Conjugated Linoleic Acid Content and Organoleptic Attributes of Fermented Milk Products Produced with Probiotic Bacteria

Abstract

The effect of probiotic bacteria on the formation of conjugated linoleic acid (CLA), microbial growth, and organoleptic attributes (acidity, texture, and flavor) of fermented milk products was determined. Four probiotic bacteria, Lactobacillus rhamnosus, Propionibacterium freudenreichii subsp. shermanii 56, P. freudenreichii subsp. shermanii 51, and P. freudenreichii subsp. freudenreichii 23, were evaluated individually or in coculture with traditional yogurt cultures (Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus salivarius subsp. thermophilus). The lipid source was hydrolyzed soy oil. L. rhamnosus, in coculture with yogurt culture, resulted in the highest content of CLA. Growth and CLA formation of propionibacteria were enhanced in the presence of yogurt cultures. Texture and flavor attributes of fermented milks produced with propionibacteria were significantly different than the fermented milks processed with yogurt cultures. The fermented milks processed with probiotic bacteria in coculture with yogurt cultures demonstrated similar acidity, texture, and flavor as the fermented milk produced with yogurt cultures.

Dairy Propionibacteria: Less Conventional Probiotics to Improve the Human and Animal Health

“…freudenreichii) [96,97] and cutaneous propionibacteria (P. acnes) [98] produce cis-9, trans-11 and trans-10, cis-12, the major isomers with biological activity, on different growth media: culture broths [97], lipid containing plant materials [99], milk and ripening cheese [100].…”

“…Besides, it has been observed that CLA formation and growth of dairy propionibacteria in fermented milks were enhanced in the presence of yogurt microorganisms whereas organoleptic attributes obtained with yogurt starter cultures were not affected by co-cultures with the propionibacteria [100].…”

Influence of processing on the fatty acid composition and the content of conjugated linoleic acid in organic and conventional dairy products - a review

“…I). Xu et al [84] applied a selected strain of Lactobacillus rhamnosus and the same strains of Propionibacteria freudenreichii for the production of fermented milk. Their corresponding work is presented in Section 5.…”

Increased CLA content in organic milk fermented by bifidobacteria or yoghurt cultures

“…For example, propionibacteria (i.e. as adjunct culture and possibly lactic acid bacteria) [28] and some yoghurt starter cultures [7,37] showed potential as food-grade organisms to be used for CLA enhancement in dairy products. In yoghurt, there is a certain potential to increase the CLA content by adding adjunct cultures under the condition that free linoleic acid or oil and suitable lipase are added; this approach of increasing the CLA level in the fermented milk has its limitation(s) [37].…”

“…as adjunct culture and possibly lactic acid bacteria) [28] and some yoghurt starter cultures [7,37] showed potential as food-grade organisms to be used for CLA enhancement in dairy products. In yoghurt, there is a certain potential to increase the CLA content by adding adjunct cultures under the condition that free linoleic acid or oil and suitable lipase are added; this approach of increasing the CLA level in the fermented milk has its limitation(s) [37]. The substrate level in the growth media may be a key factor for CLA production, since a high level of unsaturated long-chain fatty acids (LCFA) is believed to be inhibitory not only to cell growth but also to the overall biohydrogenation steps, especially for gram-positive bacteria, which lack an outer membrane [21].…”