Influence of glucose addition on the fermentation of soymilk with mixed yoghurt

Sojino mlijeko fermentirano je mješovitom jogurtnom kulturom uz bifidobakterije (Lactobacillus delbrueckii subsp. bulgaricus i Streptococcus thermophilus uz Bifidobacterium lactis Bb12). Fermentacija je provedena pri 42°C s (2% i 5%) i bez dodatka glukoze. Praćena je promjena kiselosti i promjena broja živih bakterijskih stanica tijekom fermentacije i čuvanja uzorka u hladnjaku pri temperaturi od 4 do 7°C tijekom 28 dana. Dodatak 2 ili 5% glukoze skratio je vrijeme fermentacije za oko 15 minuta, u odnosu na kontrolni uzorak (4 sata i 10 minuta), ali nije značajno utjecao na broj živih stanica pojedinih bakterijskih sojeva u fermentiranom sojinom mlijeku. Tijekom fermentacije najbolje su rasli streptokoki (oko 108 st/mL), a najslabije laktobacili (oko 106-107 st/mL). Dodatak glukoze nije utjecao na izgled i konzistenciju fermentiranog sojinog mlijeka. Tijekom 28 dana čuvanja proizvod je bio stabilan.Soymilk is fermented with mixed Yoghurt culture (Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus along with Bifidobacterium lactis Bb12).. Fermentation is performed at 42°C, with addition of glucose (2% and 5% ) and without glucose. 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 28 days. Addition of 2 or 5% glusose reduced fermentation time for about 15 minutes in comparison with control sample (4 hours and 10 minutes), but did not affect the number of viable cells in fermented soymilk. During the fermentation, Streptococcus thermophilus cultures have shown the best growth (about 108 CFU/mL), and Lactobacillus bulgaricus cultures have shown the minimum growth (about 106-107CFU/mL). Glucose addition did not significantly affect the appearance and consistency of fermented product. During the storage (28 days on 4-7°C) the fermented product was stable