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

Abstract

-This study investigates the kinetics of acidification, fatty acid (FA) profile and conjugated linoleic acid (CLA, C18:2 c9, t11) content in fermented milks prepared from organic and conventional milk. Fermented milks were manufactured with five mixed cultures: four different strains of Bifidobacterium animalis subsp. lactis (BL04, B94, BB12 and HN019) and Lactobacillus delbrueckii subsp. bulgaricus LB340, in co-culture with Streptococcus thermophilus TA040. The composition of milk was evaluated, and the kinetics of acidification was followed by continuous pH measurement using the Cinac system. The profile of FA, including CLA, was analyzed by gas chromatography. The chemical composition of conventional and organic milk was similar, with the exception of protein and Fe, the concentrations of which were higher in the organic milk. The rate of acidification was significantly influenced by the type of milk and the bacterial strain used. Co-cultures St-HN019 and St-BB12 showed higher maximal acidification rates in both milks. Final counts of S. thermophilus (9.0-10.1 log 10 colony forming units (CFU)·mL −1 ), Lactobacillus bulgaricus (8.2-8.5 log 10 CFU·mL −1 ) and B. animalis subsp. lactis strains (8.3-9.3 log 10 CFU·mL −1 ) did not differ significantly in either milk. Unexpectedly, all fermented organic milks contained significantly higher amounts of CLA than the same milk before fermentation, whereas CLA amounts did not change during fermentation of conventional milk. Regardless of the type of milk, CLA was found to be significantly positively correlated with trans-vaccenic acid and negatively correlated with linoleic acid. Moreover, the CLA contents were significantly higher in fermented milks showing shorter fermentation times. acidification profile / fermented milk / Bifidobacterium animalis subsp. lactis / organic milk / conjugated linoleic acid / trans-vaccenic acid Article published by EDP Sciences 料乳中，St-HN019 和 St-BB12 共发酵菌株表现出最大的酸化速率; S. thermophilus (9.0 10.1 log 10 cfu·mL −1 )、L. bulgaricus (8.2 8.5 log 10 cfu·mL −1 ) 和 B. animalis subsp. lactis strains (8.3 9.3 log 10 cfu·mL −1 ) 在两种乳中的最后菌数没有显著差异○ 出乎意料的是有机乳发 酵后 CLA 含量显著地提高，但是普通乳发酵前后 CLA 含量没有变化○ 如果不考虑乳的 类型，CLA 含量与反式-十八碳烯酸呈正相关，与亚油酸含量呈负相关○ 此外，发酵时 间短的发酵乳中 CLA 含量较高○ 酸化特性 / 益生性发酵乳 / 有机乳 / 共轭亚油酸 / 反式-十八碳烯酸 Résumé -Teneur en acide linoléique conjugué accrue dans des laits biologiques fermentés par des bifidobactéries et des levains à yaourt. Cette étude a pour but d'examiner les cinétiques d'acidification, les profils en acides gras et les teneurs en acide linoléique conjugué (CLA, C18:2 c9, t11) de laits fermentés préparés à partir de lait biologique et conventionnel. Des laits fermentés ont été produits avec cinq types de cultures mixtes : quatre souches de Bifidobacterium animalis subsp. lactis (BL04, B94, BB12 et HN019) et Lactobacillus delbrueckii subsp. bulgaricus LB340, en co-culture avec S. thermophilus TA040. La composition du lait était évaluée et les cinétiques d'acidification étaient suivies par mesure continue du pH à l'aide du système C...

Fatty acid profile, trans-octadecenoic, α-linolenic and conjugated linoleic acid contents differing in certified organic and conventional probiotic fermented milks

“…The percentage of PUFA increased during fermentation in organic milk ($0.2%) but remained stable in conventional milk. These results are in agreement with those obtained by Florence et al (2009) with the cultures of S. thermophilus and four strains of B. lactis. They could be explained either by the different balance with MUFA or SFA, or by the synthesis of some polyunsaturated fatty acids by the bacteria (Oh et al, 2003).…”

“…To our knowledge, only the work of Florence et al (2009) describes the acidification profile, fatty acids contents, and chemical composition of organic and conventional milks fermented by bifidobacteria in co-culture with Streptococcus thermophilus. These authors detected higher protein and iron concentrations in organic fermented milks, although no difference was observed in the initial milk.…”

Bioactive milk proteins, peptides and lipids and other functional components derived from milk and bovine colostrum

“…Bisig et al (2007) have suggested that dairy products could be enriched with CLA produced in a special culture medium. Recently, Florence et al (2009) demonstrated that organic milks fermented with several strains of bifi dobacteria and yoghurt cultures contained signifi cantly higher amounts of CLA than the same milk before fermentation, whereas CLA amounts did not change during fermentation of conventional milk. Supplementation of milk with different prebiotic compounds has been shown to further stimulate production of CLA by probiotic bacteria .…”

Açai pulp addition improves fatty acid profile and probiotic viability in yoghurt

“…Studies show that CLA can be produced by some strains of lactobacilli, bifidobacteria and propionibacteria from linoleic acid (Ekinci et al, 2008;Ogawa et al, 2005;Yadav et al, 2007;Florence et al, 2009). Alonso, Cuesta, and Gilliland (2003), Ekinci et al (2008), and Prandini, Sigolo, Tansini, Brogna, and Piva (2007) reported health benefits attributed to CLA, such as protection against arteriosclerosis, modulation of immune system, and body fat reduction.…”