Analysis of Geiasinization of Starch by Near Infrared Spectroscopy

Abstract

Possibility of near infrared (NIR) spectroscopy for analysis of changes in structure of starch due to gelatinization, and deteryination of degree of gelatinization was investigated. Among second derivative NIR specsra of rice starch samples having different degrees of gelatinization, largedeviations of spectra were observed at 1204, 1368, 1436, 1700, 1748, 1784, 1924, 2088, 2280, 2320 and 2348nm. Especially, specsra in the vicinity of 2100 and 2280nm changed complexly according to progress of gelatinizasion. As a result of linear regression using second derivative a bsorbance values of NIR specsra and degrees of gelatinizasion by BAP method, high correlations were obtained in the vicinity of 1807nm and 2095nm. In the vicinisy of l807nm, characseristic absorpsion band due to starch was notobserved. The parsicle size could be one of reasons why high correlation was obtained, because high correlation existed besween degree of gelatinization and particle size. In the vicinity of 2100nm, absorpsion due to starch and diffusion due to particle size overlapped. Then principal component (PC) analysis was applied to NIR spectra from 2040nm to 2144nm to reduce the effect of the diffusion on NIR spectra. Accurate linearity was obtained between second PC score and degree of gelatinization by BAP method. It was concluded that NIR specsroscopy has possibility to determine degree of gelatinization.