Differentiation of Soy Sauce by Pattern Recognition Analysis of Mid- and Near-IR Spectra

✍ Scribed by Keiko Iizuka; Tetsuo Aishima

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 176 KB
• Volume: 12
• Category: Article
• ISSN: 0889-1575
• DOI: 10.1006/jfca.1999.0822

✦ Synopsis

For certi"cating the authenticity of soy sauce, mid-and near-IR spectra of 27 commercial soy sauce produced from whole soybeans and 30 from defatted soybeans were measured. Factor analysis applied to MIR and NIR spectra individually indicated the existence of some di!erence between two soy sauces. Then, SIMCA, conventional step-wise linear discriminant analysis (LDA) and LDA using genetic algorithms (GALDA) were applied to their spectra for classifying soy sauce samples according to types of soybeans. In step-wise LDA, 94.7% of samples were correctly assigned based on six wavenumbers in mid-IR spectra but 100% correct classi"cation was obtained by six wavelengths in NIR spectra. Cooman's plots in SIMCA applied to mid-or near-IR spectra indicated that di!erentiating two types of soy sauce samples was di$cult due to high similarity in their constituents. Perfectly correct classi"cation was attained by "ve to eight mid-IR wavenumbers and four to "ve near-IR wavelengths selected by GALDA. In general, the di!erentiation using NIR spectra was more reliable than that using MIR spectra.