Vestnik MGTU (Sep 2019)
Viability of the culture of Bifidobacterium bifidum immobilized by microencapsulation in dairy drink and the simulated gastrointestinal liquids
Abstract
The existing technologies of the enriched dairy drinks assume enrichment of a product by live microorganisms, so-called probiotics, generally lactobacilli and bifidobacteria. However, the viability of probiotics and quality of many products enriched with probiotics still represent a serious problem as the quantity of viable probiotics and especially bifidobacteria decreases in dairy products in storage time and subsequently during gastrointestinal transit over time. To protect pro-biotic cultures during processing, storage in foodstuff and gastrointestinal transit, innovative technologies, such as microencapsulation have been investigated. The aim of the research is to study the effect of the immobilization of Bifidobacterium bifidum in the structure of alginate microcapsules on the strain viability during storage in a fermented milk drink and the effects of simulated gastrointestinal fluids on it. Objects of researching are the strain of Bifidobacterium bifidum 791 immobilized by microencapsulation in the alginate matrix and microcapsules consisting of the natural biodegraded natural polymers. Influence of the alginate matrix on morphological features of Bifidobacterium bifidum 791 as a result of microencapsulation has been investigated. In micromedicine the foreign currency changed forms are not noted that demonstrates lack of negative impact of structure of the microcapsule on bifidobacteria. Considerable decrease in quantity of viable bifidobacteria in the model environment of a stomach (pH 1.2) to 62.2 % in the sample which is not protected by the microcapsule has been found. In the immobilized Bifidobacterium bifidum 791 sample decreasing in concentration of viable bifidobacteria has happened in structure of alginate hydrogel for37.5 % of initial concentration when passing the model environment of stomach (рН 1.2). The received microcapsules have the closed surface and average diameter of 150 microns. Concentration of bifidobacteria cages in the yogurt containing the encapsulated probiotics does not decrease below the recommended level (106–107 colony forming units per gram) within 14 days of storage. Dairy drink has met the requirements of Technical regulations of the Customs union "About safety of milk and dairy products" for physical and chemical indicators.
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