PL
Celem pracy było zbadanie wpływu dodatku mokrego młóta browarnianego na parametry jakościowe ekstrudatów kukurydzianych. Do badań zastosowano dwuślimakowy ekstruder laboratoryjny współbieżny Evolum 25 firmy Clextral z matrycą o średnicy dyszy wylotowej 4 mm. Uzyskane próbki ekstrudatu poddano analizie i oznaczono: gęstość (D), wskaźnik ekspansji radialnej (REI), wskaźniki wodochłonności (WAI) oraz rozpuszczalności w wodzie (WSI), aktywność wody (WA) oraz zawartość białka w produktach (PC). Stwierdzono, że zmiany parametrów procesu ekstruzji oraz zastosowane proporcje mieszanek kaszki kukurydzianej i młóta browarnianego miały istotny wpływ na zmiany parametrów jakościowych uzyskanych ekstrudatów. Zwiększenie udziału młóta w mieszance powodowało poprawę własności ekstrudatów, o czym świadczyły wzrost wskaźnika WAI i obniżenie wskaźnika WSI oraz wzrost zawartości białka.
EN
The aim of the study was to investigate influence of wet brewer’s spent grain addition and process condition on the selected physical parameters of corn extrudates. The extrusion trials were performed with Clextral Evolum 25, co-rotating twinscrew extruder. The extruder was fitted with a circular die with a diameter of 4 mm. The ingredients used for extrudates preparation were: corn grid (12% moisture content) and wet brewery spent grain (WBSG) with 78% moisture. The extruded mixtures were prepared with 0%, 5%, 10%, 20% addition of WBSG. The fresh WBSG was received from Brewery in Łomża. The extrusion conditions were: feed rate of 5 kg·h–1, mixture moisture: 13, 16, 19,5, 26%, screw speed of 200, 250, 300 rpm, respectively. The barrel temperature profile were as: 60°C at feed entry, 80, 110, 110°C at the middle sections and 110°C at the die exit. During each experiment response parameters were constant. The extrudates which leaved the die were cut on approx. 3 cm long pieces and left to cool at room temperature to moisture stability (13%) until analyzed. One of the advantages of WBSG adding is that we can reduce energy consumption used to drying WBSG without quality loses. The quality of corn-brewery spent grain (BSG) extrudates were estimated by some parameters: density (D), radical expansion index (REI), water solubility index (WAI), water activity (WA) and protein content (PC). The results indicated that the density of extrudates increased with the increase of BSG content in the mixture and reached the highest value at 20% proportion BSG. Although the speed of extruder screws had a statistically significant effect on this parameter, changes were minor. Increasing the BSG level to 20%, increased the WAI value up to 600%, and decrease WSI index 4 times, from 40% down to 10%. It is not without significance for the growth of WAI seems the fiber contained in BSG influence. The fiber is able to store water inside of the extrudate particles. Fiber caused a reduction of starch degradation, which further with the increase insoluble fiber contain in the extrudate meant that the WSI value was decreased. Changes in the extrusion process parameters have also influences on changes other qualitative indicators, which are water activity and protein content of the extrudates. It was found that the water activity significantly increased with the increase in the BSG proportion in the mixture, while the impact of the extruder screws speed was low.