Effects of extraction conditions on soluble oxalate content of the germinated paddy rice (Oryza sativa L.)
Duyen HH Nguyen, Ha VH Nguyen
In this study, effects of extraction conditions on soluble oxalate of paddy rice (Oryza sativa L.cv IR 4625) were analyzed using UHPLC chromatography. Extraction pH, sample-to-solvent ratios, extraction time and temperature were studied. The results showed that extraction in acidic condition (pH 3.0 – 6.0) led to a higher extracted soluble oxalate than other conditions (pH 7.0 and 8.0). The lowest soluble oxalate content was recorded at the 1:5 sample- solvent ratio (12.77 ± 0.07 mg/100g DW), while there were insignificant differences between other ratios. Moreover, the soluble oxalate content was insignificantly different at extraction temperatures and durations. The recorded data maybe useful for developing appropriate conditions for extraction of oxalate in paddies and may become databases for further study.