A novel functional soy-based food fermented by lactic acid bacteria: Effect of heat treatment

Abstract

The development of a novel fermented soymilk product using selected lactic acid bacteria was performed. The immunomodulatory properties of strains able to grow in soymilk were evaluated in a murine model using inbred BALB/c mice. Lactobacillus acidophilus CRL 43 and CRL 1064 and Lactobacillus paracasei CRL 75 and CRL 208 were all able to significantly increase the phagocytic index (41 ± 4) compared with the control group (16 ± 3) when given individually. These strains were then used in the elaboration of multicultured fermented soymilks that were able to stimulate an innate immune response (peritoneal macrophage activation). However, these novel fermented products sometimes caused undesired secondary effects such as microbial translocation and animal weight loss. When the same fermented products were subjected to heat treatment, they were still able to stimulate the innate immune response without causing secondary effects. These results clearly show that it is not always necessary for lactic acid bacteria to be alive to exert a beneficial physiological effect. This study could thus be used as a model in the design and future evaluation of novel fermented vegetable products.