Non-starter lactic acid bacteria

The contribution of these agents, individually or in various combinations, has been assessed in model cheese systems from which one or more of the agents was excluded or eliminated, e.g. by using an acidogen rather than starter for acidification or manufacturing cheese in a sterile environment to eliminate non-starter lactic acid bacteria (NSLAB). Such model systems have given very useful information on the biochemistry of ripening. 

Lipolysis. Some lipolysis occurs in all cheeses the resulting fatty acids contribute to cheese flavour. In most varieties, lipolysis is rather limited (Table 10.5) and is caused mainly by the limited lipolytic activity of the starter and non-starter lactic acid bacteria, perhaps with a contribution from indigenous milk lipase, especially in cheese made from raw milk. 

Blue cheeses undergo very extensive lipolysis during ripening up to 25% of all fatty acids may be released. The principal lipase in Blue cheese is that produced by Penicillium roqueforti, with minor contributions from indigenous milk lipase and the lipases of starter and non-starter lactic acid bacteria. The free fatty acids contribute directly to the flavour of Blue cheeses but, more importantly, they undergo partial /J-oxidation to alkan-2-ones (methyl O... 

Shakeel-Ur-Rehman, F., Bank, J. M., McSweeney, P. L. H., and Fox, P. F. (2000). Effect of ripening temperature on the growth and significance of non-starter lactic acid bacteria in Cheddar cheese made from raw or pasteurized milk. Int. Dairy J. 10,45-53. 

During cheese ripening, the population of starter bacteria generally decreases while the number of non-starter lactic acid bacteria (NSLAB) generally increases these changes are well documented for many full-fat rennet-curd cheese varieties, (e.g., Cheddar) (Cromie et al., 1987 Jordan and Cogan, 1993 McSweeney et al., 1993 Lane et al., 1997 Haque et al., 1997 Beresford and Williams, 2004). 

Jordan, K.N., Cogan, T.M. 1993. Identification and growth of non-starter lactic acid bacteria in Irish Cheddar cheese. Irish J. Agric. Food Res. 32, 47-55. 

Lane, C.N., Fox, P.F., Walsh, E.M, Folkersma, B., McSweeney, P.L.H. 1997. Effect of compositional and environmental factors on the growth of indigenous non-starter lactic acid bacteria in Cheddar cheese. Lait 77, 561-573. 

Williams, A. G., Noble, J., Tammam, J., Lloyd, D., Banks, J. M. (2002). Factors affecting the activity of enzymes involved in peptide and amino acid catahohsm in non-starter lactic acid bacteria isolated from Cheddar cheese. International Dairy Journal, 12, 841-852. 

Fitzsimons, N. A., Cogan, T. M., Condon, S., Beresford, T. (2001). Spatial and temporal distribution of non-starter lactic acid bacteria in Cheddar cheese. Journal of Applied Microbiology, 90, 600-608. 

Dozens of different peptides have been identified in cheeses. Most of them arise from and -caseins and a few are from aj2-and K-caseins. The proteinases involved in hydrolysis of aj -casein are mainly cathepsin D originating from milk and cell-envelope proteinase from thermophilic starters, while P- and aj2-caseins are mainly hydrolysed by plasmin. Moreover, peptidases from starters are also active throughout the ripening process, presumably similar to those from non-starter lactic acid bacteria. For example, the bitterness of mature Gouda cheese is caused by calcium and magnesium chlorides, some bitter-tasting free amino acids and is modified by peptides, which arise from the hydrolysis of fS-casein (such as decapeptide Tyr-Pro-Phe-Pro-Gly-Pro-Ile-His-Asn-Ser and derived nonanpeptide without the terminal serine) and casein (tetrapeptide Leu-Pro-Gln-Glu). 

De AngeUs, M., Calasso, M., Di Cagno, R., et al. (2010) NADP-glutamate dehydrogenase activity in non starter lactic acid bacteria effects of temperature, pH and NaQ on enzyme activity and expression. J Appl Microbiol 109, 1763-1774. 

Crow, V., Curry, B., and Hayes, M. (2001) The ecology of non-starter lactic acid bacteria (NSLAB) and their use as adjuncts in New Zealand Cheddar. Int Dairy J11, 275-283. 

Williams, A.G., Withers, S.E., and Banks, l.M. (2000) Energy sources of non-starter lactic acid bacteria isolated from Cheddar cheese. Int Dairy J10,17-23. 

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