DisplayTitle

Finding inexpensive and sustainable protein sources is crucial to feeding a growing world population. POET has developed a cost effective process to extract zein from the ethanol process. The zein product is light in color making it easy to use in foods. Extruded products are popular but their low protein content is a concern for health conscious consumers. Producing high-protein extrudates can be challenging. Adding protein typically reduces expansion, increases product hardness and density making it less enjoyable for consumers. Previous work showed that zein behaved differently from other proteins. It increased expansion and decreased product hardness and density. It was hypothesized that zein could be used to improve the quality attributes of high-protein extrudates. A recipe for a 25% soy protein isolate (SPI) extrudate was modified to include 5, 10 or 15% zein. The blends were extruded using an experimental extruder using the optimum extrusion conditions for a 25% SPI extrudate. The zein/SPI extrudates were characterized. The expansion ratio increased linearly with the zein content. The addition of 5, 10 and 15% zein increased the expansion by 9.4, 13.7, and 19.2% respectively. It decreased the product hardness by 15.1, 18.2, and 36.5% respectively. The addition of 5% zein decreased the bulk density by 31% and the increased the product crispiness by 36%. The extrusion conditions were further optimized for the zein/SPI blends. Optimizing the extrusion condition had the greatest effect on the expansion ratio. The addition of 5, 10 or 15% zein increased expansion by 19.9, 34.3, and 57.6% respectively. The addition of zein increased crispiness and decreased product hardness and density. The results suggest that zein can be used a texture modifier and could be used to produce high-protein products such as breakfast cereals and snacks.