Ekstruzija je jedan od najznačajnijih procesa u prehrambenoj industriji gdje se vrlo često kao osnovna sirovina koristi kukuruzna krupica. Zbog poboljšanja fizikalno-kemijskih svojstava i nutritivne vrijednosti, u kukuruznu krupicu se mogu dodavati brašna različitih žitarica. Cilj ovog istraživanja bio je ispitati utjecaj dodatka zobi na svojstva ekstrudiranih proizvoda na bazi kukuruzne krupice (omjeri kukuruzna krupica Specijal : zob = 80 : 20 i kukuruzna krupica Resli : zob = 80 : 20). Dobivenim ekstrudatima ispitana su fizikalna, termofizikalna i reološka svojstva u odnosu na neekstrudirane uzorke. Istraživanjem je utvrđeno da je dodatkom zobi došlo do smanjenja ekspanzijskog omjera i povećanja nasipne mase, kao i povećanja tvrdoće i smanjenja lomljivosti ekstrudata. Ekstruzija je uzrokovala posvjetljenje kod kukuruzne krupice Specijal, a potamnjivanje kod kukuruzne krupice Resli. Dodatkom zobi došlo je do potamnjivanja uzoraka obje vrste kukuruznih krupica te smanjenja zasićenosti boje. Ekstruzijom se povećao indeks apsorpcije (WAI) i indeks topljivosti u vodi (WSI), te je došlo do značajnog oštećenja škroba kod svih uzoraka, s time što je dodatkom zobi u oba slučaja smanjena oštećenost škroba. Postupkom ekstruzije i dodatkom zobi došlo je do smanjenja viskoznosti vrha, viskoznosti pri 92 °C i viskoznosti pri 50 °C kod svih uzoraka te su ekstrudirani uzorci bili manje skloni retrogradaciji.

Extrusion is one of the most significant processes in food industry, where corn grits is often used as main raw material. In order to increase nutritive value and improve physical and chemical properties, flours of different grains are added to corn grits. The aim of this research was to determine the influence of oat flour addition on properties of extruded products based on corn grits (ratio corn grits Specijal : oat = 80 : 20 and corn grits Resli : oat = 80 : 20). The physical, thermophysical and rheological properties of extrudates were compared to non-extruded samples. Results showed that addition of oat resulted in decrease of the expansion ratio and fracturability of extrudate and increase of bulk density and hardness. Extrusion resulted in increase of brightness of corn grits Specijal, and decrease of brightness of corn grits Resli. The mixing of oat with corn grits resulted in decrease of brightness of both Specijal and Resli samples and reduction of color saturation. Extrusion also resulted in the increase of water absorption (WAI) and water solubility index (WSI), as well as the significant starch damage in all samples. In both cases addition of oat resulted in reduced starch damage. Peak viscosity, viscosities at 92 °C and at 50 °C were decreased after extrusion and with addition of oat in all samples and all extruded samples were less prone to retrogradation.