Refining of Soybean Oil

Refining of Soybean Oil

ABSTRACT

This project work studied the refining of crude soybean oil extracted from soybean seed using alkali /caustic refining method. The work was carried out using phosphoric acid for the degumming /pretreatment process and sodium hydroxide for the neutralization /refining of the oil. Certain tests were carried out on both the crude and refined oil such as saponification value, acidic value, iodine value, specific gravity and viscosity, the results obtained after the tests include 42.075, 164.28, 589.05, 0.8944 and 0.038 respectively for refined oil and 44.88, 109.52, 448.8, 0.8148 and 0.035 respectively for the crude oil.

TABLE OF CONTENTS

Title page … … … … … … … … … … i
Certification… … … … … … … … … … ii
Dedication… … … … … … … … … … iii
Acknowledgement… … … … … … … … … iv
Abstract … … … … … … … … … … … v
Table of contents… … … … … … … … … vi
List of table … … … … … … … … … … viii
List of figure… … … … … … … … … … ix
CHAPTER ONE
1.1 Introduction… … … … … … … … … 1
1.2 Background of the study… … … … … … … 3
1.3 Statement of the problem… … … … … … … 9
1.4 Objectives of the study… … … … … … … 9
1.5 Scope of the study… … … … … … … … 10
CHAPTER TWO
2.0 Literature Review… … … … … … … … 11
2.1 Historical Background of Soybeans … … … … … 11
2.1.1 Composition of Soybean … … … … … … 13
2.1.2 Soybean Chemistry… … … … … … … … 14
2.2. Food Beans and Oil Beans… … … … … … … 15
2.2.1 Health and soybean Foods… … … … … … … 17
2.3. Composition of Soybean Oil… … … … … … 19
2.3.1 Triglyceric Structure… … … … … … … 20
2.3.2 Physical Properties of Soybean Oil… … … … … 21
2.4. Recovery of Oil from Soybean… … … … … … 24
2.4.1 Storage and Preparation of Beans… … … … … 24
2.4.2 Solvent Extraction… … … … … … … … 25
2.4.3 Oil Storage… … … … … … … … … 26
2.5. Edible Oil Processing… … … … … … … … 27
2.5.1 Basic Processing Operations and
Principle Edible Oil Product… … … … … … 28
2.5.2 Oil Degumming and Soybean Lecithin… … … … 29
2.6. Refining Of Soybean Oil… … … … … … … 31
2.6.1 Chemical (Caustic) Refining… … … … … … 33
2.6.2 Physical (Steam) Refining… … … … … … 35
2.7. Bleaching… … … … … … … … … … 36
2.7.1 Bleaching Process… … … … … … … … 38
2.7.2 Types of Adsorbents Used… … … … … … 40
2.8. Deodourization… … … … … … … … … 41
2.8.1 Deodourization of Soybean Oil… … … … … 42
2.8.2 Effect of Deodourization on Oil Quality… … … … 43
2.9. Evaluation of Finished Oil Quality… … … … … 43
2.9.1 Storage and Handling … … … … … … … 44
CHAPTER THREE
3.0 Materials and Methods… … … … … … … 46
3.1 Materials Used… … … … … … … … … 46
3.2 Equipments Used… … … … … … … … 46
3.3 Reagents Used… … … … … … … … … 47
3.4 Preparation of Reagents… … … … … … … 48
3.5 Procedures… … … … … … … … … 49
3.6 Testing of Oil… … … … … … … … … 50
3.6.1 Test for Saponification Value… … … … … … 51
3.6.2 Test for Iodine Value… … … … … … … 51
3.6.3 Test for Acidic Value… … … … … … … 52
3.6.4 Test for Specific Gravity… … … … … … … 52
3.6.5 Test for Viscosity… … … … … … … … 53
CHAPTER FOUR
4.0 Results and Discussion… … … … … … … 54
4.1 Results… … … … … … … … … … 54
4.2 Titration Readings… … … … … … … … 55
4.3 Discussion … … … … … … … … … 58
CHAPTER FIVE
5.0 Conclusion and Recommendation… … … … … 59
5.1 Conclusion… … … … … … … … … … 59
5.2 Recommendation… … … … … … … … 59
References … … … … … … … … … 60
Appendices… … … … … … … … … 62

