Effectiveness assessment of the bifidobacteria encapsulation when enriching juice-containing beverages with probiotics

Beverages are among the most popular types of products that attract attention of researchers for enrichment with functional ingredients. The introduction of probiotics into the food matrix can increase the usefulness of food products, including beverages. However, probiotics are extremely sensitive to extreme environmental conditions, which significantly limits their ability to survive in food. The aim of the research is to establish an effect of encapsulation on the preservation of bifidobacteria in an enriched juice-containing beverage. Capsules from sodium alginate were used to protect probiotic microorganisms (bifidobacteria of six strains in the symbiotic starter) from unfavorable conditions of the environment of the food system and the gastrointestinal tract. The capsules were obtained by the drip method. The stability of the capsules was determined under different conditions. Their solubility in water and at pH values typical for the stomach (1.1–1.6), small intestine (7.8–8.2), and large intestine (8.0–8.5) were studied. The tests were carried out upon keeping in buffer solutions for 15 and 30 min. In addition, the stability of the capsules in apple juice with a pH of 3.82 when stored at 4±1°C for 7, 14, 21, and 28 days was assessed. Capsule losses during heat treatment were analyzed. The amount of bifidobacteria extracted from the capsules after mechanical destruction with their subsequent inoculation on the GMK1 medium was also monitored during juice storage. The results of the studies showed that the greatest destructive effect was observed in an acidic environment typical for the stomach, where losses amounted to 47.4% after 30 min. Capsule losses at pH values typical for different parts of the intestine ranged from 25.3 to 30.9%. The selected food system, apple juice, turned out to be a less aggressive environment for the capsules, in which the destruction of capsules was 8.7% after 28 days of storage. Capsule losses under the selected juice pasteurization modes ranged from 60.17% during processing for 10 minutes at 85°C to 67.42% during juice processing for 30 minutes at 98°C. The differences were statistically significant (p≤0.05). Thus, using the obtained data, it is possible to predict the total loss of capsules and probiotic microorganisms during the digestion and storage of the product and inoculate the required amount to impart probiotic properties to the product. The research has development prospects taking into account the possibility of varying the taste and aroma properties of both the food system and the capsules.