Comparison of water blanching and high hydrostatic pressure effects on drying kinetics and quality of potato

Drying kinetics and quality parameters of potato cubes were evaluated as affected by high pressure processing and hot water blanching. The potato cubes in 1% citric acid solution as immersion medium were pressure treated at 400 MPa for 15min. Hot water blanching was conducted in boiling water for 3min. Drying kinetics and quality parameters (i.e., rehydrability, texture, color and apparent density) were assessed for the high pressure-treated and water-blanched samples and for dehydrated and rehydrated samples. Drying rates were found to be higher (p < 0.05) in the initial period of drying for the presssure treated samples. The Page model was found to better fit drying data o the thermally treated samples, and the two-terms model better described the drying behavior of high pressure-treated samples. Hgh pressure treated samples had a similar rehydrability to thermally treated samples. It was found that pressure treated samples had a hardness value to that of fresh samples, whereas thermal treatment resulted in a sfter texture. After rehydration, smples of both treatments returned this texture before drying. The total color difference for the thermally blanched samples was higher (p < 0.05) than or pressure-treated samples before drying and after drying. High pressure and dried potato cubes had a color close to that of fresh potato cubes. High-pressure-treated and air-dried samples were found to have higher (p, < 0.05) apparent density than thermally treated samples.