Oil-free potato chips produced by microwave multiflash drying

The present work is about the production of oil-free potato snacks using successive cycles of microwave heating-vacuum pulses and was therefore called microwave multiflash drying (MWMFD). Drying kinetics and product physical properties were assessed, as well as the influence of blanching (BL) and vacuum impregnation (VI) as pre-treatments before drying. The drying curves presented three periods: a heating period, a high drying rate period promoted by the vacuum pulses, and a falling rate period. The drying time of 400 g of potatoes was approximately 60 min, reducing gradually the microwave power from 800 to 200 W. The vacuum-pulse step changed the material, resulting in a porous and fragile microstructure, characteristic of crispy products, as well resulting in a product surface with a golden yellow color. BL and VI combined was the best pre-treatment for obtaining very crispy oil-free potato snacks. The results of this study indicated MWMFD as a suitable process to produce crispy potato snacks, free of oil, in only 60 min.