Survival of Lactic Acid Bacteria during Spray Drying of Plain Yogurt

摘要

ABSTRACTSurvival ofStreptococcus salivariussubsp.thermophilusandLactobacillus debrueckiisubsp.bulgaricuswas determined under various processing conditions for spray drying. Numbers of both microorganisms decreased with increased outlet or inlet air temperature, and atomizing air pressure. Outlet air temperature was a major parameter affecting number of survivors. Suitable conditions were inlet air 160°C, outlet air 60°C, atomizing air pressure 98 kPa, hot air flow 0.28 m3/ min, and feed temperature 30°C. Spray‐dried yogurt powder showed lower survival forS. thermophilusand similar survival forL. bulgaricusas compared to freeze‐dried