Application of coconut fiber and shell in the bleaching of soybean oil




Adsorbents, Agricultural waste, Bleaching, Coconut, Soybean oil


The bleaching process is an important stage in the edible oil refining operation, and is carried out by using acid-activated bleaching earths. The aim of this study was to evaluate the efficiency of coconut fiber ash, shell ash, acid-activated fiber ash and acid-activated shell ash as compared to the commercial bleaching earth in the bleaching of neutralized soybean oil. Bleaching materials were added to neutralized oil at the concentration of 1% (w/v) with agitation under vacuum at 110 °C for 30 minutes. The values for red and yellow colors, carotenoids, chlorophylls, peroxide value, p-anisidine value, free fatty acid contents, copper and iron levels of the bleached samples were determined. The results indicated that all coconut-based adsorbents have been significantly more effective than commercial bleaching earth in reducing color and the greatest reductions in carotenoid (84.25%) and chlorophyll (82.30%) contents were obtained by using acid-activated fiber ash. The peroxide value for all treatments decreased. The amounts of iron and copper as peroxide compounds decreased considerably (44.59% and 23.53%) by using acid-activated fiber ash and acid-activated shell ash, respectively. Therefore, coconut fiber and shell as agricultural wastes which have been ignored in the past might be employed as effective agents to bleach crude oils, particularly soybean oil, in refining operations.


Download data is not yet available.


Abdi E, Gharachorloo M, Ghavami M. 2021. Investigation of using egg shell powder for bleaching of soybean oil. LWT-Food Sci. Technol. 140, 110859.

Almasi A, Mousavi SA, Hesari A, Janjani H. 2016. Walnut shell as a natural adsorbent for the removal of Reactive Red 2 form aqueous solution. Intl. Res. J. Appl. Basic. Sci. 10, 551-556.

AOCS. 2003. Declared surplus peroxide value-acetic acid-chloroform method.

AOCS. 2009. Official Method Cc 13e-92. Color Fats Lovibond.

AOCS. 2017a. Official Method Cc 13d-55. Chlorophyll pigments in Refined and Bleached Oils.

AOCS. 2017b. Official Method C 3d-63. Acid value fats and oils.

AOCS. 2017c. Official Method Cd 15-75. Analyses for chromium, copper, iron, and nickel in vegetable oils by atomic absorption spectrophotometry.

Aarti Sowmya T, Gayavajitha E, Kanimozhi R, Subalakshmi R. 2018. Removal of toxic metals from industrial wastewater using Groundnut shell. Int. J. Pure Appl. Math. 119, 629-634.

Boki K, Kubo M, Wada T, Tamura T. 1992. Bleaching of alkali-refined vegetable oils with clay minerals. J. Am. Oil Chem. Soc. 69, 232-236.

BS 684. 1993. Fats and fatty oils- Determination of carotene in vegetable oils.

Diosady LL. 2005. Chlorophyll Removal from Edible oils. Int. J. Appl. Sci. Eng. 3, 81-88.

El-Hamidi M, Zaher FA. 2016. Comparison Between Some Common Clays as Adsorbents of Carotenoids, Chlorophyll and Phenolic Compounds from Vegetable Oils. Am. J. Food Technol. 11, 92-99.

Emojevwe V. 2013. Cocos nucifera (Coconut) Fruit: A review of its medical properties. Adv. Agr. Sci. Eng. Res. 3, 718-723.

Erten Y. 2004. Use of domestic minerals for vegetable oil blanching. Master ASTER of Science Food Engineering. İzmir Institute of Technology izmir, Turkey.

Forozan Sepehr Z, Gharachorloo M, Yousefi S. 2020. Investigation of soybean oil bleaching by using walnut shell. J. Nuts, 11, 169-177.

Hambly AJ, van Duijneveldt JS, Gates PJ. 2021. Identification of β-carotene oxidation products produced by bleaching clay using UPLC-ESI-MS/MS. Food Chem. 353, 129455.

Hussin F, Aroua MK, Wan Daud WMA. 2011. Textural characteristics, surface chemistry and activation of bleaching earth: A review. Chem. Eng. J. 170, 90-106.

ISO 6885. 2006. Animal and vegetable fats and oils - determination of anisidine value, ISO method 6885:2006, geneva, Switzerland.

