Development of Stable Isotope Dilution Assays for the Quantitation of Amadori Compounds in Foods

Abstract

During thermal processing of foods, reducing carbohydrates and amino acids may form 1-amino-1-desoxyketoses named Amadori rearrangement products after the Italian chemist Mario Amadori. Although these compounds are transient intermediates of the Maillard reaction, they are often used as suitable markers to measure the extent of a thermal food processing, such as for spray-dried milk or dried fruits. Several methods are already available in the literature for their quantitation, but measurements are often done with external calibration without addressing losses during the workup procedure. To cope with this challenge, stable isotope dilution assays in combination with LC-MS/MS were developed for the glucose-derived Amadori products of the seven amino acids valine, leucine, isoleucine, phenylalanine, tyrosine, methionine, and histidine using the respective synthesized [(13)C6]-labeled isotopologues as internal standards. The quantitation of the analytes added to a model matrix showed a very good sensitivity with the lowest limits of detection for the Amadori compound of phenylalanine of 0.1 μg/kg starch and 0.2 μg/kg oil, respectively. Also, the standard deviation measured in, for example, wheat beer was only ±2% for this analyte. Application of the method to several foods showed the highest concentrations of the Amadori product of valine in unroasted cocoa (342 mg/kg) as well as in dried bell pepper (3460 mg/kg). In agreement with literature data, drying of foods led to the formation of Amadori products, whereas they were degraded during roasting of, for example, coffee or cocoa. The study presents for the first time results on concentrations of the Amadori compounds of tyrosine and histidine in foods.

Simultaneous quantification of ten Amadori compounds in tobacco using liquid chromatography with tandem mass spectrometry

“…For example, in 2014, Meitinger et al. quantified seven Amadori compounds in cocoa beans including Fru‐Leu and Fru‐Lle, but the two isomers coeluted in a single peak . In 2014, Wanhong Zhou et al.…”

“…Until 2 years ago, Amadori compounds in complex matrices such as foods and tobacco were quantified using HPLC-MS/MS. For example, in 2014, Meitinger et al quantified seven Amadori compounds in cocoa beans including Fru-Leu and Fru-Lle, but the two isomers coeluted in a single peak [14]. In 2014, Wanhong Zhou et al quantified two important Amadori compounds in cigarettes [15].…”

Fructosyl-Valine Orally Administrated to Chickens is Absorbed from Gastrointestinal Tract

“…This reaction can be easily taken place not only in the body but also in foods (Meitinger et al, 2014). Amadori products generated from glucose and amino acids might contribute to animal's health because it has been reported that this compounds have several biological effects such as antioxidant (Ide et al, 1999), antihyperglycemia (Ha et al, 2011), and so on.…”

Discovery of Amadori‐Type Conjugates in a Peptide Maillard Reaction and Their Corresponding Influence on the Formation of Pyrazines

“…In addition, the formation of lysine-based, peptide-bound Heyns compounds has been clarified (Rene, Kathein, Evelyn, & Thomas, 2008). Recently, Troise et al (2015) analyzed Fru-Ala and Fru-Leu Heyns compounds via HPLC, and Meitinger et al carried out the investigation of Fru-Leu Heyns compounds in foods (Meitinger, Hartmann, & Schieberle, 2014;Troise, Fiore, Roviello, Monti, & Fogliano, 2015). This work is important in the characterization of fructose-based Heyns products of Maillard reactions and is helpful for the analysis of Amadori products of peptide-specific Maillard reactions.…”