Myoglobins: the link between discoloration and lipid oxidation in muscle and meat

Abstract

Recebido em 9/1/05; aceito em 9/12/05; publicado na web em 6/7/06Aerobic metabolism changes rapidly to glycolysis post-mortem resulting in a pH-decrease during the transformation of muscle in to meat affecting ligand binding and redox potential of the heme iron in myoglobin, the meat pigment. The "inorganic chemistry" of meat involves (i) redox-cycling between iron(II), iron(III), and iron(IV)/protein radicals; (ii) ligand exchange processes; and (iii) spin-equilibra with a change in coordination number for the heme iron. In addition to the function of myoglobin for oxygen storage, new physiological roles of myoglobin are currently being discovered, which notably find close parallels in the processes in fresh meat and nitrite-cured meat products. Myoglobin may be characterized as a bioreactor for small molecules like O 2 , NO, CO, CO 2 , H 2 O, and HNO with importance in bio-regulation and in protection against oxidative stress in vivo otherwise affecting lipids in membranes. Many of these processes may be recognised as colour changes in fresh meat and cured meat products under different atmospheric conditions, and could also be instructive for teaching purposes.

Colour modification in a cured meat model dried by Quick-Dry-Slice process® and high pressure processed as a function of NaCl, KCl, K-lactate and water contents

“…autoxidation is not sensitive to changes in ionic strength as caused by salt addition (Møller & Skibsted, 2002;2006). The addition of K-lactate (25.6 g/kg) did not have a significant effect on colour parameters or on the dependence of colour on water content either.…”

Master bag low-oxygen packaging system: Quality evolution of ground beef patties during storage, blooming and display presentation

“…A link between protein and lipid oxidation consisting of the reciprocal induction of these two phenomena has been shown (Baron & Andersen, 2002;Møller & Skibsted, 2006); therefore, lipid oxidation is expected to occur during aerobic storage (i.e., display life). To verify this hypothesis, TBARs analysis was carried out.…”

Nitroso-Hemoglobin Preparation and Meat Product Colorant Development

“…The fundamental knowledge of Mb chemistry is therefore, crucial, and the "inorganic chemistry" of meat had to include a quantitative accurate description of Mb complicated formation with small ligands, such as O 2 , NO, H 2 O and CO, and the kinetics of transformations of these complexes under transforming conditions of temperature, oxygen pressure, pH, ionic strength and light exposure. The practical aspect of colour solidity of meat and meat products in the meat industry and retail trade has started abundant examinations over the last 50 years and significantly an increased understanding of the complicated chemistry [30]. The detection of the physiological momentousness of NO and the quite possible function of hypervalent Mb and Hb throughout the oxidative stress possess added new perspectives to the dynamic description of electron transfer and ligand exchange reactions of these heme pigments [31].…”

“…Additional significant functions of Mb than oxygen conveyance and storage seem to be important, and these in vivo important functions contain activity as a pseudo-enzyme in quite specific muscle tissue similar to NO dioxygenase clearly recognized from microorganisms. In effect, Mb characterizes as a cellular defender against nitrosamine stress during excess production of NO [30]. Future investigation is supposed to focus on the role of Mb as a mediator of responses between small molecules most important as bio-regulators and contain researches of reaction dynamics hopefully happening within the protein structure using time-resolved spectroscopy [30].…”

“…In effect, Mb characterizes as a cellular defender against nitrosamine stress during excess production of NO [30]. Future investigation is supposed to focus on the role of Mb as a mediator of responses between small molecules most important as bio-regulators and contain researches of reaction dynamics hopefully happening within the protein structure using time-resolved spectroscopy [30]. called denatured metmyoglobin is shaped, which normally cannot be transformed to another pigment.…”