Differentiation of the Aroma Quality of Soy Sauce by Statistical Evaluation of Gas Chromatographic Profiles

Stepwise discriminant analysis (SDA) and principal component analysis (PCA) were applied to quantitative gas chromatographic (CC) profiles of soy sauce volatiles in order to compare soy sauce quality evaluated by sensory evaluation with GC data. Although the brands of soy sauce were roughly separated into four groups on the basis of canonical score with the same tendency of the sensory rank, SDA correctly classified each sample into the proper group of the 8 groups. The six PCs among 8 factors extracted from the selected 39 peaks by the PCA showed significant relationships with the sensory evaluation in multiple regression analysis. The first PC showed a 55% of contributing proportion. The importance of harmonious balance of each aroma compound for the aroma quality was evident from a comparison of the six PCs.