17E-19 |
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S. H. Jung, H.-A. LEE, C. J. Lee, S. J. Choi, and T. W. Moon. Department of Food Science and Technology, Seoul National University, School of Agricultural Biotechnology, San 56-1, Shillim-dong, Kwanak-gu, Seoul, 151-742, South Korea Proteins have unique surface and gel properties due to their large molecular weight and amphiphilic properties. Glycosylation of proteins with polysaccharides through controlled dry heating is an effective way to improve the functional properties of proteins, for example, solubility, emulsifying properties, gel properties, heat stability, and so on. Bovine serum albumin (BSA) processes various functionalities and dextran shows high viscosity. Therefore, we hybridized BSA and dextran to obtain conjugates with improved functionality. The objectives of this study were to investigate the binding pattern between BSA and dextran using multi-angle laser light scattering (MALLS) detector and to characterize their conjugate by measuring emulsifying properties and oscillatory viscoelasticity in a model system. BSA-dextran conjugates were prepared through Maillard reaction. The binding ratio of dextran to BSA was determined by a multi-angle laser light scattering detector. Structural analyses were carried out using fluorescence spectroscopy and circular dichroism. The covalent attachment of dextran to BSA was confirmed by SDS-PAGE. Up to 1 mole of dextran appeared to bind with 1 mole of BSA, resulting in the conjugate with maximum molar mass of around 660 kDa by MALLS data. Structural analyses indicated that the surface of BSA was covered by dextran without great disruption of native conformation. BSA-dextran conjugate showed excellent emulsifying properties by turbidimetric measurement. The stability of the conjugate emulsion prepared by sonication was 4 times better than that of the control native BSA. This might be due to covalently linked dextran. The result of dynamic oscillatory viscoelasticity of heat-set conjugate showed that BSA-dextran conjugate can improve the solid-like behavior of BSA gel. These results suggest that dextran, a neutral polysaccharide, decreasing the hydrophobicity of BSA by conjugation, could be utilized in protein-polysaccharide food systems for functional applications.
Session 17E, Food Chemistry: Proteins
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