Fermentation-based valorization of potato peel waste for the production of antioxidant fermentation-derived preparations by Lactiplantibacillus plantarum.

Agro-industrial byproducts represent an abundant yet underutilized resource for the production of value-added functional ingredients. In this study, potato peel waste was evaluated as a fermentation substrate for the production of antioxidant fermentation-derived preparations using Lactiplantibacillus plantarum ATCC 14917. Freeze-dried potato peel powder was characterized and used to prepare fermentation media with and without α-amylase supplementation. Fermentation was carried out for 96 h, and bacterial growth, pH, total phenolic content (TPC), and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity were monitored. L. plantarum exhibited successful growth in potato peel suspension, reaching approximately 7.9 log CFU/mL at 96 h, confirming the suitability of this substrate for lactic acid fermentation. Fermentation time significantly influenced both TPC (p < .001) and DPPH radical scavenging activity (p < .001). TPC increased from 332 to 484 mg GAE/100 mL at 48 h, then declined slightly thereafter. Similarly, antioxidant activity increased from 42% to 73% at 48 h. Although α-amylase supplementation promoted early microbial growth, it resulted in lower phenolic content and antioxidant activity compared to the non-supplemented medium. Overall, controlled fermentation of potato peel increased total phenolic content and antioxidant potential, demonstrating its promise as a sustainable substrate for the production of antioxidant fermentation-derived preparations.