Extraction of oxalate has been found to be problematic due its formation from precursors as well as variability in extraction
recovery. Exact determination of oxalate is highly important for the provision of dietary advice to subjects that are at a high
risk of kidney stone formation. Present study was proposed to optimize oxalate extraction conditions including acid type, time
and temperature. Cereal (wheat bran, barley bran and oat bran) and bean (red bean and white bean) samples were selected for
analysis. Hot (80°C) and cold acidic extraction (21°C) was performed with 15 and 30 min incubation times. Total and soluble
oxalate was analyzed by HPLC. Extraction of total and soluble oxalate increased at higher temperatures along with long
incubation times i.e. ranging from 576±5 to 73±1 mg/100g for total oxalate and 255±2 to 75±2 mg/100 g for soluble oxalate
respectively. This was attributed to generation of oxalate from its precursors at higher temperatures. Cold extraction with
shorter incubation time gave reproducible values along with good recovery in the range 279±4 to 71±2 mg/100 g for total
oxalate and 112±3 to 58±3 mg/100 g for soluble oxalate with recovery ranging from 95 to 99%.
Beenish Israr, Richard Andrew Frazier, Michael Hodson Gordon. (2019) OPTIMIZATION OF OXALATE EXTRACTION CONDITIONS APPLIED TO LEGUMINOUS AND CEREAL PRODUCTS USING HIGH PERFORMANCE LIQUID CHROMATOGRAPHY, , Volume 56, Issue 4.
