title: Effect of starch- and lipid-based encapsulation on the culturability of two Bifidobacterium longum strains.
abstract: OBJECTIVE
  To assess the applicability of starch- and lipid-based encapsulation methods for improving the viability and culturability of two Bifidobacterium longum strains stored in fermented and nonfermented foods.
  
  
  RESULTS
  Cells were encapsulated with partially hydrolysed potato starch granules combined with amylose coating, or entrapped in cocoa butter matrix. The tested B. longum strains were not adherent to the starch granules, and the culturability of the cells stored in fermented and nonfermented foods was not improved by starch-based encapsulation. Encapsulation of the cells in cocoa butter was found to increase the plate counts during storage. In addition to plate counts, viability of the cells was measured by fluorescent microscopy using LIVE/DEAD BacLight viability assay. Microscopic counts of the viable cells did not change significantly during storage, suggesting that the cells remained alive despite becoming unable to grow on nutrient agar plates.
  
  
  CONCLUSIONS
  Encapsulation with cocoa butter increased the culturability of the cells, but encapsulation with hydrolysed potato starch had no effect. Culture-independent viability assay suggested that cells remained viable despite being unable to grow on agar plates.
  
  
  CONCLUSIONS
  This study indicates that encapsulation techniques may be useful in improving the culturability of bacteria, but the plate counts may yield insufficient data on the actual viability of the cells.
authors: Department of Biochemistry and Food Chemistry, Functional Foods Forum, University of Turku, Turku, Finland. sajola@utu.fi
authors: S J
authors: SJ
authors: Lahtinen
authors: A C
authors: AC
authors: Ouwehand
authors: S J
authors: SJ
authors: Salminen
authors: P
authors: P
authors: Forssell
authors: P
authors: P
authors: Myllärinen
mesh_terms: D001422:Bacterial Adhesion; D001644:Bifidobacterium / Q000254:growth & development* / Q000502:physiology; D002214:Capsules; D004041:Dietary Fats; D005516:Food Microbiology; D005519:Food Preservation; D019936:Probiotics; D011198:Solanum tuberosum / Q000737:chemistry; D013213:Starch
chemical_list: D002214:Capsules; D004041:Dietary Fats; C052387:cocoa butter; D013213:Starch