Natural antioxidants from residual sources.

Antioxidative peptides from food proteins: a review

Hydrocolloids as emulsifiers and emulsion stabilizers

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The Merck Index

Food proteins and polysaccharides are the two key structural entities in food materials. Generally, interactions between proteins and polysaccharides in aqueous media can lead to one- or two-phase systems, the latter being generally observed. In some cases of protein-polysaccharide net attraction, mainly mediated through electrostatic interactions, complex coac-ervation or associative phase separation occurs, giving rise to the formation of protein-polysac-charide complexes. Physicochemical factors such as pH, ionic strength, ratio of protein to polysaccharide, polysaccharide and protein charge, and molecular weight affect the formation and stability of such complexes. Additionally, the temperature and mechanical factors (pressure, shearing rate, and time) have an influence on phase separation and time stability of the system. The protein-polysacchaide complexes exhibit better functional properties than that of the proteins and polysaccharides alone. This improvement could be attributed to the simultaneou...

Structure and Technofunctional Properties of Protein-Polysaccharide Complexes: A Review

To reduce the immunogenicity of β-lactoglobulin (β-LG), two β-LG−carboxymethyl dextran (CMD) conjugates (Conj. 40 and Conj. 162) were prepared by using water-soluble carbodiimide (EDC). The molar ratios of β-LG to CMD in Conj. 40 and Conj. 162 were 8:1 and 7:1, respectively. Each conjugate maintained ∼50% of the retinol binding activity of β-LG. Structural analyses by intrinsic fluorescence, CD spectra, and ELISA with monoclonal antibodies indicated that the surface of β-LG in each conjugate was covered by CMD without great disruption of native conformation. By conjugation with CMD, the antibody response to β-LG was reduced in BALB/c, C3H/He, and C57BL/6 mice, which was eminent in Conj. 162. The results of B cell epitope scanning using overlapping synthesized peptides showed that the linear epitope profiles of the conjugates were similar to those of β-LG, whereas the antibody response to each epitope was reduced, which was eminent in Conj. 162. It was concluded that conjugation with CMD of higher molecula...

Reduced Immunogenicity of β-Lactoglobulin by Conjugation with Carboxymethyl Dextran Differing in Molecular Weight

Two bovine β-lactoglobulin-carboxymethyl dextran (β-LG-CMD) conjugates (conjugates 10A and 10B) were prepared to improve the protein function by using water-soluble carbodiimide. The molar ratios of β-LG to CMD in the conjugates (Conj) were 7:2 (Conj 10A) and 1:1 (Conj 10B). The isoelectric point of each conjugate was 4.7-4.8, which is lower than that of β-LG. Spectroscopic studies suggested that the conformation around had not changed in either conjugate but the a-helix content of Conj 10A had markedly decreased as compared with that of β-LG. Structural analyses with monoclonal antibodies indicated the conformational change of 125Thr-135Lys (a-helix) in Conj 10A and of 15Val-29Ile (β-sheet) in Conj 10B

Functional changes in beta-lactoglobulin by conjugation with carboxymethyl dextran.

Insoluble elastin was rendered soluble by pepsin digestion and HCl treatment. The antioxidative activity of pepsin-solubilized elastin (PSE) and acid-solubilized elastin (ASE) was investigated. The...

Antioxidative Activity of Soluble Elastin Peptides

Bovine β-lactoglobulin−alginic acid oligosaccharide (β-LG−ALGO) conjugate was prepared by the Maillard reaction to improve the function of β-LG. The molar ratio of β-LG to ALGO in the conjugates was 1:7. The isoelectric point of the conjugate was 4.55, which is lower than that of β-LG. Fluorescence studies suggested that the conformation around Trp had changed in the conjugate and that the surface of the conjugate was covered with saccharide chain. Structural analyses with monoclonal antibodies indicated that the conformation around Val15−Ile29 (β-sheet) in the conjugate had changed, while native structure was maintained around Thr125−Lys135 (α-helix). By conjugation with ALGO, β-LG was endowed with high heat stability. The emulsifying activity and the aggregating property of β-LG was improved in the conjugate. Keywords: β-Lactoglobulin; alginic acid; alginate lyase; neoglycoconjugate; functional improvement; acidic polysaccharide; protein conjugation; emulsification; solubility; retinol-binding; lipocalin

Makoto Hattori

Papers

Reduced Immunogenicity of β-Lactoglobulin by Conjugation with Carboxymethyl Dextran Differing in Molecular Weight

Functional changes in beta-lactoglobulin by conjugation with carboxymethyl dextran.

Antioxidative Activity of Soluble Elastin Peptides

Functional Improvement of β-Lactoglobulin by Conjugating with Alginate Lyase-Lysate

Monoclonal antibodies as probes for monitoring the denaturation process of bovine β-lactoglobulin