Soybean testa spectral study

Abstract

The increasing production volumes of soy foods require new express methods for testing soybeans during processing and presowing. This study assessed the efficiency of spectral pre-sowing assessment methods using Vilana soybeans. The research featured soybeans of the Vilana cultivar. The control sample consisted of untreated whole soybeans while the test samples included soybeans pretreated with various modifiers. The methods involved spectrofluorimetry and IR-Fourier spectrometry. A wide emission band at 400–550 nm corresponded to the fluorescence of the soybean testa. The band at 560–610 nm indicated the presence of such modifiers as Imidor insecticide and Deposit fungicide. The luminescence spectrum of the untreated soybean testa was maximal at 441 nm. The luminescence spectrum of the treated soybean samples was maximal at 446.5 and 585 nm when the excitation wavelength was 362 nm. The fluorescence was studied both spectrally and kinetically to establish the maximal luminescence time and the typical vibration frequencies. The spectral studies of Vilana soybeans before and after treatment revealed which modifiers were adsorbed on the palisade epidermis and defined the type of interaction between the modifier and the soybean. The spectrofluorimetry and IR spectroscopy proved able to provide a reliable qualitative and quantitative analysis of Vilana soybean surface.