A Comparison of Oil Extraction Methods

Linton Bailey1, Mary Besong2 and Alberta N.A. Aryee2

1 Hospitality and Tourism Management, College of Agricultural Science & Education, Passley Gardens, Port Antonio, Portland, W.I, Jamaica, 2The Henry P. Becton School of Nursing

& Allied Health, Fairleigh Dickinson University, Teaneck, NJ 07666, 3College of Agriculture & Related Sciences, Delaware State University, Dover, DE 19901

Introduction

In recent years, there has been increased interest in plants

that produce functional (health impacts) fatty acids [1]. Njangsa

(Ricinodendron heudelotti) seed oil is unusually rich in

polyunsaturated fatty acid (PUFA), which account for about 75%

of the total fatty acids [2]. Njangsa is native to Central and

West Africa. Njangsa seed with commercial levels of oil and

PUFA would have potential as a high-value oil crop. Several

conventional and emerging methods are available for oil

extraction [3, 4]. However, the choice of method is often dictated

by time, cost, and safety of the method and the yield and quality

of oil extracted. To increase the industrial application and

utilization of oil from Njangsa seed, extraction methods that

result in high yields without compromising the quality of the

extracted oil are required. The objectives of this study were to:

1) evaluate the extraction of oil from Njangsa seed using three

methods, and 2) determine the quality of the oil extracted.

Materials and Methods

Njangsa seeds were obtained from a local African store in

Smyrna, DE. All reagents were purchased from Sigma-Aldrich

(St. Louis, MO).

Gravimetric Analysis

𝐎𝐢𝐥 𝐘𝐢𝐞𝐥𝐝 (%) = wgt of oil

wgt of ground seed 𝑥 100%

Quality Parameters: Free fatty acid (FFA) content, peroxide

value (PV) and thiobarbituric acid (TBA) value of the oil were

determined according to Ca 5a-40, Cd 8-53 and Cd 19-90,

respectively of the Official Methods of the American Oil

Chemists’ Society (AOCS) [6], to asses the effect of extraction

methods on oil quality.

Acknowledgements

This study was made possible by the National Science Foundation EPSCoR Grant No. IIA-

1301765, the State of Delaware, and enzyme donation from Enzyme Development Corporation

(New York City, NY).

References [1]. Ezekwe et al. (2014). Nutritive composition of omega-3 fatty acids-rich Ricinodendron heudelotii and its potential for nutrition. Int. J. Nutr. Metab.

6(6): 56-62.

[2]. Manga et al. (2000). Chemical composition of Ricinodendron heudelotii: An indigenous fruit tree in southern Cameroon. Afr. Crop Sci. J. 8: 195-

201.

[3]. Aryee, A.N.A. and Simpson, B.K. (2009). Comparative studies on the yield and quality of solvent-extracted oil from salmon skin. J. Food Eng.

92(3): 353-358.

[4]. Gayas, B. and Gagandeep, K. (2017). Novel oil extraction methods in food industry: A review. Journal of Oilseed Brassica, 8(1): 1-11.

[5]. Folch et al. (1957). A simple method for the isolation and purification of total lipides from animal tissues. J. Biol. Chem. 226: 497-509.

[6]. AOCS (2004). Official Methods and Recommended Practices. Method Additions and Revisions.

Abstract The time, cost, safety, and quality of oil, of an oil extraction method are important selection criteria in the oil industry. A detailed investigation of the relationship between

extraction methods and product quality is therefore necessary. In this study, the extraction of oil from Njangsa (Ricinodendron heudelotti) seed was evaluated using three

methods; the classical Folch method (FM), hexane extraction (HE), and enzyme-assisted extraction (EAE), and their influence on the recovery and quality of oil was

determined by gravimetric analysis, free fatty acid (FFA) content, peroxide value (PV) and thiobarbituric acid (TBA) value assays. There were significant (P>0.05) differences

between the extraction methods. The content of FFA and formation of peroxides were dependent on the extraction method, and the lowest TBA value was obtained by EAE.

Conclusion

Both the hexane and enzyme-assisted extraction (EAE) methods afforded simple extraction

processes and recovery, whilst the Folch method was laborious and time-consuming. EAE

and chloroform-methanol extraction (Folch method) recovered similar amount of oil, however

the yields of these two methods were lower than hexane extraction (HE). Nonetheless, there

was no exposure to toxic and potentially carcinogenic solvents in the EAE method. The

quality of oil produced by the EAE method was found to be comparable or even superior to

that obtained from the FM and HE methods, further demonstrating the viability of enzyme-

assisted extraction.

Determination of peroxide value by titration Determination of thiobarbituric acid value spectrophotometrically

Results & Discussions The yield of Njangsa seed oil from the FM,

HE, and EAE methods were: 19.99, 53.22

and 15.07%, respectively (Fig. 2). The result

suggest that oil yield is dependent on the

method of extraction.

Both the Folch and hexane extraction

methods produced oils with higher PV (10 -

20 mEq/kg oil)compared to the EAE method

(Fig. 2).

The TBA values of the oil extracted by the

HE and FM were both 0.13 mg of

malonaldehyde/kg oil. This is more than 4-

fold higher than the TBA value from the EAE

method (0.03 mg of malonaldehyde/kg oil)

(Fig. 2). This indicates that there was

comparably lower secondary oxidation

during EAE.

15.07

19.99

53.22

1.99

1.99

1.99

9.80

10.00

19.84

0 10 20 30 40 50 60

Hemicellulase 20M - Enzyme extraction(EAE)

Chloroform-Methanol - Folch method (FM)

Hexane extraction (HE)

Values

Ex

trac

tio

n m

eth

od

s

TBA (mg of malonaldehyde/kg ofoil)

PV (5 mEq of peroxides/kg of oil)

FFA (0-3.30%)

Oil Yield

Fig. 2: Comparison of oil extraction methods and oil quality

Fig. 1: A schematic representation of the extraction methods