Processing of phosphocasein dispersions by dynamic high pressure: Effects on the dispersion physico-chemical characteristics and the binding of α-tocopherol acetate to casein micelles

Abstract : Dispersions of phosphocaseins (PCs) containing (w/w) 2.5% proteins at pH 6.7 were processed using a ~ 15 L/h homogeniser with a high-pressure valve immediately followed by cooling devices. The effect of dynamic high-pressure (or ultra-high pressure homogenisation, UHPH) at 100–300 MPa and two initial temperatures (Tin = 14 °C or 34 °C) was investigated on (i) casein micelle size distributions, (ii) the turbidity and viscosity of PC dispersions, and (iii) the binding efficiency of α-tocopherol acetate (α-TA) to casein micelles (α-TA:PC molar ratio ~ 1:1). A significant and gradual decrease of casein micelle sizes was observed after UHPH up to 300 MPa at Tin = 14 °C. The decrease in micelle sizes was less extensive after UHPH at Tin = 34 °C. Notably, the binding efficiency of α-TA significantly (p < 0.001) increased after processing, suggesting combined effects of temperature and dynamic high-pressure.Industrial relevanceIndustrial operators in food, cosmetic and pharmaceutical areas are currently interested in developing encapsulating systems to delivery bioactive compounds, generally hydrophobic, unstable and sensitive to light, temperature or/and oxygen. The present study suggests that processing of casein micelle dispersions by dynamic high pressure at ≥ 200 MPa could modify casein micelle organisation with an enhancement of the binding of hydrophobic ligand (α-tocopherol acetate) to the newly UHPH-formed neo-micelles. Here is a potential application for UHPH, a physical technology that offers the added advantage of notably reducing the microbial load of processed samples.Highlights► Native phosphocasein dispersions were processed by UHPH at two initial temperatures. ► Binding of α-tocopherol acetate to processed casein micelles was investigated. ► UHPH induced a significant and gradual decrease in casein micelle sizes. ► Binding of α-tocopherol acetate to casein micelles was enhanced after UHPH.
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https://hal.umontpellier.fr/hal-02059818
Contributeur : Laetitia Palmade <>
Soumis le : mercredi 6 mars 2019 - 21:43:57
Dernière modification le : vendredi 29 mars 2019 - 09:12:13

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Dominique Chevalier-Lucia, Claire Blayo, Alvar Gràcia-Julià, Laetitia Picart-Palmade, Éliane Dumay. Processing of phosphocasein dispersions by dynamic high pressure: Effects on the dispersion physico-chemical characteristics and the binding of α-tocopherol acetate to casein micelles. Innovative Food Science & Emerging Technologies, 2011, 12 (4), pp.416-425. ⟨10.1016/j.ifset.2011.07.007⟩. ⟨hal-02059818⟩

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