33G-4 |
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K. J. Jung1, C. G. Park2, S. J. Kim1, S. W. Hyung1, M. S. Kim1, C. W. Park1, Y. S. Kim1, J. O. Kim3, and Y. L. HA1. (1) Division of Applied Life Science (BK21), Graduate School, Gyeongsang National University, Jinju, 660-701, South Korea, (2) Applied Biological Science, Gyeongsang National University, Jinju, 660-701, South Korea, (3) HK Biotech CO., Ltd., Jinju, 660-902, South Korea Conjugated linoleic acid (CLA) is available as forms of free CLA (FR-CLA), triglyceride CLA (TG-CLA) and phospholipid CLA (PL-CLA). FR-CLA was produced from linoleic acid by alkaline isomerization methods. Currently, TG-CLA and PL-CLA were produced from experimental animals and fishes by feeding FR-CLA. It is of significance to figure out whether or not silkworms accumulate dietary CLA in their body fats. Our objective was to figure out CLA accumulation in TG and PL of silkworm by dietary FR-CLA. FR-CLA (47% c9,t11 CLA and 45% t10,c12 CLA) was synthesized from linoleic acid by alkaline isomerization. Silkworm larvae were fed fresh mulberry leaves, and switched to one of the following mulberry leaves at 4th stages: control leaves, mulberry leaves sprayed various concentration of FR-CLA solution in acetone (designated CLA leaves), or mulberry leaves sprayed 10% safflower oil (10% SO leaves; positive control). At the 3rd day of 5th instar stage, silkworms were sacrificed, and body tissue samples were prepared by removing intestinal tracts containing foodstuffs, and haemolymphs. Body tissues were freeze-dried and used for the analysis of lipids and CLA contents CLA leaves treatment reduced body weights and total lipid contents of silkworms, but increased CLA content in lipids, as a dose-dependent manner. Among CLA leave treatments, 10% CLA leaves treatment produced the highest amount of CLA; 29 mg CLA/197 mg lipids/silkworm, as compared to 1% CLA leaves treatment (1.9 mg CLA/203 mg lipids/silkworm). Approximately 99% of CLA was present in TG-CLA fraction and less than 0.1% CLA was in PL-CLA fraction. A similar ratio of c9,t11 CLA to t10,c12 CLA was present in TG-CLA, but the ratio was approximately a 6.5:3.5 in PL-CLA. No CLA was detected in body tissues of control or treated with 10% SO leaves. These results indicate that substantial amount of CLA is incorporated into TG fraction of silkworms, and suggest that 10% CLA was suitable concentration of rearing silkworms for the purpose of CLA production.
Session 33G, Nutraceuticals & Functional Foods: Lipid and probiotic functional foods
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