Trushenski Jesse T, Lewis Heidi A, Kohler Christopher C
Fisheries and Illinois Aquaculture Center and Department of Zoology, Southern Illinois University Carbondale, Carbondale, IL, 62901-6511, USA,
Lipids. 2008 Jul;43(7):643-53. doi: 10.1007/s11745-008-3190-5. Epub 2008 May 30.
Fatty acid (FA) profile of fish tissue mirrors dietary FA profile and changes in a time-dependent manner following a change in dietary FA composition. To determine whether FA profile change varies among lipid classes, we evaluated the FA composition of fillet cholesteryl esters (CE), phospholipids (PL), and triacylglycerols (TAG) of sunshine bass (SB, Morone chrysops x M. saxatilis) raised on feeds containing fish oil or 50:50 blend of fish oil and coconut, grapeseed, linseed, or poultry oil, with or without implementation of a finishing period (100% FO feed) prior to harvest. Each lipid class was associated with a generalized FA signature, irrespective of nutritional history: fillet PL was comprised largely of saturated FA (SFA), long-chain polyunsaturated FA (LC-PUFA), and total n-3 FA; fillet TAG was higher in MC-PUFA and total n-6 FA; and fillet CE was highest in monounsaturated FA (MUFA). Neutral lipids reflected dietary composition in a near-direct fashion; conversely, PL showed evidence of selectivity for MC- and LC-PUFA. Shorter-chain SFA were not strongly reflected within any lipid fraction, even when dietary availability was high, suggesting catabolism of these FA. FA metabolism in SB is apparently characterized by a division between saturated and unsaturated FA, whereby LC-PUFA are preferentially incorporated into tissues and SFA are preferentially oxidized for energy production. We demonstrated provision of SFA in grow-out feeds for SB, instead MC-PUFA which compete for tissue deposition, meets energy demands and allows for maximum inclusion of LC-PUFA within fillet lipids.
鱼类组织中的脂肪酸（FA）谱反映了饮食中的FA谱，并且在饮食FA组成发生变化后会随时间变化。为了确定FA谱变化在不同脂质类别中是否存在差异，我们评估了在含有鱼油或鱼油与椰子油、葡萄籽油、亚麻籽油或禽油按50:50混合的饲料中饲养的阳光鲈（SB，Morone chrysops x M. saxatilis）鱼片胆固醇酯（CE）、磷脂（PL）和三酰甘油（TAG）的FA组成，收获前有无实施育肥期（100% FO饲料）。无论营养史如何，每种脂质类别都与一种广义的FA特征相关：鱼片PL主要由饱和脂肪酸（SFA）、长链多不饱和脂肪酸（LC-PUFA）和总n-3 FA组成；鱼片TAG中的中链多不饱和脂肪酸（MC-PUFA）和总n-6 FA含量较高；而鱼片CE中的单不饱和脂肪酸（MUFA）含量最高。中性脂质几乎直接反映了饮食组成；相反，PL显示出对MC-PUFA和LC-PUFA有选择性。即使饮食中短链SFA的可利用性很高，它们在任何脂质组分中都没有得到强烈反映，这表明这些FA发生了分解代谢。SB中的FA代谢显然以饱和脂肪酸和不饱和脂肪酸的区分作为特征，即LC-PUFA优先整合到组织中，而SFA优先被氧化以产生能量。我们证明，在SB的育成饲料中提供SFA，而不是竞争组织沉积的MC-PUFA，既能满足能量需求又能使鱼片脂质中最大限度地包含LC-PUFA。
