A new method for determining digestible reactive lysine in foods
A new method for determining digestible reactive lysine in foods
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DOI：
10.1021/jf950032j
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发表时间：
1996-08-01
影响因子：
6.1
通讯作者：
Rutherfurd, SM
中科院分区：
文献类型：
--
作者：
Moughan, PJ;Rutherfurd, SM
本研究旨在建立一种测定加工饲料中可消化活性赖氨酸的生物测定法。该方法结合了测定反应性赖氨酸（胍基化法）的饮食和restasta与真正的回肠赖氨酸消化率测定。使用优化的反应条件，反应性赖氨酸测定未加热的酪蛋白和加热的乳糖/酪蛋白使用胍基化和FDNB方法。两种方法获得的值相似（酪蛋白和加热乳糖/酪蛋白分别为0.53和0.32 mmol（g酪蛋白）（-1））。传统的赖氨酸分析高估了加热混合物中的活性赖氨酸（0.38 mmol g（-1））。酪蛋白中赖氨酸的回肠真消化率为98.8%。加热乳糖/酪蛋白中的相应值为70.5%，而真实回肠反应性赖氨酸消化率为85.9%。确定加工食品中可消化赖氨酸的传统方法似乎大大低估了赖氨酸消化率。新的方法，它允许测定可消化的活性赖氨酸，避免了传统方法中固有的一些问题。
The study aimed to develop a bioassay for determining digestible reactive lysine in processed feedstuffs. The approach combines the determination of reactive lysine (guanidination method) in diets and digesta with a true ileal lysine digestibility assay. Using optimized reaction conditions, reactive lysine was determined in unheated casein and heated lactose/casein using both guanidination and FDNB methods. Similar values were obtained with both methods (0.53 and 0.32 mmol (g of casein)(-1) for casein and heated lactose/casein, respectively). Conventional lysine analysis overestimated (0.38 mmol g(-1)) the reactive lysine in the heated mixture. The true ileal lysine digestibility in casein was 98.8%. The corresponding value in the heated lactosa/casein was 70.5%, whereas the true ileal reactive lysine digestibility was 85.9%. The traditional approach to determining the digestible lysine in processed foods appears to considerably underestimate lysine digestibility. The new method, which allows determination of digestible reactive lysine, circumvents some problems inherent in the traditional approach.