Comparison of a rapid enzymatic assay with column chromatography and nuclear magnetic resonance methods for free asparagine detection and quantification in wheat

Abstract

A rapid, reliable, and user-friendly method that does not require complex sample preparation and sophisticated instrumentation will fulfill an emerging demand for free asparagine (ASN) analysis to ascertain acrylamide-related food safety issues in baked cereal products. This study validated a new method for wheat free asparagine analysis by comparing a rapid enzymatic test with two established analytical methods: UPLC and 1H-NMR using asparagine standards and whole-wheat flours with a range of free asparagine concentrations. For method validation, various quality parameters were assessed, including accuracy, precision, and sensitivity. Experimental and time costs associated with the analyses were estimated. The rapid test method had consistent accuracy, excellent precision of 1.0 or less (CV%), good sensitivity (0.0389 AU L mg−1) of free asparagine signal detection, and the least cost for experimental materials and instrument usage. A strong correlation (r = 0.997) between the results generated by the rapid enzymatic test and the UPLC method for free ASN quantification in whole-wheat flour was obtained. Overall, the rapid test method is recommended for ASN analysis in simple laboratory environments or in industrial applications.