Epsilon Archive for Student Projects

Abstract

The aim of this study was to develop a fermented, nutritional probiotic drink with the elderly population being the main target group, because of common health issues related to aging, such as gastrointestinal health and nutritional deficiencies. The probiotic drink was formulated with the addition of the probiotic bacterial strains Bifidobacterium longum subsp. longum BG-L47, Limosilactobacillus reuteri ATCC PTA 6475 and Lactococcus lactis 10399. These were co-cultivated in milk-based substrates with and without the addition of arabinoxylan-oligosaccharides (AXOS) as a prebiotic fibre. The strains were evaluated for their individual growth in co-cultivation, viability, ability to reduce pH, metabolite production, bile tolerance, and 5’nucleotidase activity, as well as the products’ sensory taste acceptability. The results from co-cultivations suggested synergistic interactions between B. longum BG-L47 and L. reuteri ATCC PTA 6475, where they showed an improved cell viability in milk-based media with AXOS supplementation. The pH decrease suggested an active fermentation and sensory tests highlighted the potential of this product as well as improvement areas in terms of flavour and acceptability. HPLC analysis showcased the production of short-chain fatty acids, where the content of lactate and acetate were particularly notable, contributing with functional benefits of the product. A risk assessment was performed to confirm microbial, physical and chemical safety during the production until storage stage of the product development. This risk assessment concluded the main concerns of this product is the potential contamination of Enterobacteriaceae, B. cereus and S. aureus during the production steps. These hazards were controlled with multiple heat treatments as well as acidic environments and cold storage, and hygienic handling of the product. Prior to the sensory analysis a contamination analysis for Enterobacteriaceae was performed and no contamination was observed. Overall, this study suggests that the product formulation that is proposed in this report could be a promising foundation for a future fermented, nutritional probiotic drink contributing to improved health in the elderly population.