Calcium oxalate reduction during soaking of giant taro (Alocasia macrorrhiza (L.) Schott) corm chips in sodium bicarbonate solution

The objective of this study was to investigate the effect of sodium bicarbonate concentration, time and temperature on the calcium oxalate reduction in giant taro (Alocasia macrorrhiza (L.) Schott) corm chips during treatment using sodium bicarbonate solution. Prior to the main study, a proximate analysis was carried out to obtain the chemical composition of taro tuber. To achieve that objective, giant taro corm chips were soaked in sodium bicarbonate solution with different concentrations, soaking times and temperatures, and the changes in calcium oxalate content was investigated. The proximate analysis of the giant taro corm showed that the corm is rich in carbohydrate, protein, minerals and fiber, but contains less fat. The changes in sodium bicarbonate concentration, soaking time and temperature led to significant (p ≤ 0.05) reductions in the calcium oxalate content. From the technical and economics considerations, the relatively good condition to reduce the calcium oxalate content is by soaking giant taro corm chips in 2% w/v sodium bicarbonate solution for 20 minutes at ambient temperature. That processing condition resulted final calcium oxalate content in the corm chips of about 67.67 mg/100 g or slightly below the threshold safe level, which is 71 mg/100 g.