Effect of additives on the viability of bifidobacteria loaded in alginate poly-l-lysine microparticles during the freeze-drying process.
Bifidobacteria-loaded alginate poly-l-lysine microparticles (bap microparticles) were prepared using an air atomization method and then freeze-dried. The viability of the bap microparticles was investigated as a function of the amount of the bifidobacteria cultures, and the addition of a yeast extract, cryoprotectants, antioxidants and neutralizer. The size of the bap microparticles with and without the bifidobacteria was 84.8 +/- 28.5 microm (mean +/- standard deviation) and 113.1 +/- 38.5 microm, respectively. The surface morphology was slightly ellipsoid and wrinkled regardless of the incorporating bifidobacteria. The viability gradually decreased with increasing freeze-drying time. Free-flowing powdered bap microparticles were obtained at least 12 h after freeze-drying the wetted slurry of bap microparticles. However, the particles tended to aggregate when either lactose or ascorbic acid was added. The addition of a yeast extract, cryoprotectants (glycerol and lactose), antioxidants (NaHSO3 and ascorbic acid) and neutralizer (Mg3(PO4)2) resulted in a significantly higher viability of the bifidobacteria in the bap microparticles after freeze-drying (0.34-1.84 log) compared with the culture alone.
Cui
Jing-Hao
JH
National Research Laboratory for Bioavailability Control, College of Pharmacy, Kangwon National University, Chuncheon 200-701, Korea.
Cao
Qing-Ri
QR
Choi
Yun-Jaie
YJ
Lee
Kyung-Hoon
KH
Lee
Beom-Jin
BJ
D000464:Alginates; D000975:Antioxidants; D001431:Bacteriological Techniques; D001644:Bifidobacterium; D003451:Cryoprotective Agents; D005612:Freeze Drying; D050296:Microbial Viability; D010316:Particle Size; D011107:Polylysine / Q000031:analogs & derivatives*; D015003:Yeasts
D000464:Alginates; D000975:Antioxidants; D003451:Cryoprotective Agents; C051546:alginate-polylysine-alginate; D011107:Polylysine