A novel organic acids-targeted colorimetric sensor array for the rapid discrimination of origins of Baijiu with three main aroma types

• Published in: Food chemistry 2024-07, Vol.447, p.138968-138968, Article 138968
• Main Authors: Wu, Meixia, Fan, Yao, Zhang, Jinbin, Chen, Hengye, Wang, Songtao, Shen, Caihong, Fu, Haiyan, She, Yuanbin
• Format: Article
• Language: English
• Subjects: Acids - analysis; Baijiu; Chlorophenols; Colorimetric reaction; Colorimetry; Gas Chromatography-Mass Spectrometry - methods; Odorants - analysis; Organic acids-targeted; Origin discrimination; Sensor array; Volatile Organic Compounds - analysis
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2024.138968

Given the severe problem of Baijiu authenticity, it is essential to discriminate Baijiu from different origins quickly and effectively. As organic acids (OAs) are the most dominant taste-imparting substances in Baijiu, we proposed a simple, fast, and effective OAs-targeted colorimetric sensor array based on the colorimetric reaction of 4-aminophenol (AP)/4-amino-3-chlorophenol (ACP) under oxidation of Cu(NO3)2 for the rapid discrimination of origins of Baijiu with three main aroma types. Hydrogen ions ionized from OAs induced the protonation of the amino group, which blocked the colorimetric reaction, and the different levels of OAs in Baijiu enabled the array to discriminate different origins of Baijiu. The array was implemented to analyze 10 simple OAs and 16 mixed OAs and further for the discrimination of 42 Baijius with an accuracy of 98%. This method provided an efficient research strategy for a basis for rapid quality analysis of Baijiu. [Display omitted] •A novel sensor array based on the colorimetric reaction was first proposed.•The colorimetric sensor array responded to organic acids specifically.•PSO-VWLS-SVM was used as a qualitative and quantitative analysis of mixed organic acids.•Different origins of Baijiu were discriminated by the colorimetric sensor array with an accuracy of 100%.