title: Bacterial production of conjugated linoleic and linolenic Acid in foods: a technological challenge.
abstract: Conjugated linoleic acid (CLA) and conjugated linolenic acid (CLNA) isomers are present in foods derived from ruminants as a result of the respective linoleic acid (LA) and α-linolenic acid (LNA) metabolism by ruminal microorganisms and in animals' tissues. CLA and CLNA have isomer-specific, health-promoting properties, including anticarcinogenic, antiatherogenic, anti-inflammatory, and antidiabetic activity, as well as the ability to reduce body fat. Besides ruminal microorganisms, such as Butyrivibrio fibrisolvens, many food-grade bacteria, such as bifidobacteria, lactic acid bacteria (LAB), and propionibacteria, are able to convert LA and LNA to CLA and CLNA, respectively. Linoleate isomerase activity, responsible for this conversion, is strain-dependent and probably related to the ability of the producer strain to tolerate the toxic effects of LA and LNA. Since natural concentrations of CLA and CLNA in ruminal food products are relatively low to exert their health benefits, food-grade bacteria with linoleate isomerase activity could be used as starter or adjunct cultures to develop functional fermented dairy and meat products with increased levels of CLA and CLNA or included in fermented products as probiotic cultures. However, results obtained so far are below expectations due to technological bottlenecks. More research is needed to assess if bacterial production kinetics can be increased and can match food processing requirements.
authors.affiliation: a Laboratory for Animal Nutrition and Animal Product Quality, Department of Animal Production, Ghent University , B-9090 Melle, Belgium .
authors.forename: Lara
authors.initials: L
authors.lastname: Gorissen
authors.forename: Frédéric
authors.initials: F
authors.lastname: Leroy
authors.forename: Luc
authors.initials: L
authors.lastname: De Vuyst
authors.forename: Stefaan
authors.initials: S
authors.lastname: De Smet
authors.forename: Katleen
authors.initials: K
authors.lastname: Raes
mesh_terms: D001644:Bifidobacterium / Q000378:metabolism*; D003611:Dairy Products; D005285:Fermentation; D044243:Linoleic Acids, Conjugated / Q000096:biosynthesis; D008461:Meat Products; D019936:Probiotics; D017962:alpha-Linolenic Acid / Q000096:biosynthesis*
chemical_list: D044243:Linoleic Acids, Conjugated; D017962:alpha-Linolenic Acid
keywords: Conjugated linoleic acid; fermented foods; food-grade bacteria; ruminal biohydrogenation