Potential of protein-prebiotic as protective matrices on the storage stability of vacuum-dried probiotic Lactobacillus casei

The impact of protein-prebiotic protective system was evaluated for their capability on probiotic Lactobacillus casei TISTR 1463 during vacuum drying and subsequent storage. Plant protein mixed with sorbitol (PS) possessed the greatest storage stability associated with the lowest inactivation rate (k) verified by non-linear inactivation model after storage at 4 degrees C for 180 days and 30 degrees C for 90 days. The physical property of protective matrices in term of glass transition temperature (T-g) was also determined. Vacuum-dried probiotic containing PS exhibited the greatest Tg values of 38.7 and 68.3 degrees C at the storage temperature of 4 and 30 degrees C, respectively. It could be indicated that a great difference in T-T-g related to the increase of storage stability. Vacuum drying process affected the functional properties of probiotic including cell surface hydrophobicity, antimicrobial activity and the tolerance to gastrointestinal tract conditions. The supplementation of protective agents was potentially effective in remaining high level of probiotic properties.