Naslov
Effect of the tribomechanical micronization on the physical and thermophysical properties of whey proteins

Autori
Lelas, Vesna ; Herceg, Zoran

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Technology - Food - Nutrition - Health / Raspor, Peter ; Hočevar, Ivica - Ljubljana : Biotechnical Faculty, 2002

Skup
First Central European Congress on Food and Nutrition

Mjesto i datum
Ljubljana, Slovenija, 22.09.2003. - 25.09.2003

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
whey proteins; tribomechanical treatment; functional properties

Sažetak
In the equipment for tribomechanical micronization the intensive mechanical strains cause friction and collision among particles of hard mineral substances and the rupture of their crystal grates occurs. We believe that similar effects could be obtained using organic macromolecules such as whey proteins. Therefore our investigations were carried out with powdered whey protein concentrate as well as suspensions of these proteins before and after tribomechanical treatments. Whey proteins, because of their nutritive value and good digestibility are more and more used as a foood ingredient in various food products. They also have a very positibe effect on the human health and prevention of some diseases. Therefore, the knowledge of their physical as well as chemical and thermophysical properties is necessary for optimal designing of food processes. In this work the influence of tribomechanical treatment and some hydrocolloids addition on the phase transition temperatures of whey proteins suspensions were investigated. Powdered whey protein concentrate (WSPC) containing 60 or 80 % of proteins were tribomechanicaly treated at 22, 000 rpm. As a consequence, significant decrease of particle size and increawse of specific area as well as rupturing of molecule globules occurred. Protein suspensions containing 10 % of solid matter were prepared by mixing of powderer WPC before or after tribomechanical treatment, some hydrocolloids in amount of 0.4 % (guar gum, CMC, carageenan, DIKO, inulin, pectin, amid pectin) and water. Freezing and thawing temperatures were determined using differential thermal analysis (DTA). The results obtained have shown that the initial and end freezing temperatures are higher than the thawing temperatures of the investigated systems. Lower freezing temperautres (for cca 2oC) were determined in the systems prepared with tribomechanicaly treated proteins (TWPC) what indicates a significant lower moelcule weight of these proteins. The thawing temperatures of these systems were insignificantly lower than those of the systems prepared with untreated WPC. Hydrocolloid addition has effected tha decreasign of freezing temepratures of all investigated systems. The stronger effect had hydrocolloids based on CMC, and the most weakest effect had hydrocolloids type polysaccharides &#8211 ; inulin, pectin and amid pectin.

Izvorni jezik
Engleski

Znanstvena područja
Prehrambena tehnologija

POVEZANOST RADA