Response surface optimization of lyoprotectant for Lactobacillus bulgaricus during vacuum freeze-drying.
The individual and interactive effects of skimmed milk powder, lactose, and sodium ascorbate on the number of viable cells and freeze-drying survival for vacuum freeze-dried powder formulation of Lactobacillus bulgaricus were studied by response surface methodology, and the optimal compound lyoprotectant formulations were gained. It is shown that skim milk powder, lactose, and sodium ascorbate had a significant impact on variables and survival of cultures after freeze-drying. Also, their protective abilities could be enhanced significantly when using them as a mixture of 28% w/v skim milk, 24% w/v lactose, and 4.8% w/v sodium ascorbate. The optimal freeze-drying survival rate and the number of viable cells of Lactobacillus bulgaricus were observed to be (64.41±0.02)% and (3.22±0.02)×10(11) colony-forming units (CFU)/g using the optimal compound protectants, which were very close to the expected values 64.47% and 3.28×10(11) CFU/g.
a College of Life Science & Engineering , Shaanxi University of Science & Technology , Xi'an , China.
He
H
Chen
Shiwei
S
Chen
Chuanna
C
Li
Guowei
G
Shu
D000818:Animals; D001205:Ascorbic Acid; D015169:Colony Count, Microbial; D003451:Cryoprotective Agents / Q000494:pharmacology*; D005612:Freeze Drying / Q000379:methods*; D007778:Lactobacillus / Q000737:chemistry* / Q000187:drug effects; D007785:Lactose; D008892:Milk; D012044:Regression Analysis; D014618:Vacuum
D003451:Cryoprotective Agents; D007785:Lactose; D001205:Ascorbic Acid
Lactobacillus bulgaricus; freeze-drying; lyoprotectant; survival rate