This study deals with drying properties and focuses on the drying kinetics of potato peels (PP) by two processes, namely convection drying (CD) at various temperatures (40, 60, 80, 100, and 120 °C) and microwave drying (MD) at different powers (200, 400, 600, and 800 W). In addition, the effectiveness of the adopted processes was evaluated in terms of antioxidant contents and antioxidant capacity. A total of 22 mathematical models were undertaken to predict the drying kinetics, and the best model was selected based on the highest R² values and the lowest χ² and RMSE values. The Sledz model was the more appropriate for both methods with values of 0.9995 ≤ R² ≤ 0.9999, χ² = 0.0000, and 0.0054 ≤ RMSE ≤ 0.0030 for CD, and the results of MD were 0.9829 ≤ R² ≤ 0.9997, 0.0000 ≤ χ² ≤ 0.0010, and 0.0304 ≤ RMSE ≤ 0.0053. The best drying rates (DR) of PP were assigned to a temperature of 120 °C and a power of 600 W with values of 0.05 and 0.20 kg water/kg dw min, respectively. A potential explanation is that as PP’s moisture content decreased during the drying process, there was a drop in absorption, which led to a reduction in the DR. The energy consumption of both processes was assessed, and it rose with increasing temperature or power. The microwave process reduced the drying time, consumed lower energy, and presented a higher drying efficiency at a moderate power level compared to the convection process. Furthermore, MD preserved antioxidants better compared to CD and improved the antioxidant capacity. Therefore, the proposed microwave process for drying PP is suggested for its expected use in various fields, including the food processing industries.

This work proposes the optimisation of the ultrasound assisted extraction (UAE) for total phenolic content (TPC) from potato peels (PP). The optimised extract was obtained using ethanol 20% (v/v) for 30 min at 40 °C, and it was found to be rich in total phenolics (45.03 ± 4.16 mg GAE/g DM) and flavonoids (7.52 EQ/g DM) and exerted a good antioxidant effect with IC_50s of 125.42 ± 2.78, 87.21 ± 7.72, and 200.77 ± 13.38 μg mL⁻¹ for DPPH, phosphomolybdate, and FRAP, respectively. PP were used for the fresh cheese formulation, and this supplementation did not impact its physicochemical properties; however, the phenol content and antioxidant capacity of formulated cheeses were improved. PP-enriched fresh cheese presented a good acceptability, even better than the control.

This investigation assessed the phenolic composition, and the in vitro and in silico antioxidant potential of peels from six potato varieties (Arizona, Spunta, Fabula, Manito, Argos, and Touareg) cultivated in Algeria. 80% ethanol was applied to macerate potato peels, and standard procedures were followed for phytochemical analyses. The in vitro antioxidant capacity was evaluated by the scavenging methods of DPPH (1,1-diphenyl-2-picrylhydrazil) and ABTS ((2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)) radicals. AutoDock Vina was employed to perform molecular docking analyses. LC–MS/MS analyses revealed significant variability in phenolic compounds among the varieties, with chlorogenic acid being the predominant compound, reaching the highest concentration in Touareg peels (51.28 µg/g). The Manito variety exhibited the highest total phenolic and flavonoids contents of 643.53 ± 2.59 mg GAE/100 g DW and 144.42 ± 2.40 mg QE/100 g DW, respectively and the strongest ABTS radical scavenging activity (IC₅₀ = 473.81 ± 1.35 µg/mL). Molecular docking analysis suggested potential interactions of catechin and chlorogenic acid with oxidative stress-related enzymes namely myeloperoxidase, xanthine oxidase, and 5-lipoxygenase, providing complementary insights into their possible biological relevance. The integration of in vitro and in silico results demonstrates that the Manito variety is the most promising candidate for the sustainable valorization of potato peels as a natural source of antioxidants.