evaluation of the effect of spirulina platensis on the viability of lactobacillus acidophilus (la-5) in yogurt and its properties

Dairy products are known as the best carriers of probiotics and prebiotics, among which yogurt has a special place due to its ability to preserve probiotics. the aim of this study was to evaluate the prebiotic effect of spirulina platensis extract (spe) at a rate of 0.5 and 1.5% on the viability of probiotic bacteria lactobacillus acidophilus (cfu/ml 1 × 108) in yogurt during storage at refrigerator (4 ± 1°c). samples were designed in four groups including control, probiotic, probiotic + 0.5% spe and probiotic + 1.5% spe. then, the viability of probiotic, chemical (titratable acidity and ph) and sensory tests were done. the findings showed that the highest growth of probiotic bacteria was related to the treatment containing 1.5% spe (5.68 log cfu/g), which compared to 0-day and the end of the study. this treatment had a lower decrease than the probiotic treatment and the control. also, it was found that the viability rate of probiotic bacteria increases in the presence of spe. in addition, during the study, titratable acidity and ph increased and decreased, respectively (p < 0.05). according to the findings of the present study, it was found that the addition of spe improves the viability of l. acidophilus, which indicates the desirability of using this combination to increase the viability of probiotic bacteria in probiotic products.