Comparative study of the emulsifying and foaming properties of defatted coriander (Coriandrum sativum) seed flour and protein concentrate

Emulsifying and foaming properties were determined for coriander protein pr oducts (defatted flour and protein concentrate) at pH 4.0, 7.0 and 9.0 and the results compared with those obtained for defatted soybean flour. Mean o il droplet size and interfacial protein concentration was smallest for emul sions (similar to 17% oil, v/v) stabilized by the coriander protein concent rate, when compared to the coriander and soybean flours. Polypeptide compos ition of the interfacial protein membrane of the emulsions was different fr om the polypeptide composition present in the respective coriander flour an d protein concentrate. In contrast, soybean flour-stabilized emulsions cont ained similar polypeptide composition to that of the flour. Soybean flour f ormed the greatest amount of foams at pH 4.0, 7.0 and 9.0 followed by the c oriander flour, which had greater amounts of foam at pH 4.0 and 5.0. The fo am stability of both the coriander flour and protein concentrate were signi ficantly (P less than or equal to0.05) less than those of the soybean flour . It was concluded that the reduced level of non-protein components in the coriander protein concentrate favoured increased surface activity at the oi l-water interface but not at the air-water interface. Crown Copyright, (C) 2001 Published by Elsevier Science Ltd. All rights reserved.