Conjugated linoleic acid concentration as affected by lactic cultures and additives

Six lactic cultures: Lactobacillus acidophilus (CCRC14079), L. delbrueckii subsp. bulgaricus (CCRC14009), L. delbrueckii subsp. lactis (CCRC14078), Lactococcus lactis subsp. cremoris (CCRC12586), Lc. lactis subsp. lactis (CCRC10791), and Streptococcus thermophilus (CCRC12257) were tested for the effects of additions of 60 g l−1 sucrose, lactose, fructose, and 10 g l−1 sodium chloride. The levels of c9,t11-conjugated linoleic acid (c9,t11-CLA) formed were determined by gas chromatography. A significant decrease in c9,t11-CLA level was observed in cultures with sucrose, lactose, fructose, and sodium chloride added, except for Lc. lactis subsp. cremoris. Inoculation of L. acidophilus into 60 g l−1 sweeteners and 10 g l−1 sodium chloride-treated skim milk medium under aerobic conditions for 24 h incubation was most effective in promoting c9,t11-CLA formation. Lactose and fructose are suggested for use in maintaining a high CLA level.