Quality evaluation and optimization of potato drying methods are crucial in the food industry to ensure high-quality processed products. This research investigated the effect of four different drying methods: freeze drying (FD), infrared drying (ID), oven drying (OD), and infrared-assisted hot air drying (IR-HAD) on the post-processing quality of potatoes. Using non-destructive X-ray microtomography, the study analyzed the microstructural transformations of dried potato samples and was used to correlate these changes with quality attributes. The research introduced a new Hybrid Quality Score Evaluator (HQSE) to assess the Quality Index (QI) and Specific Energy Consumption Index (SECI) across various drying methods and durations. Firstly, the study investigated the impact of drying durations (4, 8, 12, and 16 h) on the quality of potatoes dried by FD, ID, and OD. Conventional quality assessment methods revealed significant (p < 0.05) variations in quality attributes such as colour retention, rehydration ratio, and total porosity. The developed mathematical models accurately predicted the QI and SECI. FD showed significantly higher (p< 0.05) colour retention, rehydration ratio, and total porosity, with minimal shrinkage, although it had higher energy consumption. In contrast, ID had the shortest drying time, followed by OD and FD. The optimization showed that the optimal time of 5.78 h for FD increased the QI by 9.7% and SECI by 30.6%. Based on these findings, the second objective of the research was focused on developing and validating a new IR-HAD system for quality enhancement of dried potato slices. The developed IR-HAD unit showed consistent drying conditions under three performance tests. The IR-HAD demonstrated superior drying kinetics, with a rapid decrease in moisture ratio and a significantly higher (p < 0.05) effective moisture diffusivity of 5.99 ×10^(-6) m^2 s^(-1) compared to other methods. Analyses of the HQSE demonstrated that IR-HAD excels in maintaining high-quality parameters within shorter drying durations and lower specific energy consumption compared to FD, ID, and OD. These findings are crucial for informed decisions in industrial applications, improving efficiency, quality, and energy savings.

Keywords: Potato, Freeze drying, Infrared drying, Oven drying, Infrared-assisted hot air dryer, X-ray microtomography, Quality and Energy Consumption Indexes.