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

1.0 INTRODUCTION ………………………………………………………… 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

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

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

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

CHAPTER THREE

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

3.4.5.2 DPPH Radical Scavenging 

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

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

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

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

CHAPTER FOUR

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

4.1 Proximate composition of African star apple fruits before and

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

4.2 Mineral composition of African star apple before and

 during rainfall ………………………………………………. 29

4.3 Phytochemical composition of African star apple before and during 

rainfall ………………………………..…………………………….. 32

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

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

CHAPTER FIVE

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

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

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

REFERENCES

APPENDICES