Total Phenolic Content in Potato (Solanum tuberosum L.) Peel and Flesh Across Seed Generations

This study compared total phenolic content (TPC) in potato tubers of four Lithuanian cultivars (VB Venta, Goda, VB Meda, and VB Aista) across three seed propagation stages. Folin-Ciocalteu-reactive compounds were analyzed in peel, flesh, and whole-tuber samples from three seed propagation stages: minitubers (m₁), standard tubers (m₂), and first-class certified seed potatoes (E₁), using the Folin-Ciocalteu method. TPC was consistently highest in the peel, reaching 107.1 ± 5.3 µg gallic acid equivalents (GAE) g^-1 dry weight (DW) in VB Venta (m₂), whereas the highest flesh TPC (86.7 ± 4.3 µg GAE g^-1 DW) was observed in VB Meda (E₁). Across cultivars, peel TPC increased from 72.9 µg GAE g^-1 DW in m₁ to 85.6 µg GAE g^-1 DW in E₁. Whole-tuber TPC varied less among seed propagation stages (56.2-58.8 µg GAE g^-1 DW). Because the seed propagation stages were produced under different cultivation conditions, the observed differences cannot be attributed solely to seed generation. The results confirm the higher concentration of Folin-Ciocalteu-reactive compounds in potato peel and indicate its potential for further investigation as a source of bioactive compounds.