Release of β-casomorphins 5 and 7 during simulated gastro-intestinal digestion of bovine β-casein variants and milk-based infant formulas
Release of β-casomorphins 5 and 7 during simulated gastro-intestinal digestion of bovine β-casein variants and milk-based infant formulas
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DOI：
10.1016/j.foodchem.2008.02.077
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发表时间：
2008-10-15
期刊：
影响因子：
8.8
通讯作者：
De Noni, Ivano
中科院分区：
文献类型：
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作者：
De Noni, Ivano
研究了牛β-酪蛋白变体（n = 3）、商业乳基婴儿配方食品（n = 6）和实验性婴儿配方食品（n = 3）在模拟胃肠消化（SGID）期间β-酪啡肽-5（BCM 5）和β-酪啡肽-7（BCM 7）的释放。SGID包括在pH 2.0、3.0和4.0下的胃蛋白酶消化和用Corolase PP（TM）进一步水解。β-酪蛋白（β-CN）变体从来自Holstein-Friesian和Jersey品种的奶牛的生乳中提取。从牛奶中分离基因组DNA，并通过基于PCR的方法确定β-CN基因型。通过毛细管区带电泳确定蛋白质水平的表型，以确定基因表达水平。BCM的识别和定量涉及HPLC与串联MS偶联。无论pH如何，从β-CN的变体A1和B（5-176 mmol/mol酪蛋白）生成的BCM 7在形式B的SGID期间释放的量最高。如所预期的，在SGID的任何步骤，肽都没有从变体A2释放。在SGID过程中，无论遗传变异或pH值如何，在水解产物中均不形成BCM 5。提交给SGID的所有商用婴儿配方奶粉中都含有乙型氯化萘变体A1、A2和B。因此，从800 ml IF中释放16-297 nmol BCM 7，即婴儿每日推荐摄入量。工业间接UHT处理（156 ℃ × 6-9 s）没有改变BCM 7的释放，并且在SGID期间，在原始制剂和最终热处理的IF中形成相当的肽量。(C)2008爱思唯尔有限公司保留所有权利。
The release of beta-casomorphin-5 (BCM5) and beta-casomorphin-7 (BCM7) was investigated during simulated gastro-intestinal digestion (SGID) of bovine beta-casein variants (n = 3), commercial milk-based infant formulas (n = 6) and experimental infant formulas (n = 3). SGID included pepsin digestion at pH 2.0, 3.0 and 4.0 and further hydrolysis with Corolase PP (TM). beta-Casein (beta-CN) variants were extracted from raw milks coming from cows of Holstein-Friesian and Jersey breeds. Genomic DNA was isolated from milk and the beta-CN genotype was determined by a PCR-based method. Phenotype at protein level was determined by capillary zone electrophoresis in order to ascertain the level of gene expression. Recognition and quantification of BCMs involved HPLC coupled to tandem MS. Regardless of the pH, BCM7 generated from variants A1 and B of beta-CN (5-176 mmol/mol casein) the highest amount being released during SGID of form B. As expected, the peptide was not released from variant A2 at any steps of SGID. BCM5 was not formed in hydrolysates irrespective of either the genetic variant or the pH value during SGID. Variants A1, A2 and B of beta-CN were present in all the commercial infant formulae (IFs) submitted to SGID. Accordingly, 16-297 nmol BCM7 were released from 800 ml IF, i.e. the daily recommended intake for infant. Industrial indirect-UHT treatments (156 degrees C x 6-9 s) did not modify release of BCM7 and, during SGID, comparable peptide amounts formed in raw formulation and final heat-treated IFs. (C) 2008 Elsevier Ltd. All rights reserved.