Bioconversion of linoleic acid into conjugated linoleic acid by lactic acid bacteria isolated from cheese

Abstract

Conjugated linoleic acids (CLA) are a mixture of positional and geometric isomers of linoleic acid (cis-9, cis-12 octadecadienoic acid) with conjugated double bounds. Their principal dietary sources include ruminant and dairy fats, and CLA are shown to possess health beneficial effects on human health. Dairy cultures may biologically convert linoleic acid to CLA, but their capability is affected by several factors such as the source and amount of linoleic acid in medium and fermentation conditions. The objective of this study is to determine the ability of lactic cultures isolated from different cheeses to produce CLA from sunflower oil as a natural source of linoleic acid. Results indicated that three strains of Lactobacillus and two strains of Enterococcus were able to increase CLA concentration more than 30% based on the weight of sunflower oil added to model medium. It is recommended that the bioconversion capability of linoleic acid into CLA by these strains should be determined in actual dairy products.