Production of protein concentrate from shorts bran as a pasta industry by-product and investigation of some functional properties

In this study, two different shorts products (RZM-1 and RZM-2), which were pasta industry by-products, were used after removing crude oil content in the extraction of protein concentrates using distilled water or 0.15 M NaCI at pH 10, after lyophilisation, some functional properties of protein concentrates (PK-1S and PK-2S; PK-1T and PK-2T, respectively), like water holding and oil absorption capacity, protein solubility, emulsion capacity and stability, foam capacity and stability, were investigated. Protein contents of PK-1S, PK-2S, PK-1T and PK-2T were %79.1, %86.0, %82.3 and %86.7 on dry weight basis; yield values were %6.7, %5.6, %5.5 and %4.6, respectively. Colour properties of protein concentrates were similar to each other. The highest water holding and oil absorption capacities were obtained with PK-2S as 2.66 and 3.98 g/g, respectively. Functional properties were studied at 1.0% protein concentration as a function pH (pH 2-10). Protein solubility values of protein concentrates extracted using salt water (PK-1T and PK-2T) were generally higher than that of the protein concentrates extracted using distilled water (PK-1S and PK-2S). The highest protein solubility value (%81.8) was obtained with PK-1T at pH 2. The best emulsifying and foaming properties, which were seen at strong acidic and basic pH mediums, were depended on high protein solubility at these conditions. Protein solubility, emulsifying and foaming properties of all protein concentrates were the lowest at pH 6. Protein concentrates were used at different concentrations (%1.7-3.3) as egg replacer in the formulation of commercial cup cake (muffin cake). Densities of the cake batters prepared with 50% egg and protein concentrate supplemented increased relatively. The weight of cakes was close to control cake, but the height, volume, specific volume and cooking loss of cakes decreased while adding protein concentrate. The cake prepared wholly with PK-2S at 3.1% instead of egg had the highest moisture content (%24.6). Water activity values of the control and cakes prepared with egg replacers changed in the range of 0.80-0.85. The highest softness, moistness and crumbling (cohesiveness) points were provided with the cake sample prepared with 50% egg and 1.7% PK-1S protein concentrate. It was presented in this study that protein concentrates extracted from shorts can be used as egg replacer in cake formulations.