ENHANCED BACTERIAL VIABILITY OF FREEZE-DRIED PROBIOTICS USING THE SUPERCOOLING PRETREATMENT

Freeze-drying is the state of the art in drying for the preparation of such susceptible probiotics with minimum losses in quality. However, the freezing process can lead to cell damages due to ice crystal formation, resulting in a reduction in the viability and physiological functionality of probiotics. In temperature drops from 37 to -80 degC with slow drop rates, there was a considerable loss of cell viability with average survival rates of 75% in commercial facilities. The addition of cryoprotectants could significantly reduce drying damage and improved storage stability. However, the protective mechanisms are complex and are not fully understood. In order to ensure the viability and uniform quality of freeze-dried probiotic products, special attention needs to be paid to supercooling as a pretreatment process. This project is aimed to develop a novel supercooling module to inhibit ice nucleation in conjunction with freeze-drying to enhance bacterial viability and shelf life of dried probiotics.Objective 1: Design and optimize a freezing unit integrated with the supercooling function for proof-of-conceptObjective 2: Test and validate the unit for enhanced viabilities of Lactobacillus acidophilus during freeze-drying and storageObjective 3: Characterize freeze-dried Lactobacillus acidophilus and test for bacterial survival following simulated in vitro digestion