Reactivity of sulphur dioxide in comminuted meat

Abstract

The factors which determine the instantaneous irreversible binding of sulphur dioxide when sodium metabisulphite is added to comminuted meat are considered. The most important variable which affects the reactivity of sulphur dioxide in comminuted fillet steak, pork steak, pork chop, braising steak, shin beef and belly pork, is fat content, reactivity decreasing with increase in fat-content. This observation is explained in terms of liquid fat tending to smear, during comminution, over components of meat which are reactive towards the additive, thereby providing a protective barrier. In meat other than pork steak or chop, the reactive food components include disulphide bonds of proteins. The amount of S-sulphonate formed on addition of sulphur dioxide correlates with the cystine-content of the meat. The highest yield of S-sulphonate was obtained for shin beef where cleavage of disulphide bonds accounts for 48% of the additive which had undergone reaction. No S-sulphonate formation was observed for pork steak or pork chop samples.