Effect of heat treatment on oxalate and hydrocyanic acid levels of malanga corms of two cultivars (Xanthosoma sagittifolium and Colocasia esculenta) in a murine model.

Xanthosoma sagittifolium and Colocasia esculenta contain high levels of nutrients; but have naturally toxic compounds, oxalates and hydrocyanic acid (HCN). The objective of this work was to evaluate the effect of heat treatment on the concentration of antinutrients in malanga corms and its effect on mice. Malanga samples were heated to a boil for 0 to 120 min; oxalates and HCN were determined by spectrophotometry, at 710 and 510 nm, respectively. Pellets were prepared from raw malanga flour (15 and 50%), cooked malanga (15 and 50%) and wheat flour (control) and fed for nine weeks to five groups of six mice each. Cooking of X. sagittifolium corms for 80 min reduced oxalates present by 75% (143 to 35.6 mg/100 g sample), while oxalates in C. esculenta were reduced by 83% (345 to 57.8 mg/100 g sample). HCN levels became negligible after 20 min of cooking. During the nine weeks of feeding the different mice groups showed no significant difference (p > 0.05) between initial and final weight, with respect of the control; mice did not lose their appetite. The results indicate that the consumption of cooked malanga does not pose an evident risk to health, assessed by the reduced level of antinutrients, being an excellent alternative for feeding people in communities with prevalence of food insecurity. © Association of Food Scientists & Technologists (India) 2021.