Viability of probiotics and antioxidant activity of soy and almond milk fermented with selected strains of probiotic Lactobacillus spp.

This research focused on the impact of four strains of probiotic Lactobacillus spp. i.e. L. rhamnosus (Lr), L. aci-dophilus (La), L. plantarum (Lp), or L. casei (Lc) individually on post-acidification, the viable cell counts (VCC), total phenolic and flavonoid contents (TPC and TFC, respectively), and antioxidant activity of fermented (F) plant-based milk drink made from individual soy (S) and almond (A) milk (M; 100:0 v/v) and their combination (75:25, 50:50, & 25:75; v/v) during 0, 7, 14, & 21 days of storage. All samples showed VCC of 6 log cfu/ml compared to their respective controls (without bacteria; 3-4 log cfu/ml; p < 0.05). TPC significantly increased in the first week for FSM/AM (75:25)-Lr and in the last two weeks for FAM (100)-& FSM/AM (50:50)-Lr. FAM (100)-& FSM/AM (50:50)-Lr exhibited the highest TFC among other samples during storage. La, Lp, or Lc in FSM & FAM (100) increased the radical scavenging activity and FIC ability to about 95% in the last two weeks of storage. Lr in FSM & FAM (100) and FSM/FAM (75:25 & 25:75) enhanced FRAB activity during storage. In conclusion, fermented soy and almond milk and their combination could serve as an effective vehicle for pro-biotics with antioxidant activity.

Automated summary

This study investigated the effects of four strains of probiotic Lactobacillus spp. on post-acidification, viable cell counts, total phenolic and flavonoid contents, and antioxidant activity of fermented plant-based milk drinks made from soy and almond milk. The results showed that fermented soy and almond milk and their combination can serve as an effective vehicle for probiotics with antioxidant activity.