Purpose

Bambara groundnut is a hard-to-cook grain and this has limited its utilisation to some extent. However, the grain is a good source of phytochemicals with antioxidant properties. This study investigated the total phenol content, antioxidant, anti-inflammatory and anti-microbial potentials of hot-water extract of four Bambara groundnuts differentiated by their seed coats (cream, black, maroon and brown).

Design/methodology/approach

Bambara grains were heated in water at a ratio 1:20 (w/v) and the grains brought to boiling in a controlled water bath. As soon as boiling started, the temperature was reduced to 90 °C to reduce the evaporation rate. The extracts were withdrawn within 30 min, which was chosen from a preliminary study where beyond this time, the extract was drying off and the amount of solution obtained was not sufficient for the initial run. Grain colour and composition and antioxidant, antimicrobial and anti-inflammatory properties of the extract were determined using standard methods.

Findings

Protein (20.57–26.31%) and carbohydrate (55.43–61.09%) were the major components of the grain. Grain type and boiling time generally affected the total phenolic content of the extract. Cream Bambara displayed substantially lower total phenolic content at all boiling times compared with the maroon, brown and black Bambara groundnuts. The total flavonoid contents and total phenolic contents of the Bambara groundnut extracts were dependent on the boiling time and type of grain. The extracts showed no activity against Candida albicans, but the maroon coat Bambara demonstrated a peak inhibition of 6.00 mm against Escherichia coli. The total phenolic, flavonoid contents and the antioxidant properties of the grains generally followed the order Maroon > Black > Brown.

Originality/value

This study has demonstrated the possibility of promoting the use of Bambara groundnut beyond the current level of usage by using simple processing method of boiling to extract phytochemicals with medicinal properties.

中文翻译：

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班巴拉花生（Vigna subterranea L.）种子提取物的总酚含量，抗氧化剂，抗炎和抗菌潜能

目的

班巴拉花生是难以煮熟的谷物，这在一定程度上限制了其利用率。但是，谷物是具有抗氧化特性的植物化学物质的良好来源。这项研究调查了四种班巴拉花生的热水提取物的总酚含量，抗氧化剂，抗炎和抗菌潜力，这些花生通过种皮（乳脂，黑色，栗色和棕色）加以区分。

设计/方法/方法

将班巴拉谷物在水中以1:20（w / v）的比例加热，并将谷物在受控的水浴中煮沸。沸腾一开始，温度就降低到90°C，以降低蒸发速率。在30分钟内撤回提取物，该提取物是从初步研究中选择的，超过此时间，提取物将被干燥，所获得的溶液量不足以进行初始运行。使用标准方法测定提取物的谷物颜色和组成以及抗氧化剂，抗微生物和抗炎特性。

发现

蛋白质（20.57–26.31％）和碳水化合物（55.43–61.09％）是谷物的主要成分。谷物类型和煮沸时间通常会影响提取物的总酚含量。与栗色，棕色和黑色的班巴拉花生相比，奶油班巴拉在所有沸腾时间均显示出较低的总酚含量。班巴拉花生提取物的总黄酮含量和总酚含量取决于煮沸时间和谷物类型。提取物对白念珠菌没有活性，但栗色的班巴拉（Bambara）表现出对大肠杆菌的峰值抑制作用为6.00 mm 。谷物的总酚，类黄酮含量和抗氧化性能通常遵循栗色>黑色>棕色的顺序。

创意/价值

这项研究表明，通过使用简单的煮沸方法提取具有药用特性的植物化学物质，有可能促进班巴拉花生的使用超出当前的使用水平。