Crack and cook: A simple and quick process for elimination of concanavalin A (Con A) from Canavalia seeds

The most nutritionally important antinutritional factor in the Canavalia seeds is Concanavalin A (Con A) which takes at least 3 h of cooking at 96°C to inactivate. The effect of breaking the seeds into smaller pieces before cooking on the Con A content was investigated. Whole seeds of Canavalia ensiformis (jackbean) and Canavalia ensiformis seeds that were broken into smaller pieces (3–7 parts per seed) were cooked at 96°C for 30, 60, 90 and 120 min, respectively. Some were cooked for 15, 30 and 45 min, respectively, under pressure using household pressure cooker. Con A content of the products was determined by the hemagglutination of rabbit fresh erythrocytes by the extracted protein samples serially diluted in PBS buffer in 96-microwell plates. Hemagglutinating activity was expressed as minimal concentration of protein inducing hemagglutination of cells. Hemagglutinating activity of the cracked beans was completely eliminated within 1 h of ordinary cooking and 15 min of pressure cooking. The cooked materials took 5–6 h of sunshine to dry to 90% dry matter. The hemagglutinating activity of the whole seeds was eliminated in 45 min of pressure cooking but not in 2 h of ordinary cooking. They took 3 days of same sunshine to dry. The crack and cook process (CAC), the name being proposed for the method, is commercially applicable in view of its relative ease of execution.