The Role of Lactic Acid Bacteria in Safety and Flavour Development of Meat and Meat Products

Abstract

Lactic acid bacteria (LAB) are widespread in nature and commonly occur on all kind of plant materials, on mucous membranes, in saliva and, in feces. Consequently and unavoidably they are part of the contamination flora of fresh meats after slaughter. Under certain conditions, e.g. in packaged refrigerated meats or raw sausage meats, they are able to compete efficiently with accompanying microorganisms for nutrients and may reach substantial viable counts. Their metabolic activities may ultimately result in either a desired preservative effect due to the repression of pathogenic and spoilage microorganisms, a desired tasty meat product, such as raw fermented sausage, or in meat spoilage through undesired transformations of raw and cooked meats. Heterofermentative LAB of the Carnobacterium, Leuconostoc and Weissella genera are usually more involved in meat spoilage than the homofermentative Lactobacillus and Pediococcus genera. Therefore, commercially available meat starter cultures for dry-fermented sausage production exclusively belong to the latter two. Homofermentative LAB produce almost exclusively lactic acid from fermentable carbohydrates present in meats, which is relatively mild and palatable, while heterofermentative species produce significant amounts of less desirable fermentation end products, such as CO2 gas, ethanol, acetic acid, butanoic acid and acetoin. However, under certain conditions Lactobacillus spp. may also produce significant amounts of acetic acid, ropy slime and, discolouration (greening) of meats [1,2].