Effect of Blanching Time on Physical, Colour and Rehydration Properties of Potato Flakes Dried by Convective Hot Air Drying

Convective hot air drying is extensively used for processing potatoes; nonetheless, the blanching conditions strongly influence the processing outcomes. This research examined the influence of blanching time (3, 4, and 5 minutes) on the physical, colour, structural, and rehydration attributes of potato flakes dried by convective hot air drying. The parameters assessed included bulk density, true density, porosity, moisture content, colour coordinates (L* and b*), and rehydration ratio. An increment in blanching time led to reduced bulk density and final moisture content; moreover, porosity was improved, implying more efficient diffusion of moisture during the convective hot air-drying process. Colour attributes were significantly impacted, and moderate blanching yielded enhanced brightness; nonetheless, apparent blanching led to deteriorated colour and heightened yellow chroma. The rehydration property was not linear, attributed to blanching-mediated changes in the structural attributes. The findings underscore the pivotal influence of blanching time on structure, mass transfer, and processing-quality relationships during convective hot air drying of potatoes. Therefore, blanching time optimisation is paramount for closing the efficiency-quality gaps.