Work

Organ-specific bioactivity and mineral profiles of Camellia sinensis across contrasting plantations in the Georgian Caucasus

Year: 2025

Type: article

Abstract: ABSTRACT Tea processing targets leaves, whereas fruit shells and seeds are typically discarded. This is the first regional study in the Georgian Caucasus, providing a comprehensive dataset from Georgian tea plantations. Using plantations from the Georgian Caucasus as a contrasting field setting, we assessed the mineral composition, polyphenols, antioxidant capacity, and carbohydrase-inhibitory activity of Camellia sinensis leaves, fruit shells, and seeds. We explored the co-variation between soil and plant. UPLC-MS/MS profiled polyphenols; minerals by ICP; antioxidant capacity by ABTS, DPPH, FRAP, and ORAC; α-amylase/α-glucosidase inhibition was expressed as IC₅₀. Leaves were catechin-rich (e.g., gallocatechin gallate up to 1140 mg/100 g dry matter (dm) and showed moderate antioxidant values, with the strongest α -amylase inhibition (IC₅₀ 6.10–8.60 mg/mL). Fruit shells, a processing by-product, exhibited the highest antioxidant capacity (e.g., FRAP 249–297; ORAC 315–344 μmol Trolox/g dm) and elevated Mn (167–223 mg/kg dm), yet no detectable carbohydrase inhibition. Seeds were enriched in apigenin C-glycosides (283–286 mg/100 g dm), presented the lowest IC₅₀ for α-glucosidase (1.92–2.25 mg/mL), and contained high K (0.80–1.25 g/100 g dm) with no detectable Pb, Al, Cd, or Ni. Multivariate analyses indicated a polyphenol–antioxidant axis and a K/Mg–enzyme association (co-variation, not causation). These findings reveal distinct, organ-specific functionalities and support zero-waste valorization, with fruit shells serving as antioxidant sources and seeds as candidates for modulating starch digestion. The results motivate replicated, multi-site work to disentangle the impact of soil versus management on scale extraction/utilization pathways for industrial applications. These findings provide the first regionally comprehensive insight into the functional and compositional diversity of Georgian tea plantations, supporting zero-waste valorization strategies and motivating replicated, multi-site studies to clarify environmental and management influences.

Source: Industrial Crops and Products

DOI: 10.1016/j.indcrop.2025.122222