Physical Properties of Oxidized Caffeic Acid Cross-Linked Whey Protein Films

Abstract

Abstract: Oxidized caffeic acid (OCA) was used to cross-link whey proteins for making cast films. The prepared films were analyzed for mechanical properties, water binding capacity, and protein solubility in Mc,Ilvaine buffer (pH 3 to 7) and the molecular weight of leached fractions. The results showed that the tensile strength, Young’s modulus and water binding capacity of films was markedly increased but its extensibility was not affected by the OCA incorporation. The degree of swelling significantly increased with increasing OCA concentrations. The protein solubility (leachability) of OCA-treated films slightly decreased at pH 3－5 but noticeably increased at pH 6 and 7 compared to untreated (control) films. Electrophoresis indicated that disulfide-linked proteins were the dominant components in leached fractions in pH 6 buffer solution.

Key words: oxidized caffeic acid, whey protein isolate, cross-linking, films, physical properties

References

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