Phytate dodecasodium salt hydrate

Phytate content, as myo‐inositol hexakisphosphate, was analyzed using high‐performance ion chromatography (HPIC) following the method described by Carlsson et al.25 and modified by Lazarte et al.5 Duplicate samples of 0.5 g were extracted with 20 mL of 0.5 mol L^–1 HCl for 2 h at room temperature under constant stirring. Supernatant was recovered after centrifugation (Model Allegra® X‐15r, Beckman Coulter, Brea, CA, USA) at 2851 g for 10 min at 20 °C. Supernatant was frozen overnight, thawed, and centrifuged (Model Optima™ LE‐80 k, Beckman Coulter Brea, CA, USA) at 12348 g for 10 min at 20 °C. Supernatant (2 mL) was filtered through a 0.2 μm syringe filter disk and 50 μL of supernatant were injected and analyzed by HPIC with an OmniPac PA‐100 (4 × 250 mm) analytical column and a PA‐100 (4 × 50 mm) guard column (Dionex Corp., Sunnyvale, CA, USA). Detection and quantification of phytate were made after a post‐column reaction with 0.1 g L⁻¹ Fe(NO₃)₃.9H₂O (99.99% trace metal basis) (Sigma‐Aldrich) in 20 g L⁻¹ HClO₄; the absorbance was monitored at 290 nm in a UV detector (Waters 486, tunable absorbance detector, Waters Corporation, Milford, MA, USA). Phytate dodecasodium salt hydrate (Sigma‐Aldrich, Staad, Switzerland) was used as standard. The limit of detection of the method was 0.13 g kg⁻¹.