Linear and non linear rheology and microstructure of emulsions containing carob protein as emulsifier

BENGOECHEA, C.; PUPPO, M.C.; CARMONA, J.; CORDOBÉS, F.; GUERRERO, A.

Hersonisos, Crete, Greece

Congreso; 3rd Annual European Rheology Conference; 2006

University of Crete - Hellenic Society of Rheology

Carob powder has been often used in western countries as a cocoa powder substitute in the food industry (Yousif & Alghzawi, 1999). The protein system present in the carob tree (Ceratonia siliqua), an evergreen Mediterranean plant, has been called caroubin by some authors (Wang et al., 2001; Feillet & Roulland, 1998) and it is a mixture of different proteins with a molecular weight range from more than one million to several thousands (Feillet & Roulland, 1998). Its potential as a food ingredient has been neglected for many years, though it could represent a cheaper competitor to other food proteins like dairy or soy proteins. This work focuses on the emulsifying properties of both carob meal (containing ~ 48% of protein) and carob protein isolate (~ 96%), which has been used to produce high concentrated oil in water emulsions (75% oil, 25% aqueous phase). The mechanical spectrum of these emulsions has been obtaining through oscillatory measurements carried out in a Control Stress rheometer (RS150, Haake, Germany), whilst an ARES rheometer (TA Instruments, USA) has been used to study the non linear properties. The microstructure of the emulsions has been studied by means of a Mastersizer X (Malvern Instruments, UK) and confocal microscopy (Leica, US).