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
Xiushi Yang, Bao Xing, Yuqing Guo, Siyu Wang, Huimin Guo, Peiyou Qin, Chunsheng Hou, Guixing Ren
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.