The influence of different supplements on the probiotic character of fermented whey-based beverage

Abstract

The aim of this study was the selection of appropriate supplements for the probiotic whey-based beverage production by Lactobacillus johnsonii NRRL B-2178. The analysis of the main effects and their interactions was performed by using a fractional factorial experimental design through a small number of experiments. After 8h of fermentation of the reconstituted whey, enriched by investigated supplements, a cell number achieved in the probiotic whey-based beverage was determined. By using a statistical analysis, the amount of supplements which are necessary to obtain the maximal number of viable cells in the beverage was also determined. Based on the obtained results, among all nitrogen sources the yeast extract in the concentration of 1,5 % achieves the most significant influence on the Lactobacillus johnsonii NRRL B-2178 growth. As the sources of vitamins and minerals, piridoxal and ZnSO4 has the most significant influence on the number of cells at concentrations of 0,001 % and 0,3 %, respectively. By examining the three groups supplements, the largest number of cells approximately 8,80 log(CFU/mL) can be obtained by using the maximum amount of the yeast extract.

U ovom radu ispitan je uticaj različitih izvora azota, vitamina i minerala na rast soja Lactobacillus johnsonii NRRL B-2178 u cilju postizanja maksimalnog broja živih ćelija pri proizvodnji probiotskog napitka na bazi surutke. Analiza uticaja pojedinačnih i združenih efekata ispitivanih dodataka vršena je primenom frakcionalnog faktorskog dizajna eksperimenata uz izvođenje minimalnog broja eksperimenata. Nakon 8 h fermentacije surutke obogaćene ispitivanim dodacima određivan je broj živih ćelija (kao odgovor sistema) u probiotskom napitku. Statističkom obradom podataka ujedno je procenjena i količina dodataka koja je neophodna za postizanje maksimalnog broja živih ćelija u napitku. Na osnovu dobijenih rezultata, iz grupe ispitanih izvora azota najveći uticaj na rast soja Lactobacillus johnsonii NRRL B-2178 ostvaruje ekstrakt kvasca pri koncentraciji od 1,5 % (w/v). Kao izvori vitamina i minerala najveći uticaj na rast ćelija ispoljavaju vitamin B6 i ZnSO4 u koncentracijama 0,001 % i 0,3 %, respektivno. Pri ispitivanju sve tri grupe dodataka najveći broj ćelija (oko 8,80 log CFU/mL) se može ostvariti primenom maksimalne količine ekstrakta kvasca.