Characterisation of lactic acid bacteria and yeast strains isolated from traditional yoghurts to obtain new starter culture combinations and the properties of products during the storage period

Abstract This study aimed to create new starter culture combinations by isolating lactic acid bacteria and yeast strains from traditional yoghurts. Accordingly, 80 strains were isolated from 23 samples. The strains developed acidity within 16 hr, with a pH range of 4.13–5.98. Subsequently, 26 of these strains produced exopolysaccharide (EPS, 0.0–3.3 mg/L) and 5 showed proteolytic activity. The 10 superior strains were identified as Lactiplantibacillus plantarum, Lactobacillus rhamnosus, Enterococcus faecium, Enterococcus sp., and Candida kefyr. Four groups of yoghurts were produced with three starter culture combinations and a control. During the 21-day storage, all groups exhibited similarities in physicochemical properties and protein profiles (via SDS-PAGE). However, the volatile component content varied depending on the starter culture combination and storage period. Sensory analysis showed that the experimental yoghurts were preferred over the control group. These findings suggest that the starter culture combinations could be effectively used in industrial yoghurt production.