Bambara groundnut (Vigna subterranea (L.) Verdc.) flour: A functional ingredient to favour the use of an unexploited sustainable protein source

Abstract

Variability in dehulling efficiency, colour, chemical composition and selected functional properties of raw and pre-treated bambara groundnut (Vigna subterranea (L.) Verdc.) (BG) flour from red and black-eye varieties were studied. Functional properties were water and oil absorption, gelation, pasting, emulsification and foaming capacity. Pre-treatment of seeds (i.e. soaking, roasting and combined soaking and roasting) improved dehulling efficiency of BG varieties. Protein content of flour ranged from 15.6–19.6%, starch from 47.8–52.0% and sucrose from 1.9–5%. An improvement was observed for protein and ash content of pre-treated flour compared to raw flour. Heat treatments increased onset gelatinization temperature of flour. Black-eye BG flours that had higher starch content, also had better gelation capacity than red BG flours. All pre-treatment methods decreased flour emulsification capacity and stability. Dry-roasting caused a greater decline than other methods, whereas soaking had little effect on emulsion stability. Further, soaking increased foaming capacity, whilst a decline was observed in roasted flour. All pre-treatment methods increased oil absorption capacity of both BG flour varieties. Overall, soaked and combined soaked and roasted flour is recommended for BG flour to be incorporated in food products.

Bambara Groundnut: An Underutilized Leguminous Crop for Global Food Security and Nutrition

“…The protein content of Bambara groundnut ranges from 9.6 to 40% ( 11 ), with an average value of 23.6% ( 9 ). This variation is also attributed to differences in genetic background, growing conditions, and analytical techniques used for estimation (e.g., nitrogen conversion factor) ( 10 , 35 ). Storage proteins are the predominant protein fractions in Bambara groundnut, of which vicilin (7S) is reported to be the major constituent, followed by legumin (11S) ( 38 ).…”

“…Dried Bambara groundnut can be ground into flour to improve its versatility ( 11 ). However, at the small scale, milling is laborious and time consuming due to a phenomenon described as “hard-to-mill” ( 10 ). The disruption of cell wall structure, through milling or other abrasive processing activity, can increase the availability and digestibility of nutrients, starch, and protein in particular ( 60 ).…”

“…Bambara groundnut contains ~64.4% carbohydrate, 23.6% protein, 6.5% fat, and 5.5% fiber and is rich in minerals ( 9 ). It is relatively underutilized compared with major cash crops and has often been associated with small-scale, subsistence farming, with women being the major producers and processors ( 6 , 10 ). The utilization constraints of Bambara groundnut include the knowledge gap in improved seed system, agronomic practices, processing, and utilization.…”

Correlation of the sensory attributes of thick yam paste ( amala ) and the functional and pasting properties of the flour as affected by storage periods and packaging materials

“…The trough viscosity measures the ability of the starch paste to withstand breakdown during cooling. Thus, the trough viscosity is very important in describing the quality of the starch gel (Adebowale et al, 2008;Adegunwa, Omolaja, Adebowale, & Bakare, 2016;Madsen & Christensen, 1996;Mubaiwa, Fogliano, Chidewe, & Linnemann, 2018 peratures and higher cooked paste stability when the yam flour is reconstituted in boiled water to amala (Farhat, Oguntona, & Neale, 1999;Rasper, 1969). (Table 5).…”

Evaluation of the Content of Polyphenols, Antioxidant Activity and Physicochemical Properties of Tortillas Added with Bambara Groundnut Flour

“…However, it is well known that all legumes including BGN are deficient in sulphur containing amino acids. Therefore, mixing BGN with a staple cereal grain such as maize is a desirable nutritional approach since maize has higher amounts of cysteine and methionine deficient in legumes [11]. Although BGN produces food with better nutrition, it is still one of the neglected crops in terms of research and development, becoming less important when compared to other well-known legumes and cereal crops and slowly losing its diversification and associated indigenous knowledge [12,13].…”