Effect of certain indigenous processing methods on the bioactive compounds of ten different wild type legume grains.

In recent years, research efforts are under-way on the possibilities of utilization of natural source of bioactive compounds for the dietary management of certain chronic diseases such as diabetes, obesity, cardiovascular diseases, cancer etc. In this connection, seed materials of promising wild type under-utilized food legume grains such as Acacia nilotica (L.) Willd. Ex Delile, Bauhinia purpurea L., Canavalia ensiformis (L.) DC., Cassia hirsuta L., Caesalpinia bonducella F., Erythrina indica L., Mucuna gigantea (Willd.) DC., Pongamia pinnata (L.) Pierre, Sebania sesban (L.) Merr. and Xylia xylocarpa Roxb. Taub., collected from South India, were investigated for certain bioactive compounds. All the samples were found to constitute a viable source of total free phenolics (3.12-6.69 g/100 g DM), tannins (1.10-4.41 g/100 g DM), L-Dopa (1.34-5.45 g/100 g DM) and phytic acid (0.98-3.14 g/100 g DM). In general, the seed materials of X. xylocarpa recorded high levels of total free phenolics and tannins, whereas the maximum levels of L-Dopa and phytic acid were noticed in M. gigantea and S. sesban, respectively. Further, presently investigated all the bioactive compounds were drastically reduced during soaking in tamarind solution + cooking as well as soaking in alkaline solution + cooking, and thus these treatments were considered to be more aggressive practices. Open-pan roasting also demonstrated a significant reduction of total free phenolics, tannins and moderate loss of L-Dopa and phytic acid. Alternatively, sprouting + oil-frying showed significant level of increase of total free phenolics (9-27%) and tannins (12-28%), but diminishing effect on phytic acid and L-Dopa. Hence, among the presently employed treatments, sprouting + oil-frying could be recommended as a suitable treatment for the versatile utilization of these wild under-utilized legume grains for the dietary management of certain chronic diseases.