Nutritional Evaluation As Influenced by Cooking of Some Saudi Traditional Dishes
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Nutritional Evaluation as Influenced by Cooking of Some Saudi Traditional Dishes By Abdulatif Saleh Hamd Al Jasser B,Sc, (Food Technology) - 1982 M.Sc. (Human Nutrition) - 2003 King Saud University Late supervisor Profesor Abdullahi Hamid El Tinay Current supervisor Profesor Elfadil Elfadl Babiker A thesis submitted to the University of Khartoum in fulfillment for the requirements of the degree of Doctor of Philosophy (Agric.) Department of Food Science and Technology University of Khartoum Faculty of Agriculture December 2010 DEDICATION To my father To my sons and daughters To my wife (Um Abdallah) WITH LOVE ACKNOWLEDGEMENTS Thanks in beginning and at last for Allah the Gracious, the great for helping me going through and finishing this work. I wish to express my deep gratitude and sincere thanks to my late supervisor Professor Abdullahi Hamid El Tinay and my current supervisor Professor Elfadil Elfadl Babiker for his kindness, continuous interest, helpful encouragement, and supervision through- out the progress of this study. Also I would like to express my sincere thanks to my co- supervisor Dr. Seif Eldeen Bashier Ahmed for his great help and interest throughout the stages of the study and Dr. Nabila El Amir Yousif for her help and encouragement. My deep thanks to small and big family for encouraging me to fulfill this study. Finally, I am indebted to all those who in one way or another help me, specially Mr. Amin Abu Alkeer for statistical analysis all the staff members of the Department of Food Science and Technology, Faculty of Agriculture, University of Khartoum. TABLE OF CONTENTS DEDICATION ......................................................................................................... i ACKNOWLEDGEMENTS .................................................................................... ii TABLE OF CONTENTS ....................................................................................... iii LIST OF TABLES .................................................................................................. v ABSTRACT ........................................................................................................... vi ARABIC ABSTRACT ......................................................................................... viii CHAPTER ONE: INTRODUCTION ..................................................................... 1 CHAPTER TWO: LITERATURE REVIEW ......................................................... 3 2.1 Traditional Foods .............................................................................................. 3 2.1.1 Food habits and cultural aspects ................................................................ 5 2.1.2 Nutritive value ............................................................................................ 7 2.1.3. Commonly consumed dishes in Saudi Arabia ........................................ 18 2.1.3.1. Kabsa ................................................................................................ 18 2.1.3.2. Hunaini ............................................................................................. 18 2.1.3.3. Garish ............................................................................................... 19 2.1.3.4. Gursan .............................................................................................. 20 2.1.3.5 Saleeg ................................................................................................ 21 2.1.3.5.1. Areas of consumption ................................................................... 21 2.2. Anti-nutritional factors ................................................................................... 21 2.2.1. Phytate ..................................................................................................... 23 2.2.1.1. Chemistry and occurrence of phytate ............................................... 24 2.2.1.2. Phytic acid content ........................................................................... 25 2.2.1.3. Interaction of phytic acid with mineral and proteins ....................... 26 2.2.1.4. Effect of processing on phytate ........................................................ 27 2.2.2. Tannins .................................................................................................... 31 2.2.2.1. Tannins as anti-nutrient .................................................................... 33 2.2.2.2. Reduction of tannins ........................................................................ 35 2.3. In vitro protein digestibility (IVPD) .............................................................. 39 2.3.1. Effect of processing on In vitro protein digestibility (IVPD) ................. 40 2.4. Proteins and amino acids composition ........................................................... 41 2.5. Vitamins and minerals composition ............................................................... 44 CHAPTER THREE: MATERIALS AND METHODS ........................................ 45 3.1 Materials .......................................................................................................... 45 3.2 Chemical analysis of samples ......................................................................... 47 3.2.1 Moisture content ...................................................................................... 47 3.2.2 Crude oil ................................................................................................... 47 3.2.3 Crude protein ............................................................................................ 47 3.2.4 Crude fiber ............................................................................................... 48 3.2.5 Total ash ................................................................................................... 48 3.2.6 Carbohydrates determination ................................................................... 48 3.2.7 Total energy ............................................................................................. 49 3.3. Determination of mineral content by atomic absorption spectrophotometer . 49 3.4 Determination of anti-nutritional factors ........................................................ 49 3.4.1 Determination of tannin content .............................................................. 49 3.4.2 Determination of phytate content ............................................................. 50 3.4.3 Standard curve preparation of phytic acid ............................................... 51 3.4.4 Trypsin inhibitor activity assay ................................................................ 52 3.5 In vitro protein digestibility ............................................................................ 52 3.6 In vitro starch digestibility .............................................................................. 53 3.7 Amino acid ...................................................................................................... 53 3.7.1 Amino acid analysis ................................................................................. 53 3.7.2 Amino acids scores calculation ................................................................ 54 3.8 Calculation protein efficiency ratio (C. PER) ................................................. 54 3.9 Statistical analysis ........................................................................................... 54 CHAPTER FOUR: RESULTS AND DISCUSSION ........................................... 55 4.1 Proximate composition of traditional Saudi dishes ......................................... 55 4.2 Mineral content of traditional Saudi dishes .................................................... 59 4.3 Antinutritional factors ..................................................................................... 62 4.3.1 Tannin content of Saudi traditional dishes ............................................... 62 4.3.2 Phytate content of Saudi traditional dishes .............................................. 65 4.3.3 Trypsin inhibitor activity of Saudi traditional dishes ............................... 67 4.4 In vitro protein digestibility of Saudi traditional dishes.................................. 69 4.5 In vitro starch digestibility of Saudi traditional dishes ................................... 71 4.6 Amino acids content ........................................................................................ 73 4.6.1 Amino acids content of dishes ingredients .............................................. 73 4.6.2 Amino acid conent of traditional dishes .................................................. 76 4.7 Calculated protein efficiency ratio of Saudi traditional diets .......................... 86 CHAPTER FIVE: CONCLUSION AND RECOMMENDATIONS ................... 89 5.1 Conclusions ..................................................................................................... 89 5.2 Recommendations ........................................................................................... 90 REFERENCES ...................................................................................................... 91 LIST OF TABLES Table Page 3.1 Ingredients of foods used in the study 46 4.1 Proximate composition fresh weight of traditional diet 46 4.2 Proximate composition dry weight of traditional diet 58 4.3 Minerals content of tradition foods mg/100 sample 60 4.4 Tannin content (%) of traditional diets 63 4.5 Phytic acid content of traditional diets 66 4.6 Trypsin inhibitor activity of traditional