LIST OF TABLE
Table 2.1 Composition of soybean oil… … … … … 19
Table 2.2: Average composition for crude
and refined soybean oil… … … … … … 20
Table2.3 Selected physical properties of soybean oil… … … 22
Table 2.4 Density of soybean at several temperatures… … 22
Table 2.5 Smoke, flash and fire points‟
temperatures of soybean oil … … … … … 23
Table 2.6 Classical refining of soybean oil … … … … 32
Table 3.1 Degummed soybean oil with different
quantities of sodium hydroxide … … … … … 50
Table 4.1 Result of the degummed soybean oil… … … … 54
Table 4.2 Result of the canstic refining of soybean
oil with different quantities… … … … … … 54
Table 4.3 Test results of the properties of the
refined oil and crude oil. … … … … … … 55
Table 4.4 titration reading of saponification value of refined oil… 55
Table 4. 5 titration reading of Iodine value of refined oil … … 56
Table 4.6 Titration reading of Acidic value of refined oil… … 56
Table 4.7 titration reading of saponification value of crude oil… 56
Table 4.8 titration reading of iodine value of crude oil… … 57
Table 4.9 titration of acidic value of crude oil… … … … 57

LIST OF FIGURE
Fig 1:1-Generation flow sheet for refining and processing
fats and oils… … … … … … … … … 4
Fig 2:1 Front View of Soybean Seed … … … … … … 12
Fig 2.2 A general outline of the soybean food use based
on classification of oil and food Bean… … … … … 16

CHAPTER ONE

1.1 INTRODUCTION

Refining of vegetable oils is essential to ensure removal of germs, phosphatides and free fatty acids (F.F.A) from the oil, to impact uniform colour by removal of colouring pigments and to get rid of unpleasant smell from the oil by removal of odiferous matter.

Refining is carried out either on batch operation or as continuous operation. With certain oils even physical refining can be carried out instead of chemical.

For processing less than thirty tons of oil per 24 hours, and when oil has F.F.A content of 1 percent or less normally batch process is recommended. Batch process involves low capital investments, simplicity of operation and low maintenance, making refining economically a viable proposition even at capacity as low as 10 tonnes per 24 hours. (According to Dietary fats and oils in Human Nutrition. (Rome 1977)).

Soybean oil is produced from the seed of the legume called soja max or calyclue max. The seed has an oil content of about 20%, it is the highest volume vegetable oil produced in the world. The crude oil is obtained by pressing or solvent extraction method. The main uses of the oil after refining, bleaching and deodorization and partial hydrogenation are in the manufacture of Magrine and shortening. The unhydrogenated oil is also used in blends with other oil but its tending to revert when exposed to air or higher temperatures limits its use. (Hand book of industrial chemistry, Reigel et al, (2003)).
Soybean oil is also used extensively in the manufacture of drying oil products.

Crude soybean oil of good quality has a lighter amber colour which upon alkali refining is reduced to the light yellow colour of most vegetable seed oils. Soybean oil produced from green or immature beans may contain sufficient chlorophyll to have a greenish cast but this is not usually very evident until after the yellow red pigment of the oil have been bleached in hydrogenation (G.S Breck and S.C Bhatia, 2008).

The crude oil particularly that obtained by solvent extraction contains relatively large amount of non-glyceride materials consisting chiefly of phosphatide. They are removed by water washing during refining processes. The phosphatides removed by water washing are converted to soybean lecithin. The free fatty acid content of good crude soybean oil like that many other vegetable oil is slightly in excess of 0.5 percent. (Hand book of Industrial chemistry,Reigel et al (2003)).

REFERENCES

Akpan U.G, Jimoh A., Mohammed A.D. Extraction Characterization of oil seed.

Breck G.S and Bhatia S.C (2008). Handbook of industrial fats and oil: Vol 2.

Erickson D.R (1983). Jaocs. vol 60, Asa Saint Louis (U.S.A).

Heldman Dennis R. (1975). Food processing Engineering. West Port Connecticut. The AVI Publishing Company.

Kirk. Othmer (1964). Encyclopedia of chemical Technology: 2nd Edition: Vol. 4.

National Occupational Health and Safety Commission (1991). Draft National Code for spray painterly. Canberra, Australia.

Perry, R.H (1988). Chemical Engineering Handbook: 5th Edition USA. McGraw Hill Book Company

Pryde E.H. Handbook of soy oil processing and utilization Usda-peoria.

Reigel (2003). Handbook of industrial chemistry:vol 4.

Weise E A. (1983). Oil seed crops. Tropical Agricultural series Longman.

Young F.V.K (1981). Symposium on soybean processing: 5th Edition (U.S.A).