Potato processing by-products in the food industry as a rich source of bioactive compounds

Potato is one of the four most important crops worldwide, following rice, wheat, and maize. Approximately 50% of global potato production is processed into products such as chips, French fries, and starch (Vescovo et al., 2025). Large-scale potato processing generates significant amounts of waste, paritcularly potato peel, which accounts for approximately 10% of the total processed material. Although commonly discarded, potato peel represents a valuable and highly available source of bioactive compounds. The main objective of this study was to investigate the effects of different ethanol concentrations (20, 40, 60, 80, 96%) on the total polyphenol content and antioxidant activity of potato peel extracts obtaned by conventional solid-liquid (S/L) extraction. Antioxidant activity was evaluated using DPPH, FRAP, and ABTS assays.

The total polyphenol content ranged from 1.28 to 3.89 mg GAE/g DW. Antioxidant acticity determined by the DPPH assay ranged from 2.17 to 3.96 mg TE/g DW, while FRAP values ranged from 0.78 to 2.40 mg Fe²⁺/g DW. ABTS values ranged from 4.35 to 11.46 mg TE/g DW. The highest extraction efficiency and antioxidant activity were achieved using 40% and 60% ethanol, indicating that moderately polar solvents are the most suitable for the extraction of polyphenolic compounds. The obtained results demonstrate that potato peel is a rich source of polyphenols with significant antioxidant activity. Considering that potato peel is an abudant food processing by-product, its valorization could contribute to waste reduction and enable the production of valuable extracts and bioactive compounds for applications in the food, pharmaceutical, and cosmetic industries.

Reference:

1. Vescovo, D., Manetti, C., Ruggieri, R., Spizzirri, U. G., Aiello, F., Martuscelli, M., & Restuccia, D. (2025). The valorization of potato peels as a functional ingredient in the food industry: A comprehensive review. Foods, 14(8), 1333.