A comparison of the survival rates of E. coli K12 and L. acidophilus in spray drying

The survival of mid-exponential and the early-stationary E. coli K12 and L. acidophilus were investigated when spray drying and outlet air temperatures of 60, 70, 80, 90 and 100°C. The results showed that the early-stationary cell of both cultures had a greater heat resistance than the mid-log cell in every drying temperature. The best survival rate was found when spray drying at temperature lower 80°C and it is showed that L. acidophilus is stronger than E. coli K12 (irrespective of the growth phase)

Formulation optimisation of mixed sugar/protein/maltodextrin encapsulants for spray drying L. acidophilus using the response surface method

Three sugars (maltose, fructose, and lactose) have been combined in different formulations with three protein based powders (whey protein, skim milk, and soy protein) to assess the survivability of L. acidophilus after spray drying at 80°C followed by optional further exposure to simulated gastric intestinal juice (SGI) or bile solution. The results showed that the highest survival rate was found in a recipe consisting of 87.5% skim milk and 12.5% maltose, while the lowest rates were found in formulations containing no protein. Maltose and lactose provide higher survival rate than fructose which may reflect the higher glass transition temperature of maltose/lactose mixtures. Similar trends were found with cells rehydrated in SGI and bile solutions