Feasibility of Near Infrared Diffuse Reflectance Method for Determination of the Quality of Dried Laver(Porphyra yezoensis)

Abstract

This study was conducted in order to ascertain a feasibility of near infrared diffuse reflectance method that might be applied to determine the quality grade of dried laver('Nori')in place of seasory evaluation by specialized inspectors. Results obtained were as follows: (1)The higher the quality was, the stronger the absorbance was obtained in all of the wavelength region of 1.1 to 2.5 μm. The variation of absorbance among different grade of the quality showed more distinctly in a longer wavelength region of near infrared. (2)There was a tendency that the absorbance around 2.0 to 2.2μm of wavelength region showed less intensity for a higher grade of the quality. (3)A single linear regression ana1ysis was made between the grade of the quality and absorbance at about 35 bands obtained in the spectrum using an original log(1/R), the first derivative dlog(1/R)or the second derivative d²log(1/R)spectra. According to the correlation coefficients at the wavelengths of 2.056, 2.110 and 2.168μm, especial1y, it was suggested that the higher the grade of the quality was, the more protein content was and by contraries the less carbohydrate content was. (4)On the other hand, the reu1ts of multiple linear regression analysis showed that near infrared diffuse reflectance method had a high capability to determine the grade of the quality of dried laver relating to a chemical composition provided the second derivative spectra might be used.