Ikumapayi OM, Akinlabi ET, Majumdar JD, Akinlabi SA. 2020. Applications of coconut shell ash/particles in modern manufacturing: a case study of friction stir processing. Mod. Manuf. Process. 69-95.

Johari K, Saman N, Song ST, Heng JYY, Mat H. 2014. Study of Hg(II) removal from aqueous solution using lignocellulosic coconut fiber biosorbents: Equilibrium andkinetic evaluation. Chem. Eng. Commun. 201, 1198-1220.

Jung MY, Yoon SH, Min DB. 1989. Effects of processing steps on the contents of minor compounds and oxidation of soybean oil. J. Am. Oil Chem. Soc. 66, 118-120.

Junmao T, Zhansheng W, Xifang S, Xiaolin X, Chun L. 2008. Adsorption Kinetics of β- carotene and Chlorophyll an Acid- activation Bentonite in Model oil. Chin. J. Chem. Eng. 16 (2), 270-276.

Kashani Motlagh MM, Youzbashi AA, Amiri Rigi Z. 2011. Effect of acid activation on structural and bleaching properties of a bentonite. Iran. J. Mater. Sci. Eng. 8, 50-56.

Martins AP, Sanches RA. 2019. Assessment of coconut fibers for textile applications. Revista Matéria. 24.

Mirrezaie Roodaki MS, Sahari MA, Ghiassi Tarzi B, Barzegar M, Gharachorloo M. 2016. Effect of refining and thermal processes on olive oil properties. J. Agric. Sci. Technol. 18, 629-641.

Mustapha SI, Mohammed AA, Zakari AY, Mohammed HA. 2013. Performance evaluation of local clays from northern Nigeria for the refining of palm oil. J. Chem. Eng. Mater. Sci. 4, 58-66.

Pauline DP. 2000. Dictionary of plants used in Cambodia. Imprimerie Olympic. pp. 165-166.

Shruthi KM, Pavithra MP. 2018. A study on utilization of groundnut shell as biosorbent for heavy metals removal. Int. J. Eng. Tech. 4, 411-415.

Silva SM, Sampaio KA, Ceriani R, Verhé R, Stevens C, Greyt WD, Meirelles AJA. 2014. Effect of type of bleaching earth on thefinal color of refined palm oil. LWT - Food Sci. Technol. 59, 1258-1264.

Subramanian R, Nabetani H, Nakajima M, Ichikawa S, Kimura T, Maekawa T. 2001. Rejection of Carotenoids in Oil Systems by a Nonporous Polymeric Composite Membrane. J. Am. Oil Chem. Soc. 78, 803-807.

Taksitta K, Sujarit P, Ratanawimarnwong N, Donpudsa S, Songsrirote K. 2020. Development of tannin-immobilized cellulose fiber extracted from coconut husk and the application as a biosorbent to remove heavy metal ions. Environ. Nanotechnol. Monit. Manag. 14, 100389.

Usman MA, Ekwueme VI, Alaje TO, Mohammed AO. 2012. Characterization, acid activation, and bleaching performance of Ibeshe clay, Lagos, Nigeria. ISRN Ceramics, 1-5.

Yuan J, Zhu Y, Wang J, Gan L, He M, Zhang T, Li P, Qiu F. 2021. Preparation and application of Mg-Al composite oxide/coconut shell carbon fiber for effective removal of phosphorus from domestic sewage. Food Bioprod. Process. 126, 293-304.

Zeb A, Murkovic M. 2011. Carotenoids and triacylglycerols interactions during thermal oxidation of refined olive oil. Food Chem. 127, 1584-1593.

Zeb A, Murkovic M. 2013. Determination of thermal oxidation and oxidation products of β-carotene in corn oil triacylglycerols. Food Res. Int. 50, 534-544.

Zheng R, Gao H, Ren Z, Cen D, Chen Z. 2017. Preparation of activated bentonite and its adsorption behaviour on oil-soluble green pigment. Physicochem. Probl. Miner. Process. 53, 829−845.



How to Cite

Tavakoli Ghahjaverestani S, Gharachorloo M, Ghavami M. Application of coconut fiber and shell in the bleaching of soybean oil. grasasaceites [Internet]. 2022Sep.8 [cited 2022Sep.29];73(3):e471. Available from: