Page Header

A Review on the Physicochemical Properties of γ-irradiated Copra (Dried Cocos nucifera L.)

Michael John L. De Mesa, Flordeliza C. De Vera


Copra or dried coconut kernel is a primary product of coconut and is known to be a source of coconut oil. It is found to be highly susceptible to Aspergillus flavus that can cause aflatoxin contamination during pre- and post-harvesting processes. Therefore, researchers have been looking for a method to reduce aflatoxins in copra to a safe level while positively affecting its properties. The γ-irradiation is found to induce growth inhibition of A. flavus in copra at low irradiation doses (0 to 3 kGy) using a semi-commercial irradiator. This result is supported by other food samples having a high reduction of aflatoxins. Currently, no studies examined the influence of γ-irradiation on the physicochemical properties of copra. Hence, this study used the properties of different γ-irradiated commodities that are similar to copra to justify the need of investigating properties in irradiated copra. Gamma irradiation has the potential to increase the fat and ash content, decrease protein and crude fiber content at higher absorbed doses, and expected no changes in moisture content of the irradiated copra. In addition to this, the effect of the irradiation on carbohydrate content, phytochemical profile, and water activity may vary in significant findings until further investigations have been made on irradiated copra. However, the researchers recommended that the microbial activity of A. flavus and characterization of the physicochemical properties of irradiated copra were necessary for future experimentations.


[1] Coconut Handbook, Tetra Pak International, Singapore, 2016.

[2] Allied Market Research, “Coconut products market,” 2019. [Online]. Available: https://www. market.html

[3] Y. T. Agustin, “Global competitiveness, benchmarking and best practices for the coconut industry,” University of Asia and the Pacific, Mar. 2005.

[4] J. Faustino, Facing the Challenges of the Philippine Coconut Industry: The Lifeblood of 3.4 Million Coconut Farmers and Farm Workers. Philippine: Coconut Industry Reform Movement, 2006.

[5] M. L. Moreno, J. K. M. Kuwornu, and S. Szabo, “Overview and constraints of the coconut supply chain in the Philippines,” International Journal of Fruit Science, vol. 20, pp. 524–541, 2020, doi: 10.1080/15538362.2020.1746727.

[6] P. Appaiah, L. Sunil, P. K. P. Kumar, and A. G. G. Krishna, “Composition of coconut testa, coconut kernel and its oil,” Journal of the American Oil Chemists' Society, vol. 91, pp. 917– 924, 2014, doi: 10.1007/s11746-014-2447-9.

[7] D. Kumar and P. Kalita, “Reducing postharvest losses during storage of grain crops to strengthen food security in developing countries,” Foods, vol. 6, pp. 1–22, 2017, doi: 10.3390/foods6010008.

[8] T. Fernandes, J. Ferrão, V. Bell, and I. Chabite, “Mycotoxins, food and health,” Journal of Nutritional Health & Food Science, vol. 5 pp. 1–10, 2017, doi: 10.15226/jnhfs.2017.001118.

[9] S. K. Pankaj, H. Shi, and K. M. Keener, “A review of novel physical and chemical decontamination technologies for aflatoxin in food,” Trends in Food Science & Technology, vol. 71, pp. 73–83, 2018, doi: 10.1016/j.tifs.2017.11.007.

[10] R. J. S. Leger, S. E. Screen, and B. Shams-Pirzadeh, “Lack of host specialization in Aspergillus flavus,” Applied and Environmental Microbiology, vol. 66, pp. 320–324, 2000, doi: 10.1128/AEM. 66.1.320-324.2000.

[11] S. A. Jackson and A. D. W. Dobson, “Yeasts and molds: Aspergillus flavus,” in Reference Module in Food Science. Amsterdam, Netherlands: Elsevier, 2016, doi: 10.1016/b978-0-08-100596- 5.01086-6.

[12] IARC Working Group, “Chemical agents and related occupations,” in IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, No. 100F. Lyon, France: International Agency for Research on Cancer, 2012.

[13] WHO, WHO Estimates of the Global Burden of Foodborne Diseases. WHO, Switzerland, 2015.

[14] FAO, “Worldwide regulations for mycotoxins in food and feed in 2003,” 2004. [Online]. Available: c/3c32b78f-9fc9-5b78-8e43-0a82a7bd772b/

[15] E. Assunção, T. A. Reis, A. C. Baquião, and B. Corrêa, “Effects of gamma and electron beam radiation on Brazil nuts artificially inoculated with Aspergillus flavus,” Journal of Food Protection, vol. 78, pp. 1397–1401, 2015, doi: 10.4315/0362-028X.JFP-14-595.

