Rapid and Sensitive Analysis of Alkylresorcinols from Cereal Grains and Products Using HPLC−Coularray-Based Electrochemical Detection

Abstract

Alkylresorcinols (AR) present in the bran fraction of wheat, rye, and barley grains are of current interest as biomarkers of wholegrain cereal intake. This paper reports the development of a rapid quantitative HPLC method allowing sensitive analysis of AR in cereals in 14 min using coularray (CA) detection. The LOD was 1 ng injected and the LOQ 2.5 ng injected, whereas the intrarun and inter-run CVs were 0.8 and 6.4%, respectively. Analytical recovery determined by spiking ranged from 98 to 107% for AR homologues C15:0-C25:0. The method was used to analyze 79 flour and cereal products, with results in the same range as previous studies using GC analysis. Analysis of wholegrain white wheat were in the same range as other wheat varieties (420-556 microg/g). Use of the CA detector allowed detection of low concentrations of AR in white wheat flour (13-51 microg/g) that had not been reliably detected using previous methods. This method allows rapid throughput analysis of cereal samples, required for validation studies on the use of AR as biomarkers of wholegrain cereal intake.

Plasma alkylresorcinols as a biomarker of whole-grain food consumption in a large population: results from the WHOLEheart Intervention Study

“…AR in food samples used during the intervention were extracted by using hot 1-propanol (1) and analyzed by using HLPC with Coularray electrochemical detection (2). The variation with replicate analyses was ,4%.…”

“…4 are phenolic lipids found in high concentrations in the bran fraction of wheat and rye, in low concentrations in barley, and in only minute quantities in the endosperm (white flour) fraction of these cereals (1,2). ARs are mainly consumed via products containing WG wheat or rye or bran from these cereals.…”

“…Data were converted into grams of WG per day by using the American Association of Cereal Chemists definition of WG (22) and previously published information on the WG content of foods available in the United Kingdom (16). AR intake from foods or food groups containing WG or refined wheat or rye was estimated from analysis of the WG foods provided by using data available for specific foods (2) or estimates based on the average known flour content in each food or food group (15).…”

Effects of Energy and Macronutrient Intake on Cognitive Function Through the Lifespan

“…Recently, the HPLC method for the analysis of intact ARs in cereals using coularray detection (HPLC-CA) has been suggested. Use of the CA detector allowed detection of low concentrations of ARs in white wheat flour, which had not been reliably detected using previous methods (Ross and Kochhar, 2009).…”

“…The alkyl chain in cereal ARs varies from 15 to 27 carbon atoms. They are located in the intermediate layers between pericarp and testa in the grain (Landberg et al, 2008), and are found in high concentrations only in whole grain and/or bran products of wheat (31.7-143.9 mg/100 g dry matter, DM) and rye (36.0-320.0 mg/100g DM), and in very small amounts in refined flour (white bread, most breakfast cereals, pasta) or in any other commonly consumed foods (Ross et al, 2003;Ross et al, 2004a;Ross and Kochhar, 2009;Annica et al, 2010). They are also present in triticale (43.9-64.7 mg/100 g DM), and in small amounts in barley (4.2-5.1 mg/100 g DM), but not in oats (Ross et al, 2003).…”