A Review on the Cooking Attributes of African Yam Bean (Sphenostylis stenocarpa)

African yam bean, an underutilized legume usually cultivated for its edible tubers and seeds, is known for its nutrition-rich qualities; however, the crop’s level of consumption is low. The underutilization of the crop could be attributed to several constraints, including long cooking hours of up to 24 hours. Cooking time is an important food trait; it affects consumers’ choices, nutrients content, and anti-nutrient conditions. Additionally, foods requiring long cooking hours are non-economical in terms of energy usage and preparation time. The prolonged cooking time associated with AYB places enormous limitations on the invaluable food security potentials of the crop. Therefore, the availability of AYB grains with a short cooking time could lift the crop from its present underused status. To efficiently develop AYB grains with reduced cooking time, information on the crop’s cooking variables is a prerequisite. This review presents available information on variations in cooking time, cooking methods, and processing steps used in improving cooking time and nutrient qualities in AYB. Likewise, the review brings to knowledge standard procedures that could be explored in evaluating AYB’s cooking time. This document also emphasizes the molecular perspectives that could pilot the development of AYB cultivars with reduced cooking time.

Functional validation of Winged bean (Psophocarpus tetragonolobus (L.) DC.) anthocyanidin synthase (Wb ANS) gene through virus-induced gene silencing

Background Histochemical and microscopic observations of various tissues of the underutilized legume winged bean (Psophocarpus tetragonolobus (L.) DC.) indicated that the plant and its various parts are highly infested with condensed tannin (CT). Characterization of CT was carried out through the quantification of its structural-monomeric units catechin and epicatechin. The responsible candidate gene for anthocyanidin synthase (ANS) biosynthesis was identified, phylogenetically mapped and manipulated for lowering the CT-content. Results Virus-induced gene silencing (VIGS) was employed for silencing of WbANS transcript. WbANS-VIGS induction resulted in four-fold decrease in condensed tannin biosynthesis in P. tetragonolobus. Conclusion As condensed tannin adversely affects digestion and considered as an anti-nutrient, so this study might be helpful in future for altering the biosynthesis of condensed tannin by manipulating the ANS-encoding molecular factors.

Unraveling the regulatory role of miRNAs responsible for proanthocyanidin biosynthesis in the underutilized legume Psophocarpus tetragonolobus (L.) DC.

The underutilized legume winged bean (Psophocarpus tetragonolobus (L.) DC.) is deposited with various degrees of proanathocyanidin (PA) or condensed tannin (CT) on its seed-coat. PA content of two different lines of P. tetragonolobus was estimated and accordingly they were denoted as high-proanthocyanidin containing winged bean (HPW) and low-proanthocyanidin containing winged bean (LPW). The level of PA-content varied as 59.23 mg/g in HPW and 8.68 mg/g in LPW when estimated through vanillin-HCl assay. The identification and quantification of catechin and epigallocatechin gallate were estimated in a range of 63.8 mg/g and 2.3 mg/g respectively in HPW whereas only epigallocatechin gallate was reported in LPW line with a value of 3 mg/g. A comparative miRNA profiling of the leaf-tissues of these contrasting lines of P. tetragonolobus revealed a total of 139 mature miRNAs. Isoforms of known novel miRNAs were also identified in this study. Differentially expressed miRNAs e.g., miR156, miR396, miR4414b, miR4416c, miR894, miR2111 and miR5139 were validated through qRT-PCR analysis. Target prediction of the identified miRNAs especially miR156, miR396, miR4416b shows that they have a potential role in the proanthocyanidin biosynthesis of P. tetragonolobus. The study will provide the basis for understanding the role of miRNAs in regulating the biosynthesis of proanthocyanidin.

Nutritional, Antinutritional and Phenolic Properties of Lima Bean (Phaseolus lunatus) Accessions: Underutilized Legume in Ethiopia

The study was aimed to evaluate nutritional compositions, anti- nutritional factors and antioxidant properties of lima bean accessions grown in East Shoa Zone, Ethiopia. The lima bean accessions were studied and compared for their nutritional composition, anti-nutritional factors and antioxidant properties. The result showed that lima bean accessions were good source of vital nutrients when compared to the commonly consumed legumes in Ethiopia. Particularly, lima bean accessions “LB8510” rich in crude protein whereas accession “LB85CH2” rich in crude fiber, total ash and iron and can be implemented for breeding, new product development and used as alternative source of nutrient rich to mitigate malnutrition prevalent in Ethiopia. Therefore, increasing its consumption, cultivation and promotion should be encouraged.