59D-23 |
Characterization of soy proteins using spectroscopic technique |
K. A. KHATIB and T. J. Herald. Dept. of Animal Sciences & Industry, Kansas State Univ., Call Hall, Manhattan, KS 66506 Consumption of soy products has shown to be extremely beneficial for people who are concerned about heart disease and cancer. The beneficial effect is due mostly to soy protein and isoflavones. Soy protein quality could vary significantly among different soybean genotypes. In order to depict some of protein properties, new methods need to be developed. The objective of this research was to use spectroscopic analysis to differentiate between different soy genotypes grown under different environmental conditions. b-conglycinin and glycinin were prepared in each of the following three solvents: methanol, ethanol, and 1-butanol at a concentration of 1 x 10–6M and analyzed using a Spectra Flouromax equipped with a xenon arc lamp. Both emission and synchronous spectra were obtained after the sample was subjected to an excitation wavelength of the amino acid Tryptophan that is 280 nm. Results showed that the half width peaks corresponded to protein polarity that ranged from 1850 to 2370 nm, while peak height corresponded to rigidity, which ranged from 42 to 100 calculated unit. Maximum wavelength of the resulted peaks corresponded to polarity and was different among genotypes. Based on the data, we found that soy protein from different genotypes can be identified according to their quality (amino acids contents) and growing seasons. Subsequently, changes in hydrophobicity and hydrophilicity of soy proteins were found. Spectroscopic techniques can be useful to identify differences between samples of the same protein and proteins from different year crops and environmental conditions. By knowing the environment rigidity and polarity of soy proteins, food scientists could depict soy protein behavior. In addition, spectroscopic technique is convenient and fast method for characterizing soy proteins that can be correlated to the functional quality.
Session 59D, Food Chemistry: Proteins and Physicochemical Properties
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