Analysis of some physicochemical, rheological, sensorial properties, and probiotic viability of fermented milks containing Enterococcus faecium and Enterococcus durans strains

Abstract

The aim of this research was to observe the combined usability of Enterococcus faecium and Enterococcus durans strains, which are resistant to adverse environmental conditions, together with commercial probiotic starters in the production of probiotic fermented milk. Accordingly, eight different probiotic fermented milks were produced; AF:Lactobacillus acidophilus + Enterococcus faecium, BF:Bifidobacterium animalis subsp. lactis + Enterococcus faecium, CF:Lactobacillus casei + Enterococcus faecium, RF:Lactobacillus rhamnosus + Enterococcus faecium, AD:Lactobacillus acidophilus + Enterococcus durans, BD:Bifidobacterium animalis subsp. lactis + Enterococcus durans, CD:Lactobacillus casei + Enterococcus durans, RD:Lactobacillus rhamnosus + Enterococcus durans. As a result of the data obtained in the study, it was found that fermented dairy products containing Enterococcus faecium and Enterococcus durans had no negative effects on the physicochemical, rheological properties and probiotic viability, and positively affected the sensory properties of the samples. The viscosity and hardness values of probiotic fermented milk produced by combining with E. durans were higher than by combining with E. faecium and serum separation was not occurred. Also, probiotic bacteria viability was higher than 7 log cfu/ml level at the end of the storage period. Practical applications Enterococci are found naturally in the human intestinal microbiota and are highly resistant to adverse environmental conditions. Enterococcus strains that produce antimicrobial peptides such as enterocin were found to be able to effectively inhibit the development of many food pathogens when they are added to some foods including cheese. They are microbial additives that are thought to be used in many foods to improve food safety. The bacteriocin called enterocin could act as natural bio-preservatives in foods. This study will guide the use of Enterococcus species as bio-preservative in foods such as dairy products and the possibility of the continuation of probiotic viability.