Influence of L-cysteine, oxygen and relative humidity upon survival throughout storage of probiotic bacteria in whey protein-based microcapsules

摘要

The survival rates of Lactobacilus acidophilus Ki, Lactobacillus paracasei L26 and Bifidobacterium animalisBB-12 were studied after whey protein microencapsulation via spray-drying, with or without L-cysteine-HCl, and storage up to 6 months at 5 C and 22 C, with variation in relative air humidity and oxygenlevels. Lb. paracasei L26 was the least susceptible to storage conditions: above 106 cfu g 1 were recordedby 180 d at 22 C, irrespective of relative humidity, and the presence/absence of oxygen and L-cysteine.Higher relative humidity, higher temperature and longer storage periods were deleterious to survival ofboth B. animalis BB-12 and Lb. acidophilus Ki; the effect of L-cysteine-HCl was dependent on the probioticstrain. The effect of overhead oxygen was not significant upon any probiotic strain studied. Whey proteinmicrocapsules containing L-cysteine-HCl protected probiotic cultures from simulated gastrointestinalconditions.