The technological usefulness of mesophilic lactic streptococci starters propagated in skimmed milk and in two different growth media at 24 and 30°C was evaluated. The effect of medium type and incubation temperatures on the number of lactic acid bacteria were studied including the percentage rate of the citrate-fermenting bacteria. The evaluation of the starters’ technological usefulness comprised two phases. There were compared contents of diacetyl and of CO2 in milk that was acidified to pH 5.2 using experimental starters. Starters that propagated at 24°C were used to produce Gouda cheese. After a 4 and 6 week ripening period, sensory properties of the cheese were evaluated. Owing to the growth media used, it was possible, especially when the incubation took place at 24°C, to obtain starters with higher numbers of lactic acid bacteria, and a higher percentage of citrate-fermenting bacteria; consequently, the aroma- and gas-forming activity of the starters was higher, too. Cheeses produced with starters, which propagated on the experimental media, had a more advantageous flavour and smell (a clearly nutty smell) and a significantly better eye structure than cheeses produced with a starter propagated on skimmed milk.
mesophilic starters, citrate-fermenting strains, diacetyl, CO2, sensory quality, Gouda cheese