Hazelnut and Walnut Oil Cakes as Health‐Promoting Ingredients of Extruded Corn Snacks

ABSTRACT The aim of the study was to develop a recipe for innovative and health‐promoting extruded corn products enriched with powdered hazelnut or walnut oil cakes and to assess their quality. Nut oil cake is a by‐product of the food industry, created during oil pressing. Corn semolina was replaced with nut oil cakes at the level of 10%, 20%, and 30%. The content of basic nutrients, the expansion ratio ( ER ), the color in the CIEL* a * b * space, the content of total polyphenols (TPC), antioxidant potential (AA), textural properties were determined, and an analysis of the smell was carried out using an electronic nose. It was found that replacing corn semolina with nut oil cakes increased the content of protein, dietary fiber, and ash in the tested extrudates, and the content of these components increased with their increasing share. Similarly, an increase in TPC and AA was observed in extrudates containing nut oil cakes. The highest ER values were observed in samples with 10% and 20% of walnut oil cakes. The hardest were extrudates with 30% of hazelnut oil cakes. Nut oil cakes caused a decrease in the L * parameter value, that is, a significant darkening of the extrudates compared to the control sample. The analysis of the smell allowed us to identify in the extrudates odorous substances belonging to five groups, such as aldehydes, alcohols, ketones, pyrazines, and terpenoids. The conducted studies showed the possibility of using by‐products from the food industry, such as nut oil cakes, in the production of innovative corn extrudates with interesting functional properties and improved nutritional value.