[16] P. Y. Inamura, V. B. Uehara, C. A. H. M. Teixeira, and N. L. D. Mastro, “Mediate gamma radiation effects on some packaged food items,” Radiation Physics and Chemistry, vol. 81, pp. 1144–1146, 2012, doi: 10.1016/j.radphyschem.2012.01.022.

[17] D. L. de Asis, R. B. Tumlos, and G. I. S. Su, “Gamma irradiation for the inactivation of Aspergillus flavus link in copra (Dried Cocos nucifera L. meat),” Philippine Journal of Science, vol. 149, pp. 113–116, 2020.

[18] S. Aquino, F. Ferreira, D. H. B. Ribeiro, B. Corrêa, R. Greiner, and A. L. C. H. Villavicencio, “Evaluation of viability of Aspergillus flavus and aflatoxins degradation in irradiated samples of maize,” Brazilian Journal of Microbiology, vol. 36, pp. 352–356, 2005, doi: 10.1590/S1517-83822 005000400009.

[19] M. Makari, M. Hojjati, S. Shahbazi, and H. Askari, “Effect of Co-60 gamma irradiation on Aspergillus flavus, Aflatoxin B1 and qualitative characteristics of pistachio nuts (Pistacia vera L.),” Journal of Food Measurement and Characterization, vol. 15, pp. 5256–5265, 2021, doi: 10.1007/s11694-021- 01060-z.

[20] K. Markov, B. Mihaljević, A. M. Domijan, J. Pleadin, F. Delaš, and J. Frece, “Inactivation of aflatoxigenic fungi and the reduction of aflatoxin B1 invitro and in situ using gamma irradiation,” Food Control, vol. 54, pp. 79–85, 2015, doi: 10.1016/j.foodcont.2015.01.036.

[21] T. Calado, A. Venâncio, and L. Abrunhosa, “Irradiation for mold and mycotoxin control: A review,” Comprehensive Reviews in Food Science and Food Safety, vol. 13, pp. 1049–1061, 2014, doi: 0.1111/1541-4337.12095.

[22] L. R. Stone, D. R. Gray, K. Remple, and M. P. Beaudet, “Accuracy and precision comparison of the hemocytometer and automated cell counting methods,” The FASEB Journal, vol. 23, no. S1, pp. 827–827, 2009, doi: 10.1096/fasebj.23.1_ supplement.827.2.

[23] M. S. Serra, M. B. Pulles, F. T. Mayanquer, M. C. Vallejo, M. I. Rosero, J. M. Ortega, and L. N. Naranjo, “Evaluation of the use of gamma radiation for reduction of aflatoxin B1 in Corn (Zea mays) used in the production of feed for broiler chickens,” Journal of Agricultural Chemistry and Environment, vol. 7, no. 1, pp. 21–33, 2018, doi: 10.4236/jacen.2018.71003.

[24] M. A. Swelim, “Effect of gamma radiation on the inactivation of aflatoxin B1 in food and feed crops,” Brazilian Journal of Microbiology, vol. 39, no. 4, pp. 787–791, 2008.

[25] Y. Guo, L. Zhao, Q. Ma, and C. Ji, “Novel strategies for degradation of aflatoxins in food and feed: A review,” Food Research International, vol. 140, 2021, doi: 10.1016/j. foodres.2020.109878.

[26] A. M. Domijan, A. M. Marjanović Čermak, A. Vulić, I. Tartaro Bujak, I. Pavičić, J. Pleadin, K. Markov, and B. Mihaljević, “Cytotoxicity of gamma irradiated aflatoxin B1 and ochratoxin A,” Journal of Environmental Science and Health, vol. 54, pp. 155–162, 2019, doi: 10.1080/03601234.2018.1536578.

[27] M. Jalili, “A review on aflatoxins reduction in food,” Iranian Journal of Health, Safety and Environent, vol. 3, pp. 445–459, 2015.

[28] K. Liu, Y. Liu, and F. Chen, “Effect of gamma irradiation on the physicochemical properties and nutrient contents of peanut,” LWT - Food Science and Technology, vol. 96 pp. 535–542, 2018, doi: 10.1016/j.lwt.2018.06.009.

[29] P. K. Ghosh, P. Bhattacharjee, S. Mitra, and M. Poddar-Sarkar, “Physicochemical and phytochemical analyses of copra and oil of Cocos nucifera L. (West coast tall variety),” International Journal of Food Science, vol. 2014, 2014, doi: 10.1155/2014/310852.

[30] E. O. Okene and B. Evbuomwan, “Solvent extraction and characterization of oil from coconut seed using alternative solvents,” International Journal of Engineering and Technical Research, vol. 2, pp. 135–138, 2014.

