HIGHLY ACTIVE FREEZE-DRIED PROBIOTIC CONCENTRATES WITH LONG SHELF LIFE

摘要

The application of probiotics in the composition of products intended to have long shelf life is limited due to their mandatory refrigeration storage. Increase in the resistance of probiotics to the production conditions and improvement of their viability throughout storage is achieved by microencapsulation. The preservation of probiotic strains for a long period of storage and low cost transportation and thus, resulting in ready-to-use cultures for dairy and other food-related industries including in the field of probiotics is facilitated by freeze-drying using appropriate cryoprotectant media. The used cryoprotectants are hydrocolloids which are natural, vegetable raw materials, with numerous beneficial physiological effects on the body. The aim of the present study is obtaining highly active probiotic freeze-dried bioproducts of selected probiotic strains by applying a combined modern biotechnology with the following main stages: selection, immobilization of the selected strains in the hydrocolloid matrix, cryoprotection, freezing and freeze drying. The selected probiotic strains Lactobacillus plantarum X2 and Lactobacillus paracasei RN5 are immobilized and freeze-dried using combined hydrocolloid matrix - sodium alginate and high-ester pectin. The survival of the two lyophilized microorganisms after lyophilization and in the course of storage for nine months is monitored – both strains retain high concentrations of active cells. The used hydrocolloids are appropriate for the mechanical immobilization of cellular cultures and as cryoprotectants. The new combined biotechnology allows the preparation of probiotic bioproducts with long shelf life and intact probiotic potential for application as supplements for foods with dietary purpose and in the prophylaxis and treatment of gastrointestinal disorders.