Changes in some nutritional components of Vigna racemosa as influenced by hydrothermal processing techniques

M.A Ojo,B.I.O Ade-Omowaye

doi:10.26656/fr.2017.6(1).664

Abstract

Vigna racemosa is an underutilised hard-to-cook legume in Southwest Nigeria. The seed of V. racemosa was subjected to varying degrees of hydration levels (0%, 10%, 25%, 50% 75% and 100%) before treatment with four hydrothermal techniques, atmospheric boiling, atmospheric steaming, pressure boiling and pressure steaming. The highest percentage reduction of 65.56% in cooking time was achieved at a 100% hydration level when the seeds were processed by boiling at elevated pressure. All the hydrothermal techniques had a significant effect (p<0.05) on the protein content of the seeds. Hydration of the seeds to 100% followed by boiling at elevated pressure caused the least reduction in the protein and mineral element contents. The seed is a good source of important nutrients that are not degraded beyond the levels necessary to meet physiological needs after processing. Widening the scope of utilisation of this legume seed will make critically important nutrients such as protein more available for the teeming populations in developing countries at affordable prices, and thus, alleviating the problem of protein-energy malnutrition (PEM).

Highlights

Vigna racemosa is an underutilised hard-to-cook legume in Southwest Nigeria
The curve gives the indication of hydration levels attainable for the legume seeds over twenty-four hours
The highest percentage reduction in cooking times was recorded at 100% hydration level when the seeds were boiled at elevated pressure

Summary

Introduction

Vigna racemosa is an underutilised hard-to-cook legume in Southwest Nigeria. The seed of V. racemosa was subjected to varying degrees of hydration levels (0%, 10%, 25%, 50% 75% and 100%) before treatment with four hydrothermal techniques, atmospheric boiling, atmospheric steaming, pressure boiling and pressure steaming. Widening the scope of utilisation of this legume seed will make critically important nutrients such as protein more available for the teeming populations in developing countries at affordable prices, and alleviating the problem of protein-energy malnutrition (PEM). Legumes contain antinutritional factors such as tannin, saponin, heamaglutinin, cyanogenic glycoside, phytic acid etc These antinutritional components must be inactivated and/ or reduced if their value is to be realised because they interfere with normal digestive processes and prevent efficient utilisation of nutrients (Reddy and Sathe, 2002; Sathya and Siddhuraju, 2015; Ojo et al, 2018). Some of these underutilised legumes are hard-to-cook (Ojo et al, 2017a). The future thrust of this work is on the use of V. racemosa for the preparation of local dishes such as moinmoin (steamed cake), gbegiri (bean soup) and akara (fried cake): it is believed that widening the scope of its utilisation will create dietary diversity and healthy eating habits

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Results

Conclusion