Reducing the Soluble Oxalate and Phytic Acid in Taro Corm Chips by Soaking in Calcium Salt Solutions

Taro (Colocasia esculentum (L)) corm is one of the most nutritious and easily digested foods, but unfortunately contains anti-nutritional factors such as oxalates and phytic acid .The oxalates which can lead to risks of kidney stones, while phytic acid reduces bioavailability of minerals.Therefore, the anti-nutritional factors must be removed or decreased before utilization of corm as food by carrying out chemical or physical process such as soaking, boiling, fermentation or cooking.So, the incorporation of chemical and physical methods is expected to be a very efficient ways of processing.The aim of the present study was to investigate the effect of using calcium salts such as calcium carbonate, calcium chloride and calcium sulphate at different concentrations (0, 1, 3, 5 % w/v) during soaking periods for (30 and 60 min) on reducing soluble oxalate and phytic acid in taro corm chips.The experimental results indicated that the optimal conditions were soaking taro corm chips in calcium chloride solution at concentration of 5% for 60 min., since the content of both soluble oxalate and phytic acid were found to decrease from 294.3 to 35.1 mg/100g and from 161.16 to 133.68 mg/100g respectively.Calcium carbonate was the lowest effective additive.