Glutamine in commercial liquid nutritional products

被引：17

作者：

Baxter, JH ^{[1
]}

Phillips, RR ^{[1
]}

Dowlati, L ^{[1
]}

Johns, PW ^{[1
]}

机构：

[1] Abbott Labs, Ross Prod Div, Columbus, OH 43219 USA

来源：

JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY | 2004年 / 52卷 / 16期

关键词：

glutamine; pyroglutamic acid; enzyme hydrolysis; nutritional products; HPLC;

D O I：

10.1021/jf049627h

中图分类号：

S [农业科学];

学科分类号：

09 [农学];

摘要：

Total glutamine concentrations in commercial nutritional products have been determined by enzymatic hydrolysis followed by HPLC quantification of free glutamine and free pyroglutamic acid. Hydrolysis was accomplished by a published three-enzyme (Pronase, leucine aminopeptidase, prolidase), 20-h/37 degreesC digestion. Glutamine was determined as its FMOC derivative by reverse phase HPLC-fluorescence, and pyroglutamic acid was determined directly by organic acid HPLC-UV. Approximately 4.11% of the released glutamine is converted to pyroglutamic acid during the 20-h digestion. Experimental ratios of enzyme hydrolysis glutamine to acid hydrolysis glutamic acid + glutamine + pyroglutamic acid (GLX) indicate that the method recovers >90% of the protein-bound glutamine. The nutritional products with casein dominant intact protein systems typically deliver >9 g of glutamine/100 g of protein, or similar to40 g of glutamine/100 g of GLX.

引用

页码：4963 / 4968

页数：6

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