Protective effect of soy powder and microencapsulation on freeze-dried Lactobacillus brevis WK12 and Lactococcus lactis WK11 during storage

• Published in: Food science and biotechnology Vol. 24; no. 6; pp. 2155 - 2160
• Main Authors: Gwak, Hyun Jung, Lee, Jong-Hee, Kim, Tae-Woon, Choi, Hak-Jong, Jang, Ja-Young, Lee, Sang Il, Park, Hae Woong
• Format: Journal Article
• Language: English
• Published: Seoul The Korean Society of Food Science and Technology 01.12.2015; 한국식품과학회
• Subjects: calcium alginate; Chemistry; Chemistry and Materials Science; cryoprotectants; Food Science; freeze drying; lactic acid bacteria; Lactobacillus brevis; Lactococcus lactis; microencapsulation; Nutrition; protective effect; Research Note; skim milk; synergism; temperature; trehalose; viability; yeast extract; 식품과학; encapsulation; freeze-drying process; lactic acid bacteria; soy powder; viability
• ISSN: 1226-7708; 2092-6456
• DOI: 10.1007/s10068-015-0287-5

Food-grade cryoprotective agents, i.e. , skim milk, soy powder, yeast extract, and trehalose were tested for viability of lactic acid bacteria (LAB, Lactobacillus brevis WK12 and Lactococcus lactis WK11) during freeze drying. Ten percentage of soy powder showed a strong protective effect upon viability of both LAB, showing 1.85×10 11 CFU/mL for L. brevis WK12 and 1.89×10 11 CFU/mL for L. lactis WK11. Microencapsulation in Ca-alginate beads increased viability of LAB, compared to nonencapsulated cells. Moreover, there was a synergetic effect on the stability of LAB when encapsulated LAB in Ca-alginate beads were soaked in 10% of soy powder prior to freeze-drying. When temperature increased, however, survival of LAB decreased. Four weeks after storage the highest viability was observed at -18°C for L. brevis WK12 and L. lactis WK11, showing 1.80×10 11 CFU/mL and 1.78×10 11 CFU/mL, respectively. These results suggest that soy powder may be useful for enhancing viability of LAB with microencapsulation.