Rheological properties of tribomehanically treated as well as untreated whey protein and starch

Na reološka svojstva hrane značajan utjecaj imaju brojni čimbenici od kojih su najvažniji temperatura, udio suhe tvari, kemijski sastav, pH i proces proizvodnje. Svrha ovog rada bila je ispitati utjecaj međudjelovanja tribomehanički tretiranih i netretiranih proteina sirutke sa škrobom na reološka svojstva modelnih sustava pripremljenih sa proteinima sirutke te dodatkom škroba. Reološki parametri ispitivanih suspenzija proteina određeni su upotrebom Ostwald de Waele-ovog zakona. Promjena viskoznosti ispitivanih suspenzija praćena je u temperaturnom intervalu od 10-60°C te je adekvatno opisana Arrhenius-ovom jednadžbom, budući da je koeficijent determinacije bio izrazito visok. Povišenjem temperature dolazi do kontinuiranog smanjenja viskoznosti kod svih ispitivanih sustava. Ispitivanjem reoloških svojstva utvrđeno je da sve proteinske suspenzije imaju nenewtonski karakter.Many factors, such as temperature, amount of dry compound, chemical composition, pH and production process have a significant influence on the rheological properties of food. The purpose of this work was to investigate the influence of temperature on the viscosity of model systems prepared with tribomehanically treated as well as untreated whey proteins and starch. Rheological properties of our suspensions were expressed by Ostwald de Waele’s model. Viscosity change of protein suspensions controlled between 10- 60°C, has been determined by Arrhenius’s equation, since the coeficient of the determination has been extremly high. The growth of temperature causes a continuous decrease of viscosity in every suspension we used. By examing rheological properties it has been estabilished that all proteins suspensions had non-Newtonian characteristics