[31] Q. U. Khan, I. Mohammadzai, Z. Shah, I. Ullah, T. N. Khattak, H. Noreen, and W. Hassan, “Effect of gamma irradiation on nutrients and shelf life of peach (Prunus persical) stored at ambient temperature,” The Open Conference Proceedings Journal, vol. 9, pp. 8–15, 2018, doi: 10.2174/2210289201809010008.

[32] O. P. Bamidele and C. T. Akanbi, “Effect of gamma irradiation on physicochemical properties of stored pigeon pea (Cajanus cajan) flour,” Food Science and Nutrition, vol. 1, pp. 377– 383, 2013, doi: 10.1002/fsn3.50.

[33] M. M. Anwar, S. E. Ali, and E. H. Nasr, “Improving the nutritional value of canola seed by gamma irradiation,” Journal of Radiation Research and Applied Sciences, vol. 8, pp. 328–333, 2015, doi: 10.1016/j.jrras.2015.05.007.

[34] S. Chumwaengwapeea, S. Soontornchaia, and K. Thongprajukeawb, “Improving chemical composition, physicochemical properties, and in vitro carbohydrate digestibility of fish coconut meal,” ScienceAsia, vol. 39, pp. 636–642, 2013, doi:10.2306/scienceasia1513-1874.2013.39.636.

[35] Y. J. Chen, G. H. Zhou, X. D. Zhu, X. L. Xu, X. Y. Tang, and F. Gao, “Effect of low dose gamma irradiation on beef quality and fatty acid composition of beef intramuscular lipid,” Meat Science, vol. 75, pp. 423–431, 2007, doi: 10.1016/j.meatsci.2006.08.014.

[36] X. Fan and S. E. Kays, “Formation of trans fatty acids in ground beef and frankfurters due to irradiation,” Journal of Food Science, vol. 74 pp. 79–84, 2009, doi: 10.1111/j.1750- 3841.2008.01024.x.

[37] R. S. Orozco, P. B. Hernández, N. F. Ramírez, G. R. Morales, J. S. Luna, and A. J. C. Montoya, “Gamma irradiation induced degradation of orange peels,” Energies, vol. 5, pp. 3051–3063, 2012, doi: 10.3390/en5083051.

[38] E. H. Byun, J. H. Kim, N. Y. Sung, J. Choi, S. T. Lim, K. H. Kim, H. S. Yook, M. W. Byun, and J. W. Lee, “Effects of gamma irradiation on the physical and structural properties of β-glucan,” Radiation Physics and Chemistry, vol. 77, no. 6, pp. 781–786, 2008, doi: 10.1016/j.radphyschem. 2007.12.008.

[39] O. A. Gaston, N. S. Daniel, and N. O. Arnold, “Physico-chemical properties of kernel from coconut (Cocos nucifera L.) varieties grown at the Kenyan Coast,” African Journal of Food Science, vol. 15, pp. 313–321, 2021, doi: 10.5897/ajfs2021.2116.

[40] F. Akuamoa, G. T. Odamtten, and N. K. Kortei, “Nutritional and shelf-life studies of dry smoked and gamma irradiated shrimps (Penaeus notialis) from three different water sources in Ghana,” Cogent Food & Agriculture, vol. 4, pp. 1–9, 2018, doi: 10.1080/23311932.2018.1505803.
[41] A. A. M. Nour, S. E. A. Hmed, and G. A. M. Osman, “Effect of gamma irradiation on the physicochemical characterstics of groundnut (Arachis Hypogaea),” Australian Journal of Basic and Applied Sciences, vol. 3, pp. 2856–2860, 2009.

[42] L. F. Costa, E. Borges da Silva, and I. S. D. Oliveira, “Influence of gamma radiation on the nutrition composition and contamination by Aflatoxigenic Aspergillus on Peanuts,” presented at the 2011 International Nuclear Atlantic Conference, MG, Brazil, Oct. 24-28, 2011.

[43] N. X. B. Nguyen, A. Uthairatanakij, N. Laohakunjit, P. Jitareerat, C. Rattanakreetakul, K. Boonsirichai, and N. Kaisangsri, “Oil characterization and aflatoxin profile of peanut kernel subjected to gamma irradiation,” International Journal of Food Engineering, vol. 6, pp. 1–5, 2020, doi: 10.18178/ijfe.6.1.1-5.

[44] U. M. Odenigbo and C. A. O. Otisi, “Fatty acids and phytochemical contents of different coconut seed flesh in Nigeria,” International Journal of Plant Physiology and Biochemistry, vol. 3, pp. 176–182, 2011.

