Abstract
A broad variety of fungi (84 species belonging to 36 genera) were identified with more taxa infesting peanut seed samples from two tropical countries (29 genera and 61 species) compared to those found in desiccated coconuts (20 genera and55 species) on both DRBC and DG18 media. This may be due to the higher moisture levels in peanuts (5.07–7.97%) compared with coconuts (1.5–4.17%). More taxa and propagules were recovered on DG18 in both cases. The dominant fungi from both substrates on both isolation media were Aspergillus andPenicillium, with other fungi from only one substrate/medium. The aflatoxigenic species (A. flavus) dominated Kenyan samples more so than Ugandan samples on both substrates. However only71.5% and 87% of the peanut kernels, on DRBC and DG18, respectively, were found to be infested with fungi. The aflatoxigenic species (A. flavus/parasiticus)were found in 75% of the samples, however only 15.75% and 13%of the kernels analyzed were infested. The most frequently isolated species from peanuts were A. niger followed by A. flavus and M. phaseolina. E. repens, E. amstelodami,E. rubrum and E. chevalieri dominated peanut seeds on DG18, and R. stolonifer, A. parasiticus,F. solani, L. theobromae and P. chrysogenumon DRBC. The mean count of fungal propagules in coconut samples were approximately 0.7× 103 and 0.8× 103on DRBC and DG18, respectively, with a high proportion of those propagules recorded for the aflatoxigenic species (about 0.17×103 and 0.25× 103 colonies/g). The mycobiota of desiccated coconut was dominated by A. niger, A. flavusand P. chrysogenum. Also A. ochraceu,P. waksmanii, Paecilomyces variotii,P. islandicum and R. mucilaginosa were more frequent on DRBC, while, species of Cladosporium,Chrysosporium and Eurotium were more frequent on DG18.
Enzyme indices (or the activities) for each specific strain, when determined after 5 and 8 days of incubation, proved to be similar. A recommendation is given. The proteolytic and lipolytic potentialities of the most commonly encountered species from both peanuts and coconuts were studied. The most interesting observation is that most of the positive isolates, in both commodities had high enzymic activity compared to those reported earlier for isolates of the same species. Such capabilities suggest that these commodities are expected to deteriorate, since climatic conditions in tropical areas favour fungal proliferation. Emphasis on the proper harvesting, drying, handling, transportation and/or storage; and also education of the populace, especially those are dealing with these foods, should be taken into consideration by the relevant authorities. The contaminated foods constitute a health hazard for human consumption.
Similar content being viewed by others
References
FAO Recommended practices for the prevention of mycotoxins in food, feed and their products. FAO Food and Nutrition Paper No.10: Food and Agriculture Organization of the United Nations, Rome 1979. 71 pp.
Bullerman LB. Significance of mycotoxins to food safety and human health. J Food Prot 1979; 42: 65-86.
Rustom IYS. Aflatoxin in food and feed-occurrence, legislation and inactivation by physical methods. Food Chemistry 1997; 59(1): 57-67.
Lopez A, Crawford MA. Aflatoxin content of peanuts sold for human consumption in Uganda. Lancet 1967; 2: 1351-1354.
Alpert ME, Hutt MSR, Wogan GN, Davidson CS. Association between aflatoxin content of food and hepatoma frequency in Uganda. Cancer 1971; 28: 253-260.
Sebunya TK, Yourtee DM. Aflatoxigenic aspergilli in foods and feeds in Uganda. Journal of Food Quality 1990; 13: 97-107.
Peers FG, Linsell T. Dietary aflatoxins and liver cancer. A population based study in Kenya. Br J Cancer 1973; 27: 473-484.
Muriuki G. Studies on mycoflora of stored maize and maize products: Their enumeration and significance. M.Sc. Thesis, College of Biological and Physical Sciences, Faculty of Science, Department of Botany, University of Nairobi, 1992.
Mirocha CJ. Historical aspects of mycotoxicology and developments in aflatoxicosis. Proc Int Symp