Introduction to food, feed, and health wealth in African yam bean, a locked-in African indigenous tuberous legume

Abstract

The African yam bean, Sphenostylis stenocarpa Hochst Ex. A. Richmond, Harms, is an indigenous tuberous legume of the humid tropics of Africa. Its edible pulse and tuber host significant promises for food, nutrition, and health security. It was identified as a counterpart of cowpea in the 1970s and rated to be highly nutritious, but notable constraints have denied it research and funding attention. “Cowpea revolution” further deprived focus on the African yam bean. However, some research updated and promoted its significant food, feed, and nutritional-pharmaceutical values between 1973 and 2000. The global trend for food diversification has further improved awareness and research on the African yam bean this past decade, but research focus on the tuber is incomparably small. The abundant minerals, vitamins, and bioactive compounds in the two economic products unveiled in the present review assure food, health, and nutritional security. The analytical comparison of nutritional values of the African yam beans and other grain legumes demonstrated the significant place of the crop among its counterparts. Furthermore, investigative research identified the grain as a good substitute for soybean for livestock feed formulations. Although no clinical study has been reported, some in vivo, in vitro, and ex vivo biological activities and human studies of the two economic products revealed their efficacy in the management of anti-natal lactation induction, anemia, diabetes, arthritis, etc. However, African yam bean still suffer displacement in rank, utilization, and popularity compared to the “favored” legumes. While the present review adds to its advocacy, awareness, and utilization, a coordinated research program that will boost its value chain is most necessary for progress.

Chromosome-scale assembly of the African yam bean genome

“…African yam bean (hereafter referred to as AYB) is important for food and nutritional security in local communities in sub-saharan Africa. AYB is a rich source of dietary protein with up to 30% and 10% protein content in the seeds and tubers, respectively 3,4 . Its seeds and tubers are also low in fat and rich in carbohydrates, minerals and vitamins 3,4 .…”

“…AYB, however, is largely underutilised due to the hardness of the seed coat, leading to long cooking time and the presence of anti-nutritional factors which reduce protein digestibility 3 . Also, the need for staking of plants has greatly hampered its cultivation on a commercial scale.…”

Morphological, pathological and phylogenetic analyses identify a diverse group ofColletotrichumspp. causing leaf, pod, and flower diseases on the orphan legume African yam bean

“…However, AYB is underutilized. African yam bean produces two organs of economic importance, grains, and tubers, although not all AYB accessions produce tubers (Adewale and Nnamani 2022). African yam bean is consumed based on regional preferences and beliefs.…”

Nutritional, functional, and bioactive properties of african underutilized legumes

“…Tuberous underutilized legumes are gradually gaining recognition. These include the African yam bean (AYB) (Sphenostylis stenocarpa) cultivated in West Africa for the seeds and in East and Central Africa for the tubers (Adewale and Nnamani, 2022); winged bean (Psophocarpus tetragonolobus), grown and cultivated in Papua New Guinea Highland, northern Ghana, and Burma; the Marama bean (Tylosema esculentum) cultivated in the Southern Africa regions of Botswana, Namibia, Mozambique, Zambia, and in northern South Africa (Abberton et al, 2020a;Abberton et al, 2020b;Ojuederie et al, 2021;Sriwichai et al, 2021); Mexican yam bean (Pachyrhizus erosus); Zombi pea (Vigna vexillata) an underutilized legume with a pantropical distribution; hyacinth bean (Lablab purpureus) grown in North Africa; as well as Tala (Neoapaloxylon tuberosum) cultivated in Madagascar (Von Wettberg et al, 2021). Different tuber shapes and sizes of some tuberous underutilized legumes are presented in Figure 1.…”