Enhancing CO2 puffing drying of potatoes through ethanol and freeze-thaw post-treatment

CO₂ expansion puffing drying (CO₂-EPD) is a low-temperature high-pressure puffing drying technology that can produce fruit and vegetable crisps with a crispy texture and high nutritional retention. This study compared the effects of no treatment, ethanol osmosis dehydration pre-treatment (EOD), freeze-thaw treatment (FT), and ethanol osmosis dehydration followed by freeze-thaw treatment (EOD + FT) on the texture and nutritional quality of potato slices by CO₂-EPD. The results showed that potato slices treated with the EOD + FT pre-treatment method achieved a puffing degree of 2.02, hardness of 782.52 g, crispness of 687.47 g, protein content of 2.63 g/100 g, vitamin C content of 16.74 mg/100 g, and a color difference (ΔE) of 2.08. This pre-treatment method significantly improved the overall quality of the potato slices. Further investigation into the effects of freezing temperature, freezing time, ethanol concentration, and ethanol soaking time on the texture and nutritional quality of potato slices was conducted. EOD + FT pre-treatment enabled effective puffing at lower temperatures, thereby enhancing the overall quality of potato slices. The EOD + FT + CO₂-EPD technology is an efficient drying process that significantly improves the texture and nutritional quality of potato slices, providing valuable theoretical references and practical guidance for the production, processing, and quality analysis of potato slices.