脂肪酶对油脂体外降解及消化的研究

Effect of lipase on degradation and digestibility of oil and fat in vitro

以大豆油、菜籽油、棕榈油、鸭油和猪油的乳化油脂为原料,测定添加脂肪酶后油脂的水解效果,并进行体外模拟猪胃肠道消化试验,观察乳仔猪料添加脂肪酶后消化率的变化。结果表明:乳化油脂中添加脂肪酶反应4 h即可达到降解峰值,当脂肪酶酶活剂量达到200 U/mL(以原始油脂体积计)时,不同油脂产生的脂肪酸量均可达到饱和;在添加不同剂量脂肪酶阶段,棕榈油和猪油乳化油脂产生的脂肪酸量始终大于大豆油和鸭油乳化油脂的,菜籽油乳化油脂的最低,组间差异显著(P<0.05);与空白不加酶组相比,所有乳化油脂加酶(酶活剂量为260 U/mL)后产生的脂肪酸总增加量均超过1.50 mmol/L,总增加率均超过300%,其中以菜籽油的提升最高,达到了810.5%。模拟乳仔猪消化过程也发现,当脂肪酶(酶活80 000 U/g)添加量为125 g/t(以饲料质量计)时,饲料干物质消化率和能量消化率可提高0.86个百分点和0.83个百分点,鉴于饲料中其他组成原料也含有一定的脂肪,故脂肪酶添加量略高于125 g/t或与其他酶进行搭配使用效果可能更佳。

Using emulsified soyabean oil, rapeseed oil, palm oil, duck fat and lard as raw materials, the hydrolysis effect on the oil and fat added with lipase was determined, the in vitro simulated pig gastrointestinal digestion test was conducted to survey changes of digestibility of piglets added with lipase. The results showed that the emulsified oil and fat reached their degradation peak when reacted for 4 h. The fatty acid produced by different oils and fats reached saturated when added with 200 U/mL lipase(on the basis of oil volume), and fatty acid contents produced by palm oil and lard were higher(P<0.05) than those of soybean oil and duck fat, while rapeseed oil was the lowest. The total amount of increased fatty acid in different emulsified oil and fat groups added with lipase were more than 1.50 mmol/L,as well as total growth rate all exceeded 300%. Even rapeseed oil increased by 810.5%,which was the highest. Moreover, the dry matter digestibility and energy digestibility of piglet added with a 125 g/t lipase(enzyme activity 80 000 U/g) were respectively improved by 0.86 percentage points and 0.83 percentage points during the simulated gastrointestinal digestion of pig. But in consideration of lipid contained in other ingredients, the dosage of lipase slightly above 125 g/t or together with other enzyme were prefered.