Novel colorimetric sensor array for identification of baijiu using color reactions of flavor compounds

Abstract

The flavor of baijiu, a type of distilled spirit, mainly depends on the presence of certain flavor compounds. In this study, we focus on the four most important groups of flavor compounds in baijiu, viz. aldehydes, ketones, esters, and acids. Simple organic reactions, including the hydroxylamine color reaction, 2,4-dinitrophenylhydrazine (DNPH) nucleophilic addition reaction, and localized surface plasmon resonance (LSPR), exhibited by noble metal nanoparticles were used to construct an eight-channel visual array sensor, which can be used to directly and qualitatively detect the four major groups of flavor compounds in consideration. Using the optimized variable-weighted least-squares support vector machine, based on the particle swarm optimization (PSO-OVWLS-SVM) model, the sensor array allowed good quantification. The results of this study were supported by principal component analysis (PCA) and hierarchical cluster analysis (HCA) techniques. The results suggested that the sensor array can be used for the rapid detection of flavor compounds in actual baijiu samples.