Technological variables influencing the growth and stability of a silage inoculant based on spray-dried lactic acid bacteria

Aims To investigate the influence of different culture media and fermentation conditions on growth performance and viability of three lactic acid bacteria (LAB) strains with potential as silage inoculants, and to optimize spray-drying in order to enhance survival to dehydration and storage stability. Methods and Results In house-formulated MRS was a suitable low-cost culture medium forLactobacillus plantarumHv75,Pediococcus acidilactici3903 andL. buchneriB463. Uncontrolled pH biomass production conferred enhanced stability during storage at 4 degrees C after spray-drying. The use of whey protein concentrate 35 (WPC)-maltodextrin (M) as matrix, inlet temperature of 145-150 degrees C and air flow rate of 601 l h(-1)was adequate for the production of dehydrated LAB. According to the desirability function, at this optimized condition, moisture content, yield and solubility were predicted to be 3 center dot 96, 73 center dot 68 and 90 center dot 36% respectively. Those conditions also showed a decrease of 0 center dot 855 log CFU per gram after drying, no loss in viability at 4 degrees C for 6 months and 1 log CFU per gram reduction at 25 degrees C. Conclusions Stable and economically feasible dehydrated LAB cultures were obtained using alternative culture media, fermentation under uncontrolled pH and optimizing spray-drying process conditions through the desirability function method. Significance and Impact of the Study Our results can be utilized for efficient production and commercialization of several dry LAB.