Manufacturing of fermented goat milk with a mixed starter culture of Bifidobacterium animalis and Lactobacillus acidophilus in a controlled bioreactor

• Published in: Letters in applied microbiology Vol. 42; no. 6; pp. 595 - 599
• Main Authors: Kongo, J.M, Gomes, A.M, Malcata, F.X
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01-06-2006; Blackwell Publishing Ltd
• Subjects: Animals; Bifidobacterium; Bifidobacterium - growth & development; Bifidobacterium animalis; bioreactor; Bioreactors; cold storage; Colony Count, Microbial; Culture Media; cultured milk starters; Fermentation; fermented milk; Food Microbiology; goat milk; Goats; Hydrogen-Ion Concentration; lactic fermentation; Lactobacillus; Lactobacillus acidophilus; Lactobacillus acidophilus - growth & development; Milk - microbiology; multiple strain starters; Probiotics; Refrigeration; survival; temperature; viability
• ISSN: 0266-8254; 1472-765X; 1365-2673
• DOI: 10.1111/j.1472-765X.2006.01882.x

This work was undertaken to study the feasibility and the characteristics of a fermented product made of goat milk, using a mixed starter culture of Bifidobacterium animalis and Lactobacillus acidophilus under controlled conditions, and to determine their survival in the fermented milk during refrigerated storage. Goat milk was inoculated with Lact. acidophilus and Bif. animalis mixed starter, fermented in a glass bioreactor with controlled temperature (37°C) and anaerobiosis, and monitored for growth and acidification. The fermented milk was then stored for 10 days under refrigeration, and monitored daily for starter microflora survival and pH changes. Lact. acidophilus viable counts reached a maximum of 7·1 x 10⁸ colony-forming units (CFU) ml⁻¹, and Bif. animalis a maximum of 6·3 x 10⁷ CFU ml⁻¹ by 20 h of fermentation. During refrigerated storage, both strains exhibited a good survival, with viable numbers remaining essentially constant throughout the experiment, whereas the pH of the fermented milk dropped slightly. Mixed cultures of Bif. animalis and Lact. acidophilus may be used to produce fermented goat milk with high counts of both probiotic strains. Goat milk fermented with Bif. animalis and Lact. acidophilus can be manufactured as an alternative probiotic dairy product.