Original scientific paper
Influence of tribomechanical micronization and hydrocolloids addition on enthalpy and apparent specific heat of whey protein model solutions
Zoran Herceg
; Prehrambeno-biotehnološki fakultet, Pierottijeva 6, 10000 Zagreb
Vesna Lelas
Suzana Rimac-Brnčić
Abstract
Knowledge of thermophysical properties, especially the phase transitions temperature, specific heat and enthalpy, are essential in defining the freezing process parameters as well as storage conditions of frozen food. In this work thermophysical properties of 10% model solutions prepared with 60% whey protein concentrate (WPC) with various hydrocolloids addition (HVEP, YO-EH, YO-L i YO-M) were investigated. Powdered whey protein concentrate was treated in equipment for tribomechanical micronization and activation at 40000 rpm (Patent: PCT/1B99/00757) just before model solutions preparation. Particle size analysis was performed using Frich –laser particle sizer “analysette 22”. The phase transition temperatures were determined by differential thermal analysis (DTA), while specific heat and enthalpy were calculated according to several mathematical equations. The results have shown that, due to tribomechanical treatment, certain changes in thermophysical and energetic properties of materials occurred. Tribomechanical treatment affects changes in granulometrical composition of WPC which result in higher abilities of reactions with hydrocolloids in model solutions and significant changes in thermophysical properties of the mentioned models.
Keywords
tribomechanical micronization; thermophysical properties; whey proteins concentrate; hydrocolloids
Hrčak ID:
1692
URI
Publication date:
16.1.2002.
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