Deposition of conjugated linoleic acid (CLA) in Nile tilapia

This study was carried out to determine the deposition of conjugated linoleic acid (CLA) in Nile tilapia Oreochromis niloticus fillet. Fish averaging 121.08 +/- 8.48 g were distributed in four cement amianthus tank (1.0 m (3) each) and hand fed to apparent satiation, two times a day for 49 days. As feed, an extruded commercial diet with 28% CP and 3000 kcal of digestible energy was utilized. A commercial CLA product (Luta-CLA (R), BASF) was added at 2% of the diet. At the beginning of the experiment, five fish were randomly collected as a control sample ( without CLA). Weekly, two fish of each tank were collected, weighed and filleted for measurement of CLA deposition ratio in the fillets. The fillet samples were stored at-24 degrees C for total lipid and analyses of fatty acids profiles. The deposition rate of CLA was determined by Gompertz function (y = a. exp{-b. exp[-kt]}). Half time ( T) to have 50% deposition of CLA was calculated by the equation T = 1n2/k, where T is half time; ln is Napierian logarithm and constant k the time unit, which provides the "velocity" in the deposition of CLA in the Nile tilapia fillets. The maximum CLA deposition in the fish fillet lipids, estimated by the Gompertz function, was 1.61 g/100 g fillets lipids. Half time of CLA deposition in the fillet lipids occur within 6.86 days.