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

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 aspara-gine 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. Experi-mental and time costs associated with the analyses were estimated. The rapid test method had consistent ac-curacy, 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.