Rapid, accurate and simply-operated determination of laboratory-made adulteration of quinoa flour with rice flour and wheat flour by headspace gas chromatography-ion mobility spectrometry

Abstract

The growing consumption of quinoa flour has triggered an elevating concern about its adulteration with similar but cheaper cereals. Herein, a headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) method was applied for the authentication of laboratory-made quinoa flour adulteration with wheat and rice flours. A total of 81 volatile compounds were detected from the 28 samples. Principal component analysis (PCA), cluster analysis (CA), and orthogonal partial least square discriminant analysis (OPLS-DA) were used to distinguish pure from adulterated samples. Authentic and adulterated quinoa flours using different proportions (5, 10, 20, 40, and 80%, w/w) were easily classified based on their volatile profiles. More importantly, n-hexanol, 3-methyl-1-butanol, (E)-2-hexenal, butyrolactone, 1,8-cineole, alpha-phellandrene, 2-propanone, and 2-hexanone were proposed to be volatile markers for quinoa flour authentication from the adulterants. The HS-GC-IMS based determination of volatiles was confirmed to be an effective method for adulteration detection of quinoa flour.