Physicochemical properties of maltosyl and glucosaminyl derivatives of beta‐lactoglobulin

Abstract

Maltosyl and glucosaminyl derivatives of beta‐lactoglobulin (b‐LG) were analyzed for their physicochemical properties: reduced viscosity, ultraviolet difference spectra, intrinsic fluorescence, hydrophobicity and circular dichroism. The viscosity of these derivatives increased as the mass of the carbohydrates covalently linked to b‐LG increased. The ultraviolet difference spectra and the intrinsic fluorescence of these proteins revealed that the microenvironments of aromatic amino acid residues of b‐LG were increasingly exposed to the surface of the protein as the extent of modification increased; and the polarity of these residues also increased as modification increased. The hydrophobicities of M‐b‐LG derivatives decreased as the extent of modification increased while the hydrophobicities of G‐b‐LG derivatives were relatively unchanged. The circular dichroic analysis of these proteins indicated that the ordered secondary structures of the extensively modified derivatives of b‐LG were partially unfolded. Thus, the carbohydrates covalently linked to b‐LG altered many physiochemical properties. These physicochemical changes of b‐LG apparently resulted from an alteration of forces stabilizing the structure of the protein.

Antioxidative Ability of Chicken Myofibrillar Protein Developed by Glycosylation and Changes in the Solubility and Thermal Stability

“…This glycosylation method functionally alters food proteins, resulting in a marked resistance toward destroying the conformation and coagulation of ovalbumin, 2) changes in many physiochemical properties of -lactoglobulin, 3) solubilization of wheat gluten, 4) and the development of outstanding emulsifying properties in lysozymes.…”

Preparation of maltosyl, beta‐cyclodextrinyl, glucosaminyl, and glucosamineoctaosyl derivatives of beta‐lactoglobulin

“…reduced viscosity, ultraviolet difference spectra, intrinsic fluorescence, and circular dichroism, and functional, e.g. interfacial properties, solubility, foaming and emulsification, properties of the glycosylated derivatives of b-LG were conducted and will be reported in subsequent papers (14)(15)(16)(17).…”