Thesis Abstract

Abstract
Fermentation is a traditional method used to improve the nutritional quality of various food materials by using specific microbial strains. In this study, the effect of controlled fermentation using Aspergillus niger and Trichoderma harzianum on the nutrient composition of pre-treated Bengal indigo (Indigofera arrecta) seeds was investigated. The pre-treatment of the seeds involved soaking and dehulling to remove anti-nutritional factors and improve digestibility. The controlled fermentation process was carried out under optimized conditions of temperature, pH, and incubation period. The nutrient composition of the pre-treated seeds was analyzed before and after fermentation, including proximate analysis, mineral content, amino acid profile, and anti-nutritional factors. The changes in nutrient composition were evaluated to determine the impact of fermentation on the seed's nutritional quality. The results showed that controlled fermentation using Aspergillus niger and Trichoderma harzianum significantly improved the nutrient composition of pre-treated Bengal indigo seeds. There was a notable increase in protein content, essential amino acids, and mineral content after fermentation. The reduction in anti-nutritional factors such as phytic acid and tannins indicated improved digestibility and bioavailability of nutrients. The study also revealed changes in the amino acid profile of the fermented seeds, with an increase in essential amino acids such as lysine, methionine, and tryptophan. These amino acids are essential for human health and are often limited in plant-based diets. The increase in mineral content, including calcium, iron, and zinc, further enhanced the nutritional value of the fermented seeds. Overall, controlled fermentation using Aspergillus niger and Trichoderma harzianum was found to be an effective method for improving the nutrient composition of pre-treated Bengal indigo seeds. The results suggest that fermented seeds could be a valuable source of protein, essential amino acids, and minerals for human consumption. Further research is needed to explore the potential applications of fermented Bengal indigo seeds in food products and their impact on human nutrition and health.

Thesis Overview

INTRODUCTION

The genus Indigofera Linn. is a large genus of about 700 species of flowering plants belonging to the sub-family Papilionoideae in the family Fabaceae / Leguminosae. They occur throughout the tropical and subtropical regions of the world. Burkill (1995) recognized 60 species while Soladoye and Lewis (2003) recorded 60 species in Nigeria with over 60% abundance in the Northern region of the country with 27 species distributed across the South Western area of the country. Indigofera in Greek means indigo dye which is famous for the natural blue colors obtained from the leaflets and branches of this herb. The most important of the species are Indigoferaarrecta and Indigofera tinctoria.

Indigofera spp. display excellent adaptation to a range of environments, and possessdiverse morphological and agronomic attributes, significant to their use as forage and cover crops (Hassen et al., 2006). Some of these species, Indigofera tinctoria and Indigofera suffruticosa are used to produced indigo dyes while some have medicinal values such as Indigofera articulate used for the treatment of toothache,

Indigofera oblongifolia, Indigofera suffruticosa and Indigofera aspalthoides are usedas anti–inflammatories for treatment of insect stings, snake bites and swellings (Shahjahan et al., 2005); and Indigofera arrecta extract is used to relieve ulcer pain.

The stem of Indigofera tinctoria is chewed to cure cough and decoction of leaves is used to cure chest pains, epilepsy, nervous disorders, asthma, bronchitis, fever and complaints of stomach, liver, kidney and spleen- especially in Cameroon (Takawira-Nyenya and Cardon, 2005). The twine paste cures dislocation. Also the warm leaves dismiss bruises (Ibe and Nwufo, 2005). Phytochemical investigation of Indigofera species shows that they are rich in organic and fatty acids, flavonoids such as carotenoids and coumarins (Yinusa et al., 2007).