Naslov
Utjecaj tribomehaničke mikronizacije na reološka svojstva proteina sirutke
(Influence of Tribomechanical Micronisation on the Rheological Properties of Whey Proteins)

Autori
Herceg, Zoran ; Lelas, Vesna ; Škreblin, Mirjana

Izvornik
Food Technology and Biotechnology (1330-9862) 40 (2002), 2; 145-156

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, znanstveni rad, znanstveni

Ključne riječi
tribomechanical micronisation; rheological propeerties; hydrocolloids; whey protein concentrate
(tribomechanical micronisation; rheological properties; hydrocolloids; whey protein concentrate)

Sažetak
Investigations with powdered whey protein concentrates containig 60 % (WPC-60)and 80 % (WPC-80) of proteins were carried out. In this work proteins were treated using the laboratory equipment for tribomechanical micronisation with three different rotor speeds. Before and after tribomechanical treatment, the analysis of of the particle size and particle distribution as well as specific area and scanning microscopy were carried out. The influence of tribomechanical treatment as well as hydrocolloid addition on the rheological properties of model systems of whey protein concentrate (10 % total solid) was studied. Rheological parameters, flow behaviour index (n) and consistency coefficient (k) were determined by power-law model. The results obtained showed that the tribomechanical treatment involves a significant decrease in particle size, a change in particle distribution and an increase in specific area of powdered whey proteins. Systems without hydrocolloid addition were Newtonina, but those with hydorcolloid addition exhibited pseudoplastic properties. The viscosity of model systems containing tribomechanically treated whey protein concentrates (TWPC) was greater in comparison with the same systems prepared with untreated WPC. Systems with greater amount of proteins (WPC-80) had higher viscosity than the same systems containing lower amount of proteins. hydrocolloid addition affected an increase of viscosity of model systems prepared with untreated WPC. The most significant increase of consistency coefficient (k) was observed in systems with carboxymethylcellulose (CMC) and addition of a special type of carboxymethycellulose (CMC E466) known as DIKO, icecream binder 0911-E. In system contining tribomechanically tretaed TWPC hydrocolloids had various effects. In system with guar gum, carragenan, inulin, pectin or amid pectin, viscosity increased in comparasion with those prepared with untreated WPC. CMC and DIKO affected a significant viscosity decrease of TWPC model systems, which is the consequence of the interaction between proteins and (CMC) hydrocolloids. The found effects were pronounced more strongly as the rotor speed of TMA equipment was greater.

Izvorni jezik
Engleski

Znanstvena područja
Prehrambena tehnologija

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