The extracts were analyzed in duplicate for oxalate by using a commercially available enzymatic kit (Trinity
Biotech, Berkeley Heights, New Jersey), which is based on measuring the amount of hydrogen peroxide
liberated from the oxidation of oxalate by oxalate oxidase. Oxalate concentrations are expressed in mg/100 g of
dry herbal sample weight and mg/100 g of fresh fruit weight (± standard deviation of two separate extractions).
min. The supernatant was transferred to a 25-ml volumetric flask and the remaining oxalate in the pellet was
extracted two additional times. The final volume of the collected supernatant from the 3 successive extractions
was diluted to 25 ml with distilled deionized water. The extracts were kept frozen until the time of oxalate
analysis. Each sample was extracted in duplicate.