Ricebean

Abstract

Ricebean [Vigna umbellata (Thumb.), previously Phaseolus calcaratus] is a nonconventional and underutilized bean and an important crop for the generation of livelihood for poor rural and tribal farmers of South and Southeast Asia. Ricebean has a rich genetic diversity and high agricultural and nutritional potential in terms of being able to grow well in comparatively poor soils in hot and humid climates and resistance to storage pests and serious diseases. It is mainly grown as a crop in India, Philippines, China, Burma, Malaysia, Korea, Indonesia, Fiji, Sri Lanka, Mauritius, Sierra Leone, Ghana, Zaire, Tanganyika, Jamaica, Haiti, and Mexico and also to a limited extent in the West Indies, USA, Queensland (Australia), and East Africa. In India, it is cultivated mainly as a rainfed crop in the Northeastern Hills, West Bengal, Sikkim Hills, Western and Eastern Ghats Hills, Eastern peninsular tract (parts of Orissa), the Chhota-nagpur region in Western Himalaya in the Kumaon hills (U.P.), and in the Chamba region of Himachal Pradesh. Ricebean is also known as climbing mountain bean, mambi bean, oriental bean, and Beziamah in the Assamese language. Ricebean seeds have a smooth shiny surface, are slender to oblong in shape, 6-8 mm in length, 3-5 mm in width, 3-4 mm thick; rounded at both ends and with a concave, straight, or protruding hilum. The proportion of cotyledon, testa, and embryo in ricebean ranges from 88% to 90%, 7% to 9%, and 0.3% to 0.5%, respectively. Ricebean is a carbohydrate-rich grain with about 20% protein and low levels of fat content. It has high-quality protein with all essential amino acids in a balanced manner. The starch of ricebean has the lowest glycemic index (GI) compared to other beans such as mung bean, pea, pigeon pea, soybean, and cowpea. Ricebean has higher levels of potassium, calcium, iron, and zinc with better bioavailability for calcium and zinc. It is low in oligosaccharides (flatulence-producing saccharides such as raffinose, stachyose, verbascose, and ajugose) content than other pulses (Bepary andQ1 Wadikar, Journal of Food Science and Technology, 56(3): 1655-1662, 2019). The antinutritional factors such as trypsin inhibitor, α-amylase inhibitors, polyphenols, saponin, and phytic acid are greater, although tannin content is low as compared to other commonly consumed pulses. Food and nutritional security from ricebean can only be achieved if proper postharvest management, processing, and value additions are practiced. The postharvest management decides the quality and safety of ricebean grains and its products and the level of postharvest losses. This grain can be processed by using various technologies such as soaking, conventional cooking, microwave cooking, dehulling, germination, roasting, fermentation, extrusion, and flaking which improves the nutritional quality and safety. These processing techniques either alone or in combination can be utilized to develop several traditional as well as new ricebean-based products with higher nutritional quality, safety, and stability.