Studies on N-Terminal Glycation of Peptides in Hypoallergenic Infant Formulas: Quantification of -N-(2-Furoylmethyl) Amino Ac
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- 作者：Ilka Penndorf ; Daniela Biedermann ; Sarah V. Maurer ; and ; Thomas Henle
- 刊名：Journal of Agricultural and Food Chemistry
- 出版年：2007
- 出版时间：February 7, 2007
- 年：2007
- 卷：55
- 期：3
- 页码：723 - 727
- 全文大小：79K
- 年卷期：v.55,no.3(February 7, 2007)
- ISSN：1520-5118
文摘
To obtain information about the extent of the early Maillard reaction between the N-termini of peptidesand lactose, 
-N-(2-furoylmethyl) amino acids (FMAAs) were quantified together with 
-N-(2-furoylmethyl)lysine (furosine) in acid hydrolyzates of hypoallergenic infant formulas, conventional infantformulas, and human milk samples using RP-HPLC with UV-detection. FMAAs are formed duringacid hydrolysis of peptide-bound N-terminal Amadori products (APs), and furosine is formed fromthe Amadori products of peptide-bound lysine. Unambiguous identification was achieved by meansof LC/MS and UV-spectroscopy using independently prepared reference material. The extent of acid-induced conversion of APs to FMAAs was studied by RP-HPLC with chemiluminescent nitrogendetection (CLND). Depending on the corresponding -N-lactulosyl amino acid, between 6.0% and18.1% of FMAAs were formed during hydrolysis for 23 h at 110 
C in 8 N HCl. From -N-lactulosyllysine, 50% furosine is formed under these conditions. Whereas furosine was detectable inall assayed samples, five different FMAAs, -FM-Lys, -FM-Ala, -FM-Val, -FM-Ile, and -FM-Leu, were exclusively detected in acid hydrolyzates of hypoallergenic infant formulas in amountsranging from 35 to 396 
mol/100 g protein. Taking the conversion factors into account, modificationof N-terminal amino acids in peptides by reducing carbohydrates was between 0.3% and 8.4%. Thishas to be considered within the discussion concerning the nutritional quality of peptide-containingfoods.
-N-(2-furoylmethyl) amino acids (FMAAs) were quantified together with -N-(2-furoylmethyl)lysine (furosine) in acid hydrolyzates of hypoallergenic infant formulas, conventional infantformulas, and human milk samples using RP-HPLC with UV-detection. FMAAs are formed duringacid hydrolysis of peptide-bound N-terminal Amadori products (APs), and furosine is formed fromthe Amadori products of peptide-bound lysine. Unambiguous identification was achieved by meansof LC/MS and UV-spectroscopy using independently prepared reference material. The extent of acid-induced conversion of APs to FMAAs was studied by RP-HPLC with chemiluminescent nitrogendetection (CLND). Depending on the corresponding -N-lactulosyl amino acid, between 6.0% and18.1% of FMAAs were formed during hydrolysis for 23 h at 110 C in 8 N HCl. From -N-lactulosyllysine, 50% furosine is formed under these conditions. Whereas furosine was detectable inall assayed samples, five different FMAAs, -FM-Lys, -FM-Ala, -FM-Val, -FM-Ile, and -FM-Leu, were exclusively detected in acid hydrolyzates of hypoallergenic infant formulas in amountsranging from 35 to 396 mol/100 g protein. Taking the conversion factors into account, modificationof N-terminal amino acids in peptides by reducing carbohydrates was between 0.3% and 8.4%. Thishas to be considered within the discussion concerning the nutritional quality of peptide-containingfoods.