COMPARATIVE STUDY ON THE PHYTOCHEMICAL ANALYSES, ANTIOXIDANT ACTIVITIES AND PROXIMATE ANALYSES OF NESCAFE CAFFEINATED, DECAFFEINATED AND LIVEN ALKALINE COFFEE

ABSTRACT

The consumption of the popular beverage coffee, increases day by day. However, upcoming brands of coffee with health benefits made by claims of the product ignites curiosity in the components of the coffee. The current study deals with the phytochemical analysis, antioxidant capacity and proximate analysis of Liven Alkaline Coffee, Nescafe Caffeinated and Nescafe Decaffeinated coffee performed using standard procedures. The phytochemical analysis revealed higher contents of carbohydrates and alkaloids of 1.033mg/g and 3.098% respectively in Liven Alkaline coffee compared to Nescafe Caffeinated (0.415mg/g and 1.47%) and Nescafe Decaffeinated (0.342mg/g and 2.55%). Antioxidant capacity of samples was performed using three methods. Nescafe Caffeinated coffee showed the highest ferric-reducing antioxidant power (FRAP) value of 2.262 mg/g tannic acid equivalent, Nescafe Decaffeinated coffee (2.245mg/g TAE) and Liven Alkaline coffee (1.021 mg/g TAE). The lowest IC50 value which is correspondent to high antioxidant power of 249μg/ml for DPPH was found in Nescafe Caffeinated coffee compared to Liven Alkaline coffee (299.6 µg/ml) and Nescafe Decaffeinated coffee (328.1 µg/ml). TBARS assay showed the same trend with DPPH. Moisture, ash and reducing sugar contents were performed having values of 3.3% ash content for Liven Alkaline coffee, Nescafe Caffeinated (3.1%) and Nescafe Decaffeinated (2.8%). Nescafe Decaffeinated coffee had the lowest moisture content of 4.8% and the highest shelf life compared to Nescafe Caffeinated coffee (5.1%) and Liven Alkaline coffee (4.9%).  

 

Key Words: Coffee, Liven Alkaline, Caffeinated, Decaffeinated, Phytochemicals, Antioxidants.

TABLE OF CONTENTS

 

Title Page                                                       

Dedication                                                                                                                                 ii

Certification                                                                                                                               iii

Acknowledgement                                                                                                                     iv

Table of Content                                                                                                                        v

List of Figures                                                                                                                            ix

List of Tables                                                                                                                              x

Abstract                                                                                                                                     xi

CHAPTER ONE

1.0       Introduction                                                                                                                1

1.1       The Background to the Study                                                                                     1

1.2       The Statement of the Problem                                                                                                1

1.3       The Objective of the Study                                                                                        2

1.4       The Justification of the Study                                                                                    2

1.5       The Significance of the Study                                                                                    3

 

CHAPTER TWO

2.0       Literature Review                                                                                                       4

2.1       Liven Alkaline Coffee                                                                                                            4

2.2       Nescafe Caffeinated and Decaffeinated Coffee                                                         5

2.3       Coffea Beans                                                                                                               6

            2.3.1    The Process of Coffee Production                                                                  8

2.4       Overview of Phytochemicals                                                                                      10

            2.4.1    Phenols                                                                                                            11

            2.4.2    Alkaloids                                                                                                         12

            2.4.3    Terpenoids                                                                                                      12

            2.4.4    Saponins                                                                                                          13

            2.4.5    Tannins                                                                                                            13

            2.4.6    Flavonoids                                                                                                      13

2.5       Free Radicals                                                                                                              14

2.6       Antioxidants                                                                                                               15

2.7       Significance of Moisture Content                                                                              16

2.8       Significance of Ash Content                                                                                      17

2.9       Significance of Reducing Sugar Content                                                                   17

 

CHAPTER THREE

3.0       Materials and Methods                                                                                               18

3.1       Sample Material Collection                                                                                        18

3.2       Materials and Equipment                                                                                            18

3.3       Reagents and Chemicals                                                                                             18

3.4       Sample Preparation                                                                                                     19

3.5       Qualitative Phytochemical Analysis                                                                           19

            3.5.1    Presence of Tannins                                                                                        19

            3.5.2    Presence of Saponins                                                                                      19

            3.5.3    Presence of Flavonoids                                                                                   20

            3.5.4    Presence of Phenols                                                                                        20

            3.5.5    Presence of Terpenoids                                                                                   20

3.6       Quantitative Phytochemical Analysis                                                                         21

            3.6.1    Determination of Saponin content                                                                  21

            3.6.2    Determination of Alkaloid content                                                                 22

            3.6.3    Determination of Flavonoid content                                                              23

            3.6.4    Determination of Tannin content                                                                   23

            3.6.5    Determination of Polyphenol content                                                            24

            3.6.6    Determination of Carbohydrate content                                                         25

3.7       In vitro Antioxidant assays                                                                                         26

            3.7.1    Ferric reducing-antioxidant capacity                                                              26

            3.7.2    DPPH (1, 1-diphenyl-2-picryl hydrazyl) Scavenging activity assay              27

            3.7.3    Thiobarbituric Acid Reactive Species (TBARS) Assay                                 28

3.8       Proximate Analysis                                                                                                     29

3.9       Statistical Analysis                                                                                                      29

 

CHAPTER FOUR

4.0       Results                                                                                                                        30

4.1       Qualitative Phytochemical Screening                                                                         30

4.2       Quantitative Phytochemical Screening                                                                       32

4.3       In vitro Antioxidant assay                                                                                          34

            4.3.1    Ferric-reducing Antioxidant power                                                                34

            4.3.2    DPPH Radical Scavenging Activity                                                               34

            4.3.3    Thiobarbituric Acid Reactive Species Assay                                                 36

4.4       Proximate Analysis and Reducing Sugar                                                                   38

 

CHAPTER FIVE

5.0       Discussion, Conclusion and Recommendation                                                          39

5.1       Discussion                                                                                                                   39

5.2       Conclusion                                                                                                                  41

5.3       Recommendation                                                                                                        41

REFERENCES                                                                                                                    42

APPENDIX                                                                                                                           50