DETOXIFICATION OF THE JACKBEAN (CANAVALIA-ENSIFORMIS L.) WITH A PILOT-SCALE ROASTING - I - TECHNOLOGICAL CONDITIONS AND ANALYTICAL DATA

Experiments were conducted to investigate the relationships between va rious roasting conditions and the chemical composition of the jackbean samples. All data were analysed by using a Principal Component Analys is (P.C.A.) computerised programme. Whole jackbean was roasted on a pi lot scale coffee roaster. The temperature of the exhaust air and roast ing times were tested as operating variables. Nine trials were perform ed. The process variables were specific energy, and loss of mass measu red after cooling the seeds. Inactivation of the lectin (Concanavalin A) was monitored using a haemagglutination assay. In addition, urease activity, canavanine and cell wall contents measured according to the Van Soest procedure, were determined on each sample, Pilot scale roast ing of Canavalia appears to be feasible: specific energy consumption a nd loss of mass are well correlated with the duration of treatment (r= 0.93 and 0.84, respectively). Canavanine content is decreased with the specific energy (r=-0.89) whereas NDF was positively correlated (r=0, 75). Compared to unroasted jackbean, NDF was first lower, and then hig her with high energy consuming treatments. Haemagglutination activity of the 9 roasted samples disappeared completely. Both energy and produ ct transformations appear to be practically independent of roasting te mperatures in our experimental conditions. (C) 1998 Elsevier Science B .V.