Evaluation of physicochemical properties and lactic acid bacteria survival in watercress extract (Nasturtium officinale) functional beverage

In this research, Lactobacillus casei and Lactobacillus acidophilus bacteria were added to watercress drink and the physicochemical properties, antioxidant activity, viability of probiotic bacteria and sensory characteristics of the samples were investigated in the period of 1, 15 and 30 days after production. The results showed that the pH in all samples decreased significantly with time. Brix of the samples containing higher amounts of watercress was more, and with the passage of time, the turbidity of all samples decreased significantly. The samples containing higher amounts of watercress had higher total phenol and antioxidant activity, and with the passage of time, the IC50 of all samples increased significantly and their total phenol decreased significantly. On the 1st and 15th days, the highest viability rates of both microorganisms belonged to samples containing 75% watercress. Watercress extract helped the viability of Lactobacillus casei and Lactobacillus acidophilus with its antioxidant activity and significant phenolic compounds. The results of the sensory evaluation showed that there was no statistically significant difference in the score of flavor, aroma, texture, color and overall acceptability of the samples on all the days investigated.