Thesis Abstract

ABSTRACT The aim of this study was to investigate the effect of controlled fermentation using Aspergillus niger and Trichoderma harzianum on the nutrient composition of pre-treated Bengal indigo (Indigofera arrecta) seeds. Bengal indigo seeds were pre-treated to remove anti-nutritional factors and enhance digestibility. The pre-treated seeds were then subjected to controlled fermentation using Aspergillus niger and Trichoderma harzianum for a specified period under controlled conditions. The nutrient composition of the pre-treated seeds before and after fermentation was determined. Results showed that controlled fermentation led to a significant improvement in the nutrient composition of the Bengal indigo seeds. Protein content increased significantly, indicating the breakdown of complex protein structures into simpler forms that are more readily available for digestion and absorption. The increase in protein content could enhance the nutritional value of the seeds as a protein source. Furthermore, the levels of essential amino acids in the fermented Bengal indigo seeds were also evaluated. Results indicated an increase in the concentration of essential amino acids such as lysine, methionine, and tryptophan after controlled fermentation. These essential amino acids are important for overall growth and development in humans and animals. In addition to protein, the fermentation process also led to an increase in the levels of vitamins and minerals in the Bengal indigo seeds. Vitamin B complex, including thiamine, riboflavin, and niacin, showed a significant increase after fermentation. These vitamins play crucial roles in various metabolic processes in the body. Mineral content, including iron, zinc, and calcium, also increased after fermentation, potentially enhancing the seeds' nutritional value. Overall, controlled fermentation using Aspergillus niger and Trichoderma harzianum proved to be an effective method for improving the nutrient composition of pre-treated Bengal indigo seeds. The increased protein content, essential amino acids, vitamins, and minerals could contribute to the seeds' potential as a valuable nutritional supplement or feed ingredient for both humans and animals. Further research is warranted to explore the potential health benefits and practical applications of fermented Bengal indigo seeds in food and feed formulations.

Thesis Overview

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).