Selection of Lactic Acid Bacteria for the Optimized Production of Sheep’s Milk Yogurt with a High Conjugated Linoleic Acid Content

Gabriela Christina Kuhl, Ana Paula Gusso, Brenda Lee Simas Porto, Carmen Maria Olivera Müller, Ricardo Ruiz Mazzon, Marcone Augusto Leal de Oliveira, Neila Silvia Pereira dos Santos Richards, Juliano De Dea Lindner


Thirty-five different lactic acid bacteria (LAB) strains were screened for their conjugated linoleic acid (CLA) isomers (C18:2 cis-9, trans-11 and C18:2 trans-10, cis-12) producing ability from linoleic acid (LA) in sheep’s milk. Preliminary experiments revealed that Lactobacillus delbrüeckii ssp. bulgaricus 2230 and Streptococcus thermophilus St 360 among the screened strains had the highest CLA-producing ability. This two strains were assayed in an 11-run fractional factorial design to investigate the effect of four variables included glucose, powdered sheep milk, LA and inoculum ratio on CLA production in a sheep’s milk yogurt. The optimum conditions for producing the highest levels of CLA (42.86%) were obtained by adding 10.00 mg/mL of glucose, 30.00 mg/mL of powdered sheep milk, 0.90 mg/mL of LA and a 1:2 (St:Lb) ratio of bacterial strains in the inoculum. This CLA-rich sheep’s milk yogurt could be an important supplementary food source for increasing the CLA in the human diet. 


dairy product, functional food, Lactobacillus delbrueckii ssp. bulgaricus, Streptococcus thermophilus

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Copyright (c) 2017 Juliano De Dea Lindner

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Journal of Food Research   ISSN 1927-0887 (Print)   ISSN 1927-0895 (Online)  E-mail:

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