Ultrafine Grinding a Promising Method for Improving the Total Dietary Fiber Content and Physico-Chemical Properties of Potato Peel Waste

Abstract

This study aims at determining the microstructure, particle size, composition ratio and physicochemical properties of ultrafine pulverized potato peel waste (PPW) obtained from expanded and unexpanded extrusion methods. Results obtained in our study show that ultrafine grinding processes significantly modify the structural properties of PPW by significantly reducing the size and distribution of particles in the prepared powder. We have extensively determined the total dietary fiber (TDF) content and hydration characteristics, cholesterol, sodium cholate and fat absorption capacities of the extruded PPW. Results show that with a uniform increase in the grinding time, total dietary fiber content (especially the total proportion of the soluble dietary fiber) and hydration characteristics including water retention and swelling capacity (SWC) of extruded PPW were found to increase significantly. We have also observed that ambient pH and liquids modified the structural properties of extruded PPW to varying degrees. Interestingly, we have observed no significant difference between the PPW samples extruded by expanded and unexpanded processes, which eliminated the redundant extrusion step before the ultrafine grinding process. Thus, ultrafine grinding is a time-efficient, cost-effective and user-friendly method for processing PPW. Results obtained in this study endorse the great potential of PPW in the food and beverage industries. Our future studies will be focused on understanding the influence of extruded PPW in enhancing the total dietary fiber content, food texture, storage and taste of various commercial food products.