ABSTRACT

The study investigated the chemical changes inAfrican Star Apple (Chrysophyllum albidium) fruits prior to onset of rains and during the rainy season, with the aim of ascertainingits optimum consumption quality. The fruits were harvested from the School of Agriculture and Agricultural Technology, Federal University of Technology, Akure. Chemical analysis was carried out on the edible parts of the African star apple fruit(both the pulp and whitish seed coat). The result showed significant increases in moisture contents (30.20% - 35.83%), protein (5.52%-6.64%) and fibre (12.78%-15.67%) for both the pulp and seed coat during the rainfall.The fat, ash and carbohydrate contents were however reduced (12.20% - 3.50%), (2.47% -2.40%) and(37.31% - 36.17%) respectively. Mineral contents (potassium, phosphorus, iron copper andzinc) also increased in the pulp and seed coat during the rainfall. The antioxidant properties of the pulp and seed coat also increased during rainfall except for the metal chelating activity. For the phytochemical screening, alkaloid, tannin, saponin, flavonoid, terpenoid, phlobatannin and cardiac glycoside were all present, while the presence of flavonoid was increased during the rains.

The results thus corroborated the tradition in South West Nigeria which forbids consumption of African Star apple before onset of rains. The fruits are better consumed and utilized during the rains when the chemical composition is at optimum levels. Harvest is thus recommended during the rainfall season so as to maximize the nutritional benefits of African Star Apple fruits.

TABLE OF CONTENT

TITLE PAGE………..……………………………………………………………..i

ABSTRACT…………..…………………………………………………………..ii

CERTIFICATE………..………………………………………………………iii

DEDICATION………………………………………………………………..iv

ACKNOWLEDGEMENT…………………………………………………………v

TABLE OF CONTENT………………………………………………………..vi

LIST OF FIGURES     …………………………………………………………………vii

LIST OF TABLES……………………………..……………………………………….  viii

CHAPTER ONE

1.0INTRODUCTION…………………………………………………………1

1.1 Background of the study………………………………………………………....1

1.2 Justification of the study………………………………………....………………2

1.3 Aim and objectives of the study……………………………………………………2

CHAPTER TWO

2.0 LITERATURE REVIEW………………………………………………….4

2.1Botanic Description Of Chrysophylum Albidum (African Star Apple Fruit)…...4

2.2Nutritional Qualities Of African Star .…………………………………………6

2.3Post Harvest Physiology Of Chrysophyllum Albidum ………………………..9

CHAPTER THREE

3.0MATERIALS AND METHOD…………………………………………13

3.1Sources of Raw Materials………………………………………..………..13

3.2Preparation of plant material ……………………………………………………..13

3.3Extraction of plant material………………………………..………13

3.4Chemical Analysis……………………..………………………………..15

3.4.1Proximate composition …….………………………………………..15

3.4.1.1Moisture content determination…………………………………15

3.4.1.2Crude fat determination……………………………………….15

3.4.1.3Crude protein determination……………………………………16

3.4.1.4Determination of Ash…………………………………………17

3.4.1.5Crude Fiber Determination……………………………………17

3.4.1.6Carbohydrate Determination………………………………..18

3.4.2Mineral Determination………………………………………………..19

3.4.3Vitamin C Determination……………………………………………..20

3.4.4Phytochemical analysis………………………………………………..20

3.4.4.1Alkaloids……………………………………………………….20

3.4.4.2Flavonoids………………………………………………………21

3.4.4.3Saponins………………………………………………………..21

3.4.4.4Tannins…………………………………………………………21

3.4.4.5Phlobatanins……………………………………………………21

3.4.4.6Terpenoids………………………………………………………22

3.4.4.7Cardiac glycosides……………………………………………..22

3.4.5Evaluation of Antioxidant Activity……………………………………22

3.4.5.1Metal Chelating Activity Assay………………………………22

3.4.5.2DPPH Radical Scavenging 

(1, 1-diphenyl-2-picrylhydrazyl) Activity Assay…………….22

3.4.5.3Lipid Peroxidation Inhibition Activity Assay………………..23

3.4.5.4Hydroxyl Radical Scavenging Activity Assay………………23

3.5Statistical Analysis………………………………………………………24

CHAPTER FOUR

4.0RESULT AND DISCUSSION………………………………………..25

4.1Proximate composition of African star apple fruits before and

 during rainfall    …………………………..………..…………………………25

4.2Mineral composition of African star apple before and

 during rainfall……………………………………………….29

4.3Phytochemical composition of African star apple before and during 

rainfall………………………………..……………………………..32

4.4 Vitamin C composition of African star apple before and during rainfall ……34

4.5Antioxidant Activity of African star apple before and during the rainfall ……..37

CHAPTER FIVE

5.0CONCLUSION AND RECOMMENDATIONS………………………….42

5.1Conclusion………………………………………………………….42

5.2Recommendations…………………………………………………………43

REFERENCES

APPENDICES