Thesis Abstract

Abstract
Yam is a widely consumed staple food in many regions of the world, particularly in Africa, Asia, and the Caribbean. The production of yam flour from yam chips is a common practice that extends the shelf life of yam and provides consumers with a convenient and versatile product. This research project aimed to investigate the process of producing yam flour from yam chips and to assess the quality characteristics of the resulting flour. The production process involved peeling, slicing, blanching, drying, milling, and sieving the yam chips to obtain yam flour. Different varieties of yam were used in the study to determine if there were any significant differences in the quality of the flour produced. The moisture content, color, particle size distribution, and pasting properties of the yam flour were analyzed to evaluate its quality. The results showed that the production of yam flour from yam chips was successful, with the final product having a moisture content within the acceptable range for good quality flour. The color of the flour varied depending on the variety of yam used, with some varieties producing a lighter-colored flour than others. The particle size distribution of the flour was uniform, indicating that the milling and sieving processes were effective in producing a consistent product. The pasting properties of the yam flour were determined using a Rapid Visco Analyzer (RVA), which revealed the viscosity profile of the flour during heating and cooling. The peak viscosity, breakdown viscosity, final viscosity, and setback viscosity of the flour were measured to assess its suitability for various food applications. The results indicated that the yam flour had good pasting properties, making it suitable for use in products such as porridge, cakes, and soups. Overall, the production of yam flour from yam chips is a feasible process that can help to reduce post-harvest losses of yam and provide consumers with a convenient and nutritious product. Further research could focus on optimizing the production process to improve the quality and yield of yam flour, as well as exploring new applications for this versatile ingredient.

Thesis Overview

The project dealt on the production of yam flour from yam chips. The yams were peeled and washed, 100grams samples coded sample A to G were subjected to two different drying conditions. Some were dried using the sun drying method while the others were dried through oven drying method kept at constant temperature of 500C, sodium bi-carbonate was added to some of the samples, all these were done to obtain a flour with the best colour and texture quality. From the results obtained, it was observed that sample B (yam boiled with sodium bi-carbonate and dried with oven) gave the best result and quality when tested with hot water, this was as a result of the drying condition used, the constant temperature maintained and the presence of the sodium bi-carbonate used which helped in achieving the result. Generally, the samples dried through the oven drying method at 500C gave better colour and result of the yam flour when tested with hot water more than other samples dried by sun drying and this was due to the stability in temperature in the oven drying method used.

CHAPTER ONE

1.0       INTRODUCTION

1.1         Background Of The Study

Yam (dioscorea spp.) is a multi-species crop that originated principally from Africa and Asia before spreading to other parts of the world (Hahn et al.,1987). It belongs to the family of dioscoreae within the genus dioscorea and serves as a staple crop in west Africa.(Asiedu et al., 1992). There are many cultivars of yam, though only six are important as staple foods in the tropics. the economically important species grown are Dioscorea rotundata(white yam),D.alata (yellow yam),D.bulbifera (aerial yam), D.esculenta (Chinese yam) and D.dumenterum (trifoliate yam). Yam tubers which is the most important part of the plants can be stored longer than other root and tuber crops. This ensures food security even in times of general scarcity. Yam is the third most important tropical root and tuber crop after cassava and sweet potato (fu et al., 2005). West Africa is the leading producer of yam and grows over 90% of the worldwide production (40 tonnes fresh tuber/year) followed by the west Indians where Jamaica is the leading producer (FAOSTAT,2004). Nigeria is the world’s largest producer of yams followed by Ghana, ivorycoast and togo (FAO,2003). Both fresh tubers and yam flour are now exported from Ghana and Nigeria to developed countries such as united kingdom and united states of America. These are mostly patronized by emigrants from growing regions according to the Nigerian export promotion council (NEPC) Nigeria realized N56 billion in 2007. Sustainable production and utilization of yam are important steps in enhancing food security.