i PRODUCTION AND EVALUATION OF BREAKFAST CEREALS FROM BLENDS OF AFRICAN YAM BEAN (Sphenostylis stenocarpa), MAIZE (Zea mays) AND DEFATTED COCONUT (Cocos nucifera). BY USMAN, GRACE OJALI PG/M.Sc./09/50997 DEPARTMENT OF FOOD SCIENCE AND TECHNOLOGY, UNIVERSITY OF NIGERIA, NSUKKA. NOVEMBER, 2012 i TITLE PAGE PRODUCTION AND EVALUATION OF BREAKFAST CEREALS FROM BLENDS OF AFRICAN YAM BEAN (Sphenostylis stenocarpa), MAIZE (Zea mays) AND DEFATTED COCONUT (Cocos nucifera). A DISSERTATION SUBMITTED TO THE DEPARTMENT OF FOOD SCIENCE AND TECHNOLOGY, FACULTY OF AGRICULTURE, UNIVERSITY OF NIGERIA, NSUKKA, IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE AWARD OF M.Sc. IN FOOD SCIENCE AND TECHNOLOGY. BY USMAN, GRACE OJALI PG/M.Sc./09/50997 DEPARTMENT OF FOOD SCIENCE AND TECHNOLOGY, UNIVERSITY OF NIGERIA, NSUKKA. NOVEMBER, 2012 ii CERTIFICATION USMAN, GRACE OJALI, a Post-graduate student in the Department of Food Science and Technology, Faculty of Agriculture, University of Nigeria, Nsukka, with Registration Number: PG/M.Sc./09/50997 has satisfactorily completed the requirements for award of the degree of Master of Science in Food Science and Technology. The work embodied in this dissertation is original and has not been submitted in part or full for any other diploma or degree of this or other university. ------------------------------------ ------------------------------------- DR G.I OKAFOR MR C.S. BHANDARY (SUPERVISOR) (HEAD OF DEPARTMENT) ----------------------- ---------------------- Date Date iii DEDICATION This work is dedicated to the Holy Spirit, my source of inspiration and my family, for helping me in ways I can never quantify. iv ACKNOWLEDGEMENTS The successful completion of this research was made possible through the efforts and commitment of so many to whom I owe my appreciation. My foremost thanks go to the Almighty God, who makes all things possible to them that believe in Him. My sincere thanks goes to my Supervisor, Dr G.I. Okafor, whose advice, patience, dedication and relentless efforts led to the successful completion of this work. I am also grateful to, Mr. C.S. Bhandary and the entire staff of the Department: Prof P. O. Ngoddy, Prof. T. M. Okonkwo, Prof. (Mrs.) N. J. Enwere, Dr (Mrs.) J.C. Ani, Dr. P.O. Uvere, Dr. J. I. Eze, Dr. (Mrs.) I. Nwaoha and Mrs. Omah, for imparting the knowledge and skills that equipped me throughout the period of this study and made this work a reality. I owe my parents, Prof. and Mrs. S.S. Usman a lot of appreciation for their patience, encouragement, love and support, which motivated me at every stage of this work. I fondly appreciate my siblings, Adaji, Chide, Ugbede and Baby Praise for always being there for me. I also extend my sincere appreciation to my brethren of the Graduate Students' Fellowship, University of Nigeria, Nsukka for always making me feel at home. Lastly, my profound gratitude goes to all my friends; Mary, Lucy, Toyin, Barrister, fellow professional colleagues and all those whose names are not mentioned. I love you all. v ABSTRACT Six samples were generated by mixing the flours (AYB+ maize composite) with graded levels of defatted coconut flour (100:0, 90:10, 80:20, 70:30, 60:40, 50:50), sugar, salt, sorghum malt extract and water. Breakfast cereals were produced by roasting (280°C) -a dry heat treatment process to gelatinize and semi-dextrinize the starch in order to generate dry ready to eat products from blends of African yam bean (Sphenostylis stenocarpa), maize (Zea mays) and defatted coconut (Cocos nucifera) cake. They were subjected to proximate, functional, sensory, minerals, vitamins, anti-nutrients, amino acids and microbial analyses. The products obtained were also served dry (without added water), with cold water, cold milk and warm milk to 15 panelists along with Weetabix (commercial control) to evaluate for appearance, consistency, flavour, taste, aftertaste, mouth feel, and overall acceptability using a 9 point Hedonic scale (1=dislike extremely, 9=like extremely). The results revealed the following ranges: proximate parameters (%): moisture (3.38-4.20), protein (15.68-18.26), fat (1.84-2.02), crude fiber (6.70-9.08), ash (5.29-7.36), carbohydrates (60.96-64.53), and energy (327.54-347.72Kcal). Functional properties were: pH (4.70- 6.56), bulk density (0.29- 0.71g/ml), water absorption capacity (68.31- 76.39%), oil absorption capacity (0.87- 1.32%), foam capacity (2.48- 3.49%), viscosity (19.73-31.08%), invitro-protein digestibility (66.30- 82.2%), and gelation capacity (75.32- 89.66%). Mineral analysis showed the following ranges (mg/100g): calcium (169-213), magnesium (290-430), potassium (88-191), manganese (5.92-7.99), iron (9.81-14.1), copper (0.58- 0.86), sodium (7.62- 9.97), zinc (2.11- 3.35). Vitamins analysis also revealed the