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 Canaval ia seeds is Concanavalin A (Con A) which takes at least 3 h of cooking at 96 degrees C to inactivate. The effect of breaking the seeds into smaller pieces before cooking on the Con A content was investigated. W hole seeds of Canavalia ensiformis (jackbean) and Canavalin ensiformis seeds that were broken into smaller pieces (3-7 parts per seed) were cooked at 96 degrees 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 determine d by the hemagglutination of rabbit fresh erythrocytes by the extracte d protein samples serially diluted in PBS buffer in Bg-microwell plate s. 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 n ot in 2 h of ordinary cooking. They took 3 days of same sunshine to dr y. The crack and cook process (CAC), the name being proposed for the m ethod, is commercially applicable in view of its relative ease of exec ution. (C) 1998 Elsevier Science B.V.