Thesis Abstract

Abstract
Breadfruit (Artocarpus altilis) is a staple food crop in many tropical regions, known for its starchy fruit that is commonly consumed in various forms. This study aimed to evaluate the physicochemical properties of African breadfruit starch concentrate obtained through a novel extraction process. The research involved assessing the proximate composition, pasting properties, thermal properties, and morphological characteristics of the starch concentrate. The proximate analysis revealed that the African breadfruit starch concentrate had a moisture content of 10.5%, protein content of 0.8%, fat content of 0.2%, ash content of 0.5%, and carbohydrate content of 88.0%. The pasting properties of the starch concentrate were determined using a Rapid Visco Analyzer (RVA), showing values for peak viscosity (4198 cP), trough (3670 cP), breakdown (528 cP), final viscosity (4848 cP), setback (648 cP), and peak time (7.3 min). Thermal analysis using differential scanning calorimetry (DSC) indicated an onset gelatinization temperature of 66.5°C, peak gelatinization temperature of 73.2°C, conclusion gelatinization temperature of 79.8°C, and gelatinization enthalpy of 9.6 J/g for the African breadfruit starch concentrate. Scanning electron microscopy (SEM) images revealed a granular structure with irregular shapes and sizes, typical of starch granules. Overall, the physicochemical properties of the African breadfruit starch concentrate demonstrated its potential for various food and non-food applications. The composition analysis indicated a high carbohydrate content, which is desirable for a starchy ingredient. The pasting properties suggested good thickening and gelling capabilities, making it suitable for food formulations. The thermal properties highlighted the gelatinization behavior of the starch concentrate, which is crucial for processing applications. The morphological characteristics observed through SEM provided insights into the structural properties of the starch granules, which can influence functionalities such as swelling capacity and interaction with other ingredients in food systems. This comprehensive evaluation of the physicochemical properties enhances the understanding of African breadfruit starch concentrate and opens up opportunities for its utilization in industries such as food, pharmaceuticals, and materials science. Further research can explore optimization of extraction processes and functional properties to fully exploit the potential of this underutilized starch source.

Thesis Overview

1.0   INTRODUCTION

African breadfruit (Treculia africana) constitutes a strategic reserve of essential food nutrients that are available at certain critical periods of the year when reliable sources of these nutrients are under cultivation and are very scarce. Diverse food forms could be produced from the seeds on the basis of custom, tradition, ethnic background. It is boiled and consumed as white porridge and sauce with or without fresh corn, roasted and consumed with coconut or palm kernel as snack, made into refreshing milk drink, prepared into flour as soup condiment or thickener and for bakery and confectionaries. In the past the consumption was limited to poor village dwellers for whom it supplemented their diets during times of food scarcity and substituted the more expensive rice during festivals and other ceremonies on the basis of tradition and cost (Nwabueze and Nwokenna, 2006). But today, African breadfruit has become a delicacy and a specialized meal not only for the rich and the urban dwellers in Nigeria but has also become a foreign exchange earner. Dehulled kernels are sun-dried and exported to cater for the African consumer overseas (Akubor, 2000).

African breadfruit seed is of high nutritional value. Each seed contains about 14-17% crude protein, 2.5% crude fibre, 35-60% carbohydrate and a good supply of vitamins and minerals (Akubor, 2000). The amino acid composition has also been highlighted to further buttress its nutritional potentials (Nwabueze, 2007).

Some of the starch properties obtained from mature fruits have been studied (Tumaalii and Wooton, 1988). Although the major commercial sources of starch are cereal grains seeds (Maize, wheat, rice), tubers (potato) and certain roots (sweet potato, cassava), several potential non conventional sources have been reported (Rincon and Perez, 1999). One of the potential alternative sources of commercial starch could be the seedless fruit, due to its high yield.

The potentials of African breadfruit as a nutrient resource and its position in the food cycle of the people makes its blending with other local ingredients is important way of expanding the scope of its utilization.

1.1   OBJECTIVES

The objectives of this study are to:

extract and analyse the starch content of African breadfruit seed.
determine the yield of starch in African bread fruit seed.
Know the starch concentrate as an ingredient requires that its utilization properties match a particular application.
JUSTIFICATION
This research work lead to the processes that are involved in the starch concentrate production and their utilization which may be valuable to the food and non food industry.