[45] M. A. Abdelaleem and K. R. A. Elbassiony, “Evaluation of phytochemicals and antioxidant activity of gamma irradiated quinoa (Chenopodium quinoa),” Brazilian Journal of Biology, vol. 81, pp. 806–813, 2021, doi: 10.1590/1519-6984. 232270.

[46] K. S. Moosavi, S. Hosseini, G. Dehghan, and A. Jahanban-Esfahlan, “The effect of gamma irradiation on phytochemical content and antioxidant activity of stored and none stored almond (Amygdalus communis L.) hull,” Pharmaceutical Sciences, vol. 20, pp. 102–106, 2014.

[47] R. Bhat, K. R. Sridhar, and K. Tomita-Yokotani, “Effect of ionizing radiation on antinutritional features of velvet bean seeds (Mucuna pruriens),” Food Chemistry, vol. 103, no. 3, pp. 860–866, 2007, doi: 10.1016/j.foodchem.2006.09.037.

[48] K. F. Khattak, T. J. Simpson, and Ihasnullah, “Effect of gamma irradiation on the extraction yield, total phenolic content and free radical-scavenging activity of Nigella staiva seed,” Food Chemistry, vol. 110, no. 4, pp. 967–972, 2008, doi: 10.1016/ j.foodchem.2008.03.003.

[49] Obidoa, P. E. Joshua, Onyechi, and N. J. Eze, “Phytochemical analysis of Cocos nucifera L.,” Journal of Pharmacy Research, vol. 1, no.1, pp. 87–96, 2009.

[50] D. Štajner, M. Milošević, and B. M. Popović, “Irradiation effects on phenolic content, lipid and protein oxidation and scavenger ability of soybean seeds,” International Journal of Molecular Sciences, vol. 8, pp. 618–627, 2007, doi: 10.3390/ i8070618.

[51] K. Harrison and L. M. Were, “Effect of gamma irradiation on total phenolic content yield and antioxidant capacity of Almond skin extracts,” Food Chemistry, vol. 102, pp. 932–937, 2007, doi: 10.1016/j.foodchem.2006.06.034.

[52] M. Behgar, S. Ghasemi, A. Naserian, A. Borzoie, and H. Fatollahi, “Gamma radiation effects on phenolics, antioxidants activity and in vitro digestion of pistachio (Pistachia vera) hull,” Radiation Physics and Chemistry, vol. 80, pp. 963–967 2011, doi: 10.1016/j.radphyschem. 2011.04.016.

[53] M. Vera Zambrano, B. Dutta, D. G. Mercer, H. L. MacLean, and M. F. Touchie, “Assessment of moisture content measurement methods of dried food products in small-scale operations in developing countries: A review,” Trends in Food Science & Technology, vol. 88, pp. 484–496, 2019, doi: 10.1016/j.tifs.2019.04.006.

[54] C. Kavitha, A. Kuna, T. Supraja, S. B. Sagar, T. V. N. Padmavathi, and N. Prabhakar, “Effect of gamma irradiation on antioxidant properties of ber (Zizyphus mauritiana) fruit,” Journal of Food Science and Technology, vol. 52, pp. 3123–3128, 2015, doi: 10.1007/s13197-014-1359-x.

[55] M. Suhaj, J. Rácová, M. Polovka, and V. Brezová, “Effect of γ-irradiation on antioxidant activity of black pepper (Piper nigrum L.),” Food Chemistry, vol. 97, pp. 696–704, 2006, doi: 10.1016/ chem.2005.05.048.

[56] M. Suhaj and J. Horváthová, “Changes in antioxidant activity induced by irradiation of clove (Syzygium aromaticum) and ginger (Zingiber officinale),” Journal of Food and Nutrition Research, vol. 46, pp. 112–122, 2007.

[57] L. Boateng, R. Ansong, W. B. Owusu, and M. Steiner-Asiedu, “Coconut oil and palm oil’s role in nutrition, health and national development: A review,” Ghana Medical Journal, vol. 50, pp. 189–196, 2016, doi: 10.4314/gmj.v50i3.11.

[58] L. M. Browning, C. G. Walker, A. P. Mander, A. L. West, J. Madden, J. M. Gambell, S. Young, L. Wang, S. A. Jebb, and P. C. Calder, “Incorporation of eicosapentaenoic and docosahexaenoic acids into lipid pools when given as supplements providing doses equivalent to typical intakes of oily fish,” The American Journal of Clinical Nutrition, vol. 96, no. 4, pp. 748–758, 2012, doi: 10.3945/ajcn.112.041343.

