Specific Standardization and Determination of Curcuminoid Levels in Turmeric (Curcuma longa) Rhizomes from Three Cultivation Centers in Java Using the HPLC Method

Curcuma longa is one of Indonesia's most important medicinal plants, with curcuminoids (curcumin, demethoxycurcumin, and bisdemethoxycurcumin) responsible for its anti-inflammatory, antioxidant, hepatoprotective, and anticancer activities. This study aimed to standardize turmeric rhizomes from Temanggung, Blitar, and Wonogiri and determine curcuminoid levels using a validated HPLC method. Specific standardization parameters were evaluated according to the Indonesian Herbal Pharmacopoeia (FHI) Edition II, while HPLC analysis employed a C18 reversed phase column with UV detection at 425 nm. All samples met FHI physicochemical standards, and the HPLC method showed excellent linearity (r² ≥ 0.9996), precision (%RSD ≤ 0.95%), and accuracy (98.7–99.8%). Curcuminoid content differed significantly among cultivation sites (p < 0.001), with the highest level in Blitar (4.48 ± 0.09%), followed by Temanggung (3.96 ± 0.07%) and Wonogiri (3.39 ± 0.06%). Curcumin levels ranged from 2.46–3.19% w/w, exceeding the FHI minimum standard (≥1.0%). These findings demonstrate that cultivation site significantly influences curcuminoid profiles, emphasizing the importance of region specific quality specifications for herbal raw material procurement.