Preparation, characterisation and selected functional properties of hydrolysed sodium caseinate–maltodextrin conjugate

Authors

  • Jonathan O' Regan,

    Corresponding author
    • Department of Food and Nutritional Sciences, National University of Ireland Cork, University College Cork, Cork, Ireland
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  • Daniel M Mulvihill

    1. Department of Food and Nutritional Sciences, National University of Ireland Cork, University College Cork, Cork, Ireland
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Author for correspondence. E-mail: jonathant.oregan@gmail.com

Abstract

Sodium caseinate was hydrolysed to a limited, moderate or extensive degree. The hydrolysates were conjugated with maltodextrin by a Maillard-type reaction by dry-heat treatment at 60 °C and 79% relative humidity for 2 or 4 days. Conjugates were characterised by SDS–PAGE and gel permeation chromatography. In comparison with the hydrolysates themselves, the conjugated hydrolysates had improved solubility, particularly around the isoelectric pH of the protein. The emulsifying properties of these conjugates were assessed in oil-in-water (o/w) emulsions; on emulsion formation, each conjugate-stabilised emulsion had lower mean fat globule size than the corresponding hydrolysate-stabilised emulsion. After storage for 7 days under accelerated shelf life testing conditions, the limited and moderate hydrolysate conjugate–stabilised emulsions had improved storage stability compared with hydrolysate-stabilised emulsions; however, further research is required to optimise the hydrolysate fraction prior to conjugation for the production of novel low molecular weight emulsifiers.

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