Moughan Paul J, Rutherfurd Shane M
Massey University, Riddet Institute, Private Bag 11 222, Palmerston North, New Zealand.
J AOAC Int. 2008 Jul-Aug;91(4):901-6.
A brief historical overview is presented on the development of the science addressing lysine bioavailability in foods. Early observations that dietary protein utilization did not always correlate with gross amino acid composition led to an understanding that the amino acid lysine, in particular, can be easily damaged during food processing. Conventional amino acid analysis, involving a strong acid hydrolysis step, can lead to a significant degree of overestimation of lysine in processed foods. More recently, it has been found that not only food lysine content values but also estimates of lysine digestibility and digestible lysine contents may be erroneous. Estimates of absorbed (true ileal digestible) reactive lysine are accurate measures of available lysine. Technically, bioassays such as the slope-ratio assay determine utilized rather than available lysine.
本文简要回顾了食品中赖氨酸生物利用率相关科学的发展历程。早期观察发现，膳食蛋白质利用率并不总是与总氨基酸组成相关，这使人们认识到，特别是氨基酸赖氨酸在食品加工过程中很容易被破坏。传统的氨基酸分析包括强酸水解步骤，这可能导致对加工食品中赖氨酸的严重高估。最近发现，不仅食品赖氨酸含量值，而且赖氨酸消化率和可消化赖氨酸含量的估计值都可能有误。吸收的（真回肠可消化）活性赖氨酸的估计值是可用赖氨酸的准确衡量指标。从技术上讲，诸如斜率比测定法等生物测定法测定的是已利用的赖氨酸而非可用赖氨酸。
