17A-8 |
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T. Y. LIN, Animal Science Department, Chinese Culture University, 55 Hwa Kang Rd, Taipei, 111, Taiwan Conjugated linoleic acid (CLA), the product of linoleic acid isomerization, is gaining interest due to its biological activity. Several lactic cultures were observed capable of converting linoleic acid into CLA, due to the presence of linoleic acid (LA) isomerase. A desaturase which could convert oleic acid into CLA was found in cheddar cheese and a plant. However, the effect of fatty acids other than LA on CLA production by lactic cultures has not been reported. The objective of the study was to determine the effect of fatty acid additions to Lactobacillus delbrueckii ssp. bulgaricus (CCRC14009) on CLA production. A 1.15 g aliquot of L. delbrueckii ssp. bulgaricus separated from MRS broth after incubation was mixed with 0.065 g BSA and one of the three fatty acids: 0.13 g linoleic acid, oleic acid, and linolenic acid in 3.655 ml pH 6.5 phosphate buffer. After incubated at 37°C for 108 hr, CLA concentration was quantified by HPLC. Enzyme extract from the culture was also reacted with LA at 50°C for 10min at pH 5. Results showed that linoleic acid addition to the culture improved total CLA production, indicating the presence of LA isomerase activity in the culture, and the isomer levels of 10t,12t- and 10t,12c-CLA were higher in LA treatment than in other treatments. The enzyme extract from L. delbrueckii ssp. bulgaricus was observed capable of oleic acid conversion into CLA, demonstrating the presence of desaturase activity in the enzyme extract of the culture.
Session 17A, Dairy Foods: Cheese and microbiology
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