Determination Of Microbial Profiles And Physicochemical Changes In Fermenting Corn For Pap Production

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