Discrimination of wine age of Chinese rice wine by electronic tongue based on amino acid profiles

To ensure a good reputation for the producers and to guarantee the basic quality of wine for the consumers, an electronic tongue (E-tongue) coupled with a chemometric method was applied to rapidly discriminate the wine age of Chinese rice wine. Amino acid profiles analyzed by an amino acid analyzer together with principal component analysis (PCA) was used for validation of the wine age of the Chinese rice wine samples sourced from 1-year, 3-year, and 5-year. E-tongue responses collected by a potentiometric E-tongue together with discriminant analysis (DA) were used for the rapid discrimination of the wine age. The correlation between the E-tongue responses and the amino acid profiles was established by partial least squares regression (PLSR). The results showed that the calibration and validation samples were all correctly discriminated by the E-tongue coupled with DA. The E-tongue could be used for screening isoleucine (Ile), aspartic acid (Asp), tyrosine (Tyr), and valine (Val), with a residual predictive deviation (RPD) of greater than 2.0. The results indicated that using an E-tongue combined with DA was a reliable method for the discrimination of the wine age of Chinese rice wines.