Abstract
The effects of Lactobacillus rhamnosus (Lr), Lactobacillus casei (Lc), or Lactobacillus plantarum (Lp) in co-cultures with Streptococcus thermophilus (St) and Lactobacillus delbrueckii subsp. lactis (Ll) were examined on post-acidification, the viability of lactic acid bacteria, and antioxidant activity in yoghurt (Y) during 0, 7, 14, and 21 days of storage at 4 °C. Sensory evaluation of yoghurt was run on the first day of storage. Lr enhanced the viability of St in yoghurt. Lr, Lc, or Lp enhanced the viability of Lactobacillus spp. in yoghurt. Lc-Y and Lp-Y (0 day) exhibited higher (p < 0.05) radical scavenging activity than control yoghurt. FIC activity increased (p < 0.05) in both Lr–Y and Lc-Y at 14 days storage. Lc-Y and Lp-Y showed the highest FRAP values at 14 days storage. All three treatments showed low (p < 0.05) aroma scores. In conclusion, Lr, Lc, or Lp positively enhanced antioxidant activities in yoghurt.