Application of wild starter cultures for flavour development in pilot plant cheese making

A number of wild lactococci of dairy and non-dairy origin which have the ab ility to produce unusual new flavours in model systems were studied with re gard to various characteristics important for cheese making. Ail strains we re found to be non-lysogenic and resistant to phages affecting strains pres ent in commercial starters. Since the overall acidifying activity of many p otentially interesting strains is rather low, they were used in combination with commercial starters. Defined-strain starter cultures (DSS) were prepa red, composed of a combination of wild strains together with industrial str ains, and tested in real cheese making (Gouda-type) experiments. The popula tion dynamics of DSS were studied to understand the behaviour of the select ed wild strains in the cheese environment. Wild strains showed various inte ractions with industrial strains in a defined-strain starter culture. Some wild strains, which were able to grow well together with industrial strains could be used relatively easily for practical applications. Other strains appeared to inhibit the growth of the industrial strains, due to the produc tion of bacteriocins. In many cases the bacteriocin appeared to be nisin. S ensory evaluation revealed that the selected wild strains also produced typ ical flavours in a real cheese environment which corroborated the results o btained in model systems. GC/MS data confirmed the results of sensory evalu ations. (C) 2000 Elsevier Science Ltd. All rights reserved.