| Abstract [eng] |
Probiotic bacteria are used in the production of functional foods, pharmaceuticals and cosmetics. They play an important role in maintaining good human health. To ensure health benefits, probiotics should remain viable during storage and/or in the gastrointestinal tract. Most studies have shown that the non-encapsulated or immobilized probiotic bacteria have low viability in products. Therefore, the task of the study was to produce stable multiple emulsions V1/A/V2 with probiotic and prebiotic in phase V1, with plant extract in phase A and sodium alginate in phase V2. Then obtain polysaccharide capsules from the stable emulsions by meshing them in calcium chloride solution. Also, the release of probiotics from capsules and multiple emulsions in simulated digestive conditions in vitro was also evaluated. During the research work, the influence of three different emulsifiers (Tween 80, Span 80, Lecithin) and their concentrations on single-layer water-in-oil (V/A), oil-in-water (A/V) emulsions and multiple water-in-oil-in-water (V1/A/V2) emulsions stability. The stability of the emulsions is evaluated by the separation of the phases forming it in static (storage) conditions. Stable A/V emulsions were found to be formed using 0,5 % Tween 80, 0,5 % Tween 80 + lecithin, 2 % lecithin or 5 % Span 80 emulsifiers at 6:4 oil/water ratio. However, in the oil-to-water ratio, 7:3 stable emulsions were obtained only with 0,5 % Tween 80, 0,5 % Tween 80 + Span 80 and 10 % Span 80 emulsifiers. The stability of V/A emulsions has been shown to be stable only with 5 % and 10 % Tween 80 + lecithin emulsions to form a water-to-oil ratio of 6:4, and water-to-oil ratio of 7:3 produces no stable emulsions. At the next stage of the study, multiple emulsions were produced from the resulting stable V/A (5 % and 10 % Tween 80 + lecithin) emulsions. Different concentrations of sodium alginate (1 % and 2 %) in the V2 phase differed between the produced emulsions. The stability of multiple emulsion V1/A/V2 was found to result in stable multiple emulsions with 2 % alginate additive in the outer phase V2. Therefore, they were encapsulated with probiotic bacteria along with prebiotics and plant extract. Prior to that, the viability of probiotic bacteria was assessed after 48 hours with four different prebiotics (inulin, trehalose, mannitol, glucomannan) to determine which prebiotic to choose for encapsulation. Bacteria have been found to be best suited for mannitol and trehalose. Further studies assessed the viability of probiotics in simulated in vitro digestive conditions by uncontrolled (control) and encapsulated Lactobacillus plantarum bacteria at different digestive stages. It has been found that after the simulated in vitro digestion, bacteria survive better when they are encapsulated. Then they can be delivered to the target site, that is, the human intestine. |
