[en] The effects of pH (3.0, 6.0, 9.0) and heat treatment (25 °C, 65 °C, 95 °C) on the emulsifying properties of α−lactalbumin extracted from camel milk were investigated and compared to bovine α−lactalbumin. The results show that both studied proteins displayed a rather different evolution of their emulsifying activity as a function of the main factors (pH and temperature); however, they exhibited very close maximum values, between 100 and 110 m2 g−1. The stability of camel α−lactalbumin stabilised emulsions at pH 3.0 and 9.0 was attributed to the associated electrostatic forces (ζ−potential ~ −30 mV). The emulsifying properties of camel α−lactalbumin were less sensitive to heat treatment (95 °C), due to the higher conformational flexibility, as surface hydrophobicity increased with temperature (from 16 A.U to 51 A.U); conversely, bovine α−lactalbumin enhanced emulsion stability vs. pH and heat treatment, due to hydrophobic interactions and a more rigid molecular structure. Statistical tests also showed that the adsorption of camel α−lactalbumin at the oil−water interface was significantly affected by pH change.
Disciplines :
Food science
Author, co-author :
Ellouze, Maroua; Université Clermont Auvergne, CNRS, Sigma Clermont, Institut Pascal, Clermont-Ferrand, France ; Université de Sfax, Laboratoire d'Analyse, Valorisation et Sécurité des Aliments, Ecole Nationale d'Ingénieurs de Sfax, Sfax, Tunisia
MHESR - Ministère de l'Enseignement Supérieur et de la Recherche Scientifique
Funding text :
This project was financially supported by the higher education and scientific research ministry of Tunisia . Experiments were conducted at Institut Pascal (UMR CNRS-UCA-Sigma Clermont 6602), GePEB group in Clermont-Fd (France). The author wants to thank Dr. Roua Lajnaf and Dr. Ahmed Zouari for proofreading.This project was financially supported by the higher education and scientific research ministry of Tunisia. Experiments were conducted at Institut Pascal (UMR CNRS-UCA-Sigma Clermont 6602), GePEB group in Clermont-Fd (France). The author wants to thank Dr. Roua Lajnaf and Dr. Ahmed Zouari for proofreading.
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