Abstract Lipids enriched in polyunsaturated fatty acids are very susceptible to oxidation, causing the formation of potentially harmful oxidized products. Hence, it is critical to keep the temperature as low as possible during reaction and storage. In this study, five commercial immobilized lipases were evaluated for their capability to produce novel structured lipids (SLs) enriched with medium-chain fatty acids (MCFAs) through acidolysis of single cell oil (SCO) with capric acid. Among the examined lipases, NS40086 and Lipozyme RM IM showed the highest incorporation degree. The acidolysis reactions resulted in an obvious variation in the fatty acids composition as well as their positional distribution. The obtained SLs contained (33.58 %–34.09 %) capric acid at sn-1, 3 positions with increasing the content of arachidonic acid at the sn-2 position up to (49.82 %–50.25 %). The NS40086 lipase displayed 1, 3 regiospecificity towards the TAG of SCO. The acidolysis reactions using NS40086 lipase resulted in a generation of 23 TAG molecular species containing capric acid. Moreover, the NS40086 lipase was more active than Lipozyme RM IM at relatively low temperatures (35 °C and 40 °C), which could be used effectively as a promising biocatalyst in lipid synthesis.

中文翻译：

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筛选用于从单细胞油中生产新型结构脂质的脂肪酶

摘要富含多不饱和脂肪酸的脂质非常容易氧化，导致形成潜在有害的氧化产物。因此，在反应和储存过程中保持尽可能低的温度是至关重要的。在这项研究中，评估了五种商业固定化脂肪酶通过用癸酸酸解单细胞油 (SCO) 来生产富含中链脂肪酸 (MCFA) 的新型结构脂质 (SL) 的能力。在检查的脂肪酶中，NS40086 和 Lipozyme RM IM 显示出最高的掺入度。酸解反应导致脂肪酸组成及其位置分布的明显变化。获得的 SL 在 sn-1 处含有 (33.58 %–34.09 %) 癸酸，3 个位置，sn-2 位置的花生四烯酸含量增加到 (49.82 %–50.25 %)。NS40086 脂肪酶对 SCO 的 TAG 显示 1、3 区域特异性。使用 NS40086 脂肪酶的酸解反应产生了 23 种含有癸酸的 TAG 分子种类。此外，NS40086 脂肪酶在相对较低的温度（35°C 和 40°C）下比 Lipozyme RM IM 更具活性，可有效用作脂质合成中的有前途的生物催化剂。