following ranges (mg/100g): B1 (0.09-0.31), B2, (0.32-0.43), B6 (0.13- 0.26), B12 (0.74-1.01) and C (1.70- 2.65). Results for the anti-nutrients showed the following ranges (mg/100g): phytates, (0.38-1.25), oxalate (0.076-0.302), hemagluttinins, (0.10- 0.29) and tannins (0.00064-0.0016). Amino acids detected ranged as follows (mg/100g): phenylalanine (190-320), valine (160-240), threonine (560-810), tryptophan (380-520), isoleucine (110-220), methionine (10-100), histidine (160-240), arginine (180-510), lysine(90-250), leucine (590-810), cysteine (210-340), alanine (110-220), glycine (460-750), serine(80-120), aspartic acid (10-40), glutamic acid (10-40), asparagine (190-520), glutamine (100-300) and proline (30-50). Microbial analysis revealed the following ranges: bacteria count, 0.5x10 -1.51x102 Cfu/g, mold count, 0.0x10- 0.6x10 Cfu/g, while coliform was not detected. The sensory results revealed that the samples obtained were acceptable to the panelists, and there were no significant differences (p>0.05) between the control (Weetabix) and the samples in terms of overall acceptability when served with cold water, while significant (p<0.05) differences existed when served dry, with cold milk and hot milk. vi TABLE OF CONTENTS Page Title page - - - - - - - - i Certification - - - - - - - - ii Dedication - - - - - - - - iii Acknowledgments - - - - - - - - iv Abstract - - - - - - - - v Table of Contents - - - - - - - - vi List of Tables - - - - - - - - ix List of Figures - - - - - - - x Appendices - - - - - - - - xi 1.0 CHAPTER ONE: INTRODUCTION - - - - 1 1.1 Statement of Research Problem - - - - - 3 1.2 Significance of the study - - - - - - 4 1.3 Objective of the Study - - - - - - 4 2.0 CHAPTER TWO: LITERATURE REVIEW - - - 5 2.1 Breakfast and its importance - - - - - 5 2.1.1 Constituents of a Healthy Breakfast - - - - - 7 2.1.2 History of Breakfast Cereals - - - - - - 7 2.1.3 Classification of Breakfast Cereals - - - - - 8 2.2 Cereals - - - - - - - - 10 2.2.1 Maize Production and Utilization - - - - - 11 2.2.2 Varieties of Maize - - - - - - - 12 2.2.3 Nutritional Value of Maize - - - - - - 12 2.3 Legumes - - - - - - - - 13 2.3.1 World Production of Legumes - - - - - 13 2.3.2 Nutritional Relevance of Legumes - - - - - 14 2.3.3 Anti-nutritional Factors in Legumes - - - - - 14 2.4 Underutilized Legumes - - - - - - 16 2.5 African Yam Beans (AYB) - - - - - - 17 2.5.1 Nutrient Composition of African Yam Beans - - - 17 2.5.2 Potentials of African Yam Beans - - - - - 18 2.5.3 Factors Limiting the Use of African Yam Beans - - - 18 2.6 Coconut - - - - - - - - 19 2.6.1 Origin and Morphology of Coconut - - - - - 19 2.6.2 Natural habitat of Coconut - - - - - - 19 2.6.3 Nutritional Value of Coconut - - - - - 19 2.6.4 Coconut in Traditional and Modern Medicine - - - 21 2.6.5 Coconut as a Source of Dietary Fiber in Foods - - - 22 2.7 Production and Utilization of Sorghum - - - - 22 2.7.1 The use of Sorghum for the production of malt extract - - 23 3.0 CHAPTER THREE: MATERIALS AND METHODS - - 24 3.1 Material Procurement - - - - - - 24 3.1.1 Sample Preparation - - - - - - - 24 3.1.2 Production of Maize Flour - - - - - - 24 vii 3.1.3 Production of African Yam Beans Flour - - - - 26 3.1.4 Production of defatted Coconut flour - - - - 28 3.1.5 Production of Sorghum Malt Extract - - - - 30 3.2 Products Formulation - - - - - - 32 3.3 Analysis of Samples - - - - - - 35 3.3.1 Proximate Composition - - - - - - 35 3.3.1.1 Determination of Moisture Content - - - - - 35 3.3.1.2 Determination of Crude Fat Content - - - - - 35 3.3.1.3 Determination of Protein Content - - - - - 36 3.3.1.4 Determination of total Ash Content - - - - - 36 3.3.1.5 Determination of Crude Fiber Content - - - 37 3.3.1.6 Determination of Carbohydrate - - - - - 37 3.3.1.7 Determination of Energy Value - - - - - 37 3.4 Functional Properties Determination - - - - 37 3.4.1 Determination of pH - - - - - - - 37 3.4.2 Determination of Bulk Density - - - - - 38 3.4.3 Determination of Water/ Fat Absorption Capacity - - - 38 3.4.4 Determination of Foam Capacity - - - - - 38 3.4.5 Determination of Viscosity - - - - - - 38 3.4.6 Determination of In-vitro Protein Digestibility - - - 39 3.4.7 Determination of Gelation Capacity - - - - - 39 3.5 Sensory Evaluation - - - - - - - 39 3.6 Determination of Anti-nutritional Factors - - - - 40 3.6.1 Determination of Phytate or Phytic Acid - - - - 40 3.6.2 Determination of Tannin - - - - - - 40 3.6.3 Determination of Oxalate - - - - - - 41 3.6.4 Determination of Hemagluttinin - - - - - 41 3.7 Determination of Mineral content - - - - - 42 3.8 Determination of Vitamin content - - - - - 42 3.8.1 Determination of Vitamin B1 - - - - - 42 3.8.2 Determination of Vitamin B2 - - - - - 43 3.8.3 Determination of Vitamin B6 - - - - - 44 3.8.4 Determination