Influence of the temperature on the fermentation of soymilk by mixed ABT-5 culture

Sojino mlijeko fermentirano je mješovitom ABT-5 kulturom probiotičkih bakterija (Lactobacillus acidophilus, Bifidobacterium spp. i Streptococcus thermophilus). Fermentacija je provedena pri dvije različite temperature (37°C i 41°C). Praćena je promjena kiselosti i promjena broja živih bakterijskih stanica tijekom fermentacije, i nakon 24 sata čuvanja uzorka u hladnjaku pri temperaturi od 4 - 7°C. Kod bakterijskih vrsta Streptococcus thermophilus i Lactobacillus acidophilus primjećen je bolji rast stanica pri temperaturi od 37°C, dok je rast stanica bakterijske vrste Bifidobacterium spp. bio bolji pri 41°C. Pad pH-vrijednosti do izoelektrične točke sojinog proteina bio je neznatno brži pri 41°C i trajao je 1 sat kraće. Razlika u temperaturi fermentacije sojinog mlijeka nije značajno utjecala na izgled i konzistenciju fermentiranog sojinog mlijeka.Fermented soymilk was made with mixed ABT-5 culture of probiotic bacteria (Lactobacillus acidophilus, Bifidobacterium spp. and Streptococcus thermophilus). Fermentation was carried out at two different temperatures (37°C i 41°C). Changes of pH-values and number of viable cells were measured during fermentation and after storage of fermented soymilk in refrigerator at temperature of 4-7°C for 24 hours. Bacterial strains of Streptococcus thermophilus and Lactobacillus acidophilus survived better at 37°C, and Bifidobacterium spp. survived better at 41°C. Changes in pH-values were slightly faster at 41°C and fermentation of soymilk lasted 1 hour shorter. The difference in temperature didn't have a significant influence on the appearance and consistency of the fermented soymilk