Production of fermented probiotic beverages

U sklopu probiotičkog koncepta, u prethodnim istraživanjima, definirana su probiotička svojstva tri soja bakterija mliječne kiseline: Lactobacillus acidophilus M92, Lactobacillus plantarum L4 i Enterococcus faecium L3. U ovom radu istražena je mogućnost primjene ovih probiotičkih sojeva te bakterijskog soja Lactobacillus rhamnosus GG za proizvodnju probiotičkog napitka od permeata mlijeka, obogaćenog s 10% retentata sirutke. Tijekom kontrolirane fermentacije, probiotički sojevi su proizveli cca 3,5 g/l mliječne kiseline, pH vrijednost je iznosila oko 4,7, a broj živih stanica je ostao visok (~107 CFU/ml). Visok broj živih stanica primjenjenih probiotičkih sojeva održao se tijekom 4 tjedna čuvanja pri temperaturi od 4°C. Primjenjene starter kulture preživjele su proces liofilizacije u visokom broju (cca 108 CFU/ml). Broj živih stanica liofiliziranih bakterijskih kultura ostao je nepromijenjen tijekom šest mjeseci čuvanja. Nadalje, bakterijske kulture, izolirane tijekom spontane fermentacije permeata mlijeka, obogaćenog s 10% retentata sirutke, ispitane su kao autohtoni sojevi bakterija mliječne kiseline za primjenu u proizvodnji fermentiranog napitka. SDS-PAGE eletroforeza 5 bakterijskih izolata pokazala je da se radi o 3 različita soja bakterije, a jedan od njih je identificiran kao Lactobacillus plantarum. Svi bakterijski izolati su pokazali antibakterijsko djelovanje prema šest različitih test mikroorganizama što je jedno od važnih svojstava potencijalnih starter kultura.In previous researches, in the context of probiotic concept, three strains of lactic acid bacteria with probiotic properties have been defined: Lactobacillus acidophilus M92, Lactobacillus plantarum L4, and Enterococcus faecium L3. Research was undertaken to determine the suitability of milk permeate (with 10 % whey retentate) as a raw material for production of fermented probiotic beverage by lactic acid bacteria (Lactobacillus acidophilus M92, Lactobacillus plantarum L4, Enterococcus faecium L3 and Lactobacillus rhamnosus GG). During this controlled fermentation, probiotic strains have produced 3.5 g/L lactic acid, pH was around 4.7, and number of live cells stayed high (~107 CFU/ml). Number of viable count of probiotic bacteria maintained high during 4 weeks of the preservation at 4°C. Choosen starter cultures survived successfully the freeze-drying process (~108 CFU/ml). The number of live cells stayed immutable during six months of preservation. Furthermore, characterisation of lactic acid bacteria isolated from spontaneous fermantation of milk permeate (with 10 % whey retentate) was additionally carried out as a possible starter cultures consisting of autochtonous lactic acid bacteria for the production of fermented beverage. Phenotypic characterisation of 5 isolated strains was done by SDS-PAGE of whole cell proteins. Electrophoretic pattern revealed 3 different bacterial strains and one of them was identified as Lactobacillus plantarum. All of this strains have showed antibacterial activity against 6 different test microorganisms which is one of the desirable properties of potential starter cultures