Deoiling-Assisted Vacuum Frying of Potato Strips: Modelling and Optimization of Process Specifications

This study focused on the modeling and optimization of the deoiling-assisted vacuum frying process of potato strips. The process was compared with traditional frying in terms of posttreatment qualitative parameters including moisture loss, oil content, textural firmness, shrinkage, and total color difference. Effects of vacuum pressure (55–255 mmHg), oil temperature (95°C–155°C), frying duration (3–15 min), and deoiling duration in the cooling stage (0–100 s) on the quality parameters were evaluated. To model and optimize the vacuum frying process, response surface methodology via central composite design was used, and the corresponding models for each parameter were determined. The moisture loss and oil content increased significantly with an increase in the vacuum pressure, oil temperature, and frying duration (p < 0.05). Further surface oil adsorption into the product was prevented by increasing the deoiling duration. The firmness and shrinkage indicated a positive correlation with the oil temperature and frying duration. The optimal vacuum frying conditions were determined as 155 mmHg, 111°C, 6 min frying time, and 65 s deoiling duration, which led to a significant reduction in oil content and color deterioration compared to atmospheric frying (p < 0.05). An acceptable agreement was obtained between the experimental and predicted values (p < 0.05) confirming the model’s reliability. In conclusion, the optimized vacuum frying process with deoiling assistance effectively improved the quality of potato strips by reducing oil content and discoloration while maintaining desirable textural properties, demonstrating its potential as a healthier alternative to traditional frying. This was further demonstrated by sensory evaluation of apparent color, flavor, texture, and overall acceptance of the final product.