Glutamate in meat processing – origin, function and novel application

Abstract

Glutamate is one of the most abundant amino acids in nature, accounting for up to 8-10% of most dietary proteins and peptides and most tissues. Only the free form of glutamate has taste-enhancing properties as a unique umami taste, and when glutamate is bound to proteins, it is tasteless with no umami taste. Fermentation, ageing, ripening and heat cooking are typical natural processes of protein hydrolysis during which free glutamate is released. The food industry most commonly uses it in the form of monosodium glutamate (MSG) in amounts between 0.1 and 0.8% as a flavour enhancer. Since the beginning of the 21st century, its use as a flavour enhancer in meat and meat products with reduced salt content has become more widespread. The sodium content of MSG (12.28 g/100 g) is one-third that of salt (39.34 g/100 g), making MSG a promising salt alternative in sodium reduction strategies. There is no one-sided and conclusive scientific information reporting adverse human health effects of MSG in the general population, and it is still considered safe. However, in the wake of "clean label" initiatives, many consumers would prefer not to have additives or flavour enhancers such as glutamates in their food. This can be overcome by the known synergistic effect of natural 5'-ribonucleotides and glutamates found in seaweed, cheese, fish sauce, yeast extract, soy sauce, fermented soybeans and tomatoes, as they enhance the overall perception of umami flavour.