Abstract

 Microbial profile and physicochemical changes in fermenting corn for pap production were determined in the laboratory. The maize grains were steeped for 72hours; wet milled, sieved and fermented for 48 hours separately at 320C by the maize natural microflora and a ten fold serial dilution was carried out. The yeast and bacterial isolated were identified using standard cultural, microscopic and biochemical methods. The pH of pap was determined using pH meter while temperature determined by using thermometer. Four bacterial were also isolated; Lactobacillus spp, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Lauconostoc spp. The temperature of fermenting maize remained relatively constant between 200C to 400C throughout the fermentation. Media used included nutrient agar (NA), which is suitable for the growth of most bacteria and was used for routine work in culturing microorganisms; deMan Rogosa and Sharp-medium  (MSR); plate count agar; Sabauroude dextrose agar (SDA) was used for Mycological analysis and MacConkey Agar (MCA) was used to enhance the growth of Gram-negative organisms.

The pH decreased and acidity increased during fermentation. Despite the unhygienic wet-milling and wet sieving processes involved in the preparation of pap, the low pH of the fermented products would make them safe for consumption. Appropriate safety measures and good manufacturing practices will ensure good quality of product. The microorganisms isolated are essential in the fermentation of corn and also caused the physicochemical changes that occurred in fermenting corn for pap production.

TABLE OF CONTENTS

Cover page  

Title page i

Certification ii

Dedication iii

Acknowledgement iv

Table of content v

List of tables vi

Abstract vii

CHAPTER ONE

1.0 Introduction 1

1.1 Aims 3

1.2 Objectives 3

CHAPTER TWO

2.0 Literature review 4

2.1 Corn 4

2.1.1 Origin of Corn 4

2.1.2 Structure of the Corn 5

2.2 Physical Composition of Corn 5

2. 5 Chemical composition of Pap 6

2. 5.1 Protein 6

2.5. 2 Oil and Related Compounds 6

2.5.3 Minerals/Ash Content 6

2.5.4 Moisture 6

2.5.5 Vitamins 7

2.5.6 Carbohydrate 7

2.6 Utilization of Corn 7

2.7.1    Pap 8

2.8 Pap fermentation 8

2.9 Microbial properties of Pap 9

2.10 Physicochemical changes in fermenting corn for 10

Pap production 

2.10.1 Physical changes in fermenting corn for Pap production  10

2.10.2 Chemical changes 11

2.10.3 Nutritional changes 12

CHAPTER THREE

3.0 Materials and methods 14

3.1 collection of Sample 14

3.2 Sample processing 14

3.3 Culture Media Preparation and Sterilization 16

3.4. Preparation of Samples 15

3.5 Inoculations and culturing 16

3.6 Determination of physical parameters 16

3.6.1 Determination of Temperature 16

3.6.2 Determination of pH 16

3.7 Determination of chemical parameters 16

3.7.1 Determination of Vitamin using Spectrophotometer 16

3.7.2 Protein Determination 17

3.7.3 Ash Determination 17

3.7.4 Fat Determination 17

3.8.1 Colony Count of the isolates 18

3.8.2 Isolation of microorganism 18

3.10 Characterization and identification of bacteria isolates 18

3.10.1 Gram Staining 18

3.10.2 Coagulase test 29

3.10.3 Oxidase test 29

3.10.4 Citrate utilization test: 29

3.10.5 Motility Test 20

3.10.6 Indole Test 20

3.10.7 Methyl Red Test 20

3.10.8 Sugar Fermentation 21

3.11.1   Characterization and identification of fungi isolates 21

3.11.2     Microscopic identification of fungi 21

CHAPTER FOUR

4.0 Results 22

CHAPTER FIVE

5.1 Discussions  29

5.2 Conclusion 31

REFERENCES