red color of carboxymyoglobin is more stable than oxymyoglobin, discoloration has been reported in red meats retailed under carbon monoxide containing modified atmosphere packaging due to lipid oxidation-induced carboxymyoglobin oxidation.

Characterizing the molecular interactions between lipid oxidation and carboxymyoglobin in different red meats (beef, pork, and lamb) will be beneficial for meat industry and regulatory agencies to clearly define the color shelf-life and the Best Before Date of CO-treated red meats.

2011 Publications

Suman, S.P.; Mancini, R.A.; Joseph, P.; Ramanathan, R.; Konda, M.K.R.; Dady, G; Yin, S. 2011. Chitosan inhibits premature browning in ground beef patties. Meat Science, 88: 512-516.

Joseph, P.; Suman, S.P.; Li, S.; Claus, J.R.; Fontaine, M.; Steinke, L. 2011. Primary structure of turkey myoglobin. Food Chemistry, 129: 175-178.

Nair, M.N.; Joseph, P.; Li, S.; Girish, P.S.; C.M. Beach.; Suman, S.P. Lipid oxidation-induced oxidation in ratite myoglobins. American Meat Science Association Annual Reciprocal Meat Conference, June 2011, Manhattan, KS. Abstract # 114.

Joseph, P.; Suman, S. P.; Li, S.; Fontaine, M.; Steinke, L. Biochemical characterization of white-tailed deer myoglobin. American Meat Science Association Annual Reciprocal Meat Conference, June 2011, Manhattan, KS. Abstract # 112.