Microbiological analyses
Preparation of decimal dilutions of VJs, Ins and KLBs was in Ringer's solution (Sigma–Aldrich, Milan, Italy). The cell suspensions were used to estimate the following microbial groups: total mesophilic count (TMC) on plate count agar (PCA), incubated aerobically at 30 °C for 72 h; Enterobacteriaceae on double-layered violet red bile glucose agar (VRBGA), incubated aerobically at 37 °C for 24 h; pseudomonads on Pseudomonas agar base (PAB) supplemented with 10 mg/mL cetrimide fucidin, incubated aerobically at 20 °C for 48 h; rod LAB on de Man-Rogosa-Sharpe (MRS) agar, acidified to pH 5.4 with lactic acid (5 mol/L) and incubated anaerobically at 30 °C for 48 h; coccus LAB on M17 agar, incubated anaerobically at 30 °C for 48 h; yeasts on dichloran rose Bengal chloramphenicol (DRBC) agar, incubated aerobically at 25 °C for 48 h. All media and supplements were purchased from Oxoid (Milan, Italy). Count plates were carried out in duplicate for each independent production.