MODELLING THE KINETICS OF FUNCTIONAL STARTER CULTURES TO IMPROVE FOOD FERMENTATION PROCESSES
Functional starter cultures of lactic acid bacteria are defined as strains that are used as starter cultures for food fermentation, and that are able to express certain functional properties which give an added value to the end-product (e.g. bacteriocin producers, exopolysaccharide producers, probiotic strains). A key problem is that in some cases strains that display promising behaviour under optimal laboratory conditions do not express their functional properties in an actual food environment. Predictive modelling techniques, which are usually applied to estimate the outgrowth, inactivation or toxin production of food spoilers and pathogens, may be successfully applied to investigate the application potential of functional starter cultures, and to unravel the mutual influences between a food environment and bacterial functionality. As a case study, the biokinetic features of several functional lactic acid bacteria (Lactobacillus sakei CTC 494, Lactobacillus curvatus LTH 1174, Lactobacillus amylovorus DCE 471, Enterococcus faecium RZS C5, and Streptococcus thermophilus LY03) were studied through primary, secondary, and tertiary modelling as a function of environmental characteristics which are typical for certain fermented foods (e.g. yoghurt, fermented sausage and sourdough). Several conclusions could be drawn with respect to starter selection and fermentation technology. For instance, the meat isolates Lb. sakei CTC 494 and Lb. curvatus LTH 1174 turned out to be promising novel bacteriocin-producing starters for sausage fermentation, whereas Lb. amylovorus DCE 471 seemed more suitable as a starter for industrial sourdough fermentation. E. faecium RZS C5 has potential to be used as a bacteriocin-producing coculture for food fermentations. Moreover, modelling indicated how exopolysaccharide production by S. thermophilus LY03 in yoghurt may be optimised by adjusting the process conditions.
Leroy, F., Verluyten, J., Neysens, P., Degeest, B., Messens, W. and De Vuyst, L. (2001). MODELLING THE KINETICS OF FUNCTIONAL STARTER CULTURES TO IMPROVE FOOD FERMENTATION PROCESSES. Acta Hortic. 566, 363-368
lactic acid bacteria, Listeria, sausage, sourdough, yoghurt, bacteriocins, exopolysaccharides