Fermentative activity of lactic acid bacteria in substrates based on soybean milk

Abstract

The fermentative activity of a mixed starter culture of Lb. acidophilus TMF6 and Bifidobacterium sp. TMF17a in soybean milk and supplemented soybean milk was examined. The supplementation of soybean milk was made with cows milk (10% v/v), beet root juice (5% v/v) and mixed (1:1 w/w of dry meter) beet root juice and yeast autolysate. The fermentative activity of these mixed culture was expressed as the number of viable cells (logCFU/mL), pH value, acidity (oT), and sugar content (glucose mg/L). The mixed starter cultures of Lb. acidophilus TMF6 and Bifidobacterium sp. TMF17a strains showed the best activity in soybean milk supplemented with mixed beet root juice and yeast autolysate, which has a significant effect especially on the number of viable cells of Lb. acidophilus TMF6.

Ispitivana je fermentativna aktivnost sojeva Lb. acidophilus TMF6 i Bifidobacterium sp. TMF 17a, kao združene kulture u sojinom mleku i u obogaćenom sojinom mleku. Obogaćivanje sojinog mleka vršeno je dodatkom soka cvekle (5% v/v), smeše (1:1 w/w suve materije) soka cvekle i autolizata pivskog kvasca (10% v/v) i kravljeg mleka (10% v/v). Fermentativna aktivnost je praćena u toku 8 sati na 42oC, određivanjem promene broja ćelija (logCFU/mL), pH vrednosti, ukupne kiselosti (oT, i promene sadržaja šećera izraženog kao glukoza (mg/L). Združena kultura sojeva Lb. acidophilus TMF6 i Bifidobacterium sp. TMF 17a je pokazala najbolju fermentativnu aktivnost u sojinom mleku sa dodatkom smeše soka cvekle i autolizata pivskog kvasca gde je uočena značajna stimulacija porasta broja ćelija soja Lb. acidophilus TMF6.