Study of Acetylated Food Proteins by Raman Spectroscopy |
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| Authors: | Y Z HAO C Y MA S N YUEN D L PHILLIPS |
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| Affiliation: | Authors Zhao, Ma, and Yuen are with the Dept. of Botany, Univ. of Hong Kong, Pokfulam Rd., Hong Kong. Author Phillips is with Dept. of Chemistry, Univ. of Hong Kong, Pokfulam Rd., Hong Kong. Authors Ma and Phillips are with Centre for Applied Spectroscopy and Analytical Sciences, Univ. of Hong Kong. Direct inquiries to author Ma (E-mail: macy@hkucc.hku.hk). |
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| Abstract: | ABSTRACT: Three food proteins, soy protein isolates, spray-dried egg white, and whey protein isolates, were acetylated to varying levels, and the extent of modification was determined by wet chemistry methods. Raman spectra of the modified proteins were obtained. A new C=O stretching vibration was observed at 1737cm-1 and was attributed to ester carbonyl groups appended to the proteins during acetylation. Calibration curves were obtained by plotting the intensity ratio of this Raman band to the 1003cm-1 phenylalanine stretching band against the extent of substituted hydroxyl groups. Linear fits were obtained with correlation coefficient r > 0.9979. The Raman spectral data were also analyzed to study the effect of acetylation on the conformation of the 3 proteins. Marked conformational changes were observed in the modified proteins. |
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| Keywords: | acetylation proteins soy protein isolates egg white whey protein isolates Raman spectroscopy |
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