[59] J. Cao, K. A. Schwichtenberg, N. Q. Hanson, and M. Y. Tsai, “Incorporation and clearance of omega-3 fatty acids in erythrocyte membranes and plasma phospholipids,” Clinical Chemistry, vol. 52, pp. 2265–2272, 2006, doi: 10.1373/ clinchem.2006.072322.

[60] I. Minami, Y. Nakamura, S. Todoriki, and Y. Murata, “Effect of γ irradiation on the fatty acid composition of soybean and soybean oil,” Bioscience, Biotechnology, and Biochemistry, vol. 76, no. 5, pp. 900–905, 2012, doi: 10.1271/ bbb.110859.

[61] J. O. Idowu, A. D. Oyinade, S. B. Funminiyi, and E. O. Gbenga, “Antioxidants and radical scavenging activities of nigerian soybeans (Glycine max (L.) Merr.),” European Journal of Medicinal Plants, vol. 27, no.1, pp. 1–8, 2019, doi: 10.9734/ ejmp/2019/v27i130104.

[62] S. F. Mexis and M. G. Kontominas, “Effect of γ-irradiation on the physicochemical and sensory properties of cashew nuts (Anacardium occidentale L.),” LWT - Food Science and Technology, vol. 42, no. 9, pp. 1501–1507, 2009, doi: 10.1016/j.lwt.2009.03.023.

[63] U. Gecgel, T. Gumus, M. Tasan, O. Daglioglu, and M. Arici, “Determination of fatty acid composition of γ-irradiated hazelnuts, walnuts, almonds, and pistachios,” Radiation Physics and Chemistry, vol. 80, no. 4, pp. 578–581, 2011, doi: 10.1016/j.radphyschem.2010.12.004.

[64] V. J. Sinanoglou, I. F. Strati, K. Kokkotou, D. Lantzouraki, C. Makris, and P. Zoumpoulakis, “GC-FID and NMR spectroscopic studies on gamma irradiated walnut lipids,” Journal of Spectroscopy, vol. 2015, 2015, Art. no. 532762, doi: 10.1155/2015/532762.

[65] N. Balakrishnan, S. M. Yusop, I. A. Rahman, E. Dauqan, and A. Abdullah, “Efficacy of gamma irradiation in improving the microbial and physical quality properties of dried chillies (Capsicum annuum L.): A Review,” Foods, vol. 11, no. 1, pp. 1–18, 2022, doi: 10.3390/foods11010091.

[66] S. Koç Güler, S. Z. Bostan, and A. H. Çon, “Effects of gamma irradiation on chemical and sensory characteristics of natural hazelnut kernels,” Postharvest Biology and Technology, vol. 123, pp. 12–21, 2017, doi: 10.1016/j. postharvbio.2016.08.007.

[67] M. Al-Bachir, “Effect of gamma irradiation on fungal load, chemical and sensory characteristics of walnuts (Juglans regia L.),” Journal of Stored Products Research, vol. 40, no. 4, pp. 355–362, 2004, doi: 10.1016/S0022-474X(03)00030-4.

[68] M. Al-Bachir, “Evaluation the effect of gamma irradiation on microbial, chemical and sensorial properties of peanut (Arachis hypogaea L.) seeds,” Acta Scientiarum Polonorum Technologia Alimentaria, vol. 15, no. 2, pp. 171–179, 2016, doi: 10.17306/J.AFS.2016.2.17.

[69] S. Seed, R. Akinoso, and J. C. Igbeka, “Process optimization of oil expression from sesame seed (Sesamum indicum Linn.),” Agricultural Engineering International: The CIGR Ejournal, vol. 8, pp. 1–7, 2006.

[70] A. C. D. Camargo, T. M. F. D. S. Vieira, M. A. B. Regitano-d’Arce, S. M. D. Alencar, M. A. Calori-Domingues, M. H. F. Spoto, and S. G. Canniatti-Brazaca, “Gamma irradiation of in-shell and blanched peanuts protects against mycotoxic fungi and retains their nutraceutical components during long-term storage,” International Journal of Molecular Sciences, vol. 13, no. 9, pp. 10935–10958, 2012, doi: 10.3390/ijms130910935.

[71] A. Yadav, B. Singh, D. K. Sharma, and S. Ahuja, “Effects of gamma irradiation on germination and physiological parameters of maize (Zea mays) genotypes,” Indian Journal of Agricultural Sciences, vol. 85, no. 9, pp. 1148–1152, 2015.

Full Text: PDF

DOI: 10.14416/j.asep.2022.08.003


  • There are currently no refbacks.