Effect of steviol glycosides as sugar substitute on the probiotic fermentation in milk gels enriched with red beetroot (Beta vulgaris L.) bioactive compounds

Abstract

In this study, the effects of steviol glycosides as sugar substitute on the probiotic fermentation and gelation properties of milk gels enriched with red beetroot (Beta vulgaris L.) bioactive compounds and natural colourants were studied. As a result, the viability of Lactobacillus acidophilus was maintained within probiotic and therapeutic levels (>9 log cfu mL(-1)), due to the possible prebiotic effect of stevia and biologically metabolized compounds of red beetroot, during storage of the probiotic milk gels. In conclusion, fermented gels with total phenolics, anthocyanins, total antioxidant capacity (DPPH and FRAP) of red beetroot bioactive components and sweetened with steviol glycosides showed a significant increase in bacterial growth of L. acidophilus and acceptable sensory and colour (L*, a*, b*, Delta E*, C*, h*) characteristics with enhanched textural gel matrix. Therefore, fermented milks with stevia as an alternative non-caloric sweetener and naturally coloured red beetroot may be an alternative for therapeutic dairy product having positive synergistic interactions providing a rich deliver probiotic bacteria.