The influence of extrusion process with a minimal addition of corn meal on selected properties of fruit pomaces

摘要

The aim of this study was to investigate the influence of the extrusion process on nutritional composition, anthocyanin content, as well as sorption, and the other physical characteristics of cherry and black currant pomaces. Physical properties (expansion ratio, bulk density, and water absorption solubility index) were evaluated. The equilibrium moisture content values as a function of the water activity were determined as sorption isotherms by three mathematical models. The effect of extrusion on the chemical composition and anthocyanin content was analyzed. It was found that the extrusion process increased water solubility index and decreased anthocyanin and dietary fiber content values. All obtained isotherms showed sigmoid shape. In both fruit pomaces, equilibrium moisture content values were lower in extrudates than in the raw pomaces. Obtained results can be used in order to find new possible applications of the main by-product from the juice pressing process. Presented results can also be useful in: creating and optimizing quality of new food products, determining their stability during storage, and extending shelf life. Practical applications The obtained results proved the great potential of the extrusion process as one of the options for managing fruit waste. They indicate that it is possible to utilize by-products obtained in the fruit processing process on industrial scale. The presented results can also be used in the design of new food products using fruit pomace as a source of nutrients.