Effect of packaging conditions and temperature on viability of microencapsulated bifidobacteria during storage

In this study, Bifidobacterium longum B6 and B infantis CCRC 14633 were microencapsulated in various wall materials, including skim milk, gum arabic, gelatin and soluble starch. The stability of these microencapsulated bifidobacteria held at 25 or 4 °C in glass or polyester bottles with or without deoxidant and desiccant was determined. Microencapsulated cells of B longum B6 were generally more stable than the corresponding microencapsulated cells of B infantis CCRC 14633 under the various storage conditions tested. The presence of deoxidant and desiccant, especially at 25 °C, increased the survival of microencapsulated cells. Furthermore, the survival of bifidobacteria was enhanced when they were stored at 4 °C in glass bottles. It was also found that the wall material affected the survival of microencapsulated bifidobacteria. The viability of B longum B6 and B infantis CCRC 14633 was best when they were encapsulated in skim milk and held at 4 °C in glass bottles. Skim milk-encapsulated B longum B6 cells showed a relatively low viability reduction of only 0.15-0.20 log (colony-forming units (cfu g^-1)) after 42 days of storage at 4 °C in glass bottles, regardless of the presence of deoxidant and desiccant. A reduction of 0.38-0.76 log (cfu g^-1) was noted for skim milk-encapsulated cells of B infantis CCRC 14633 under similar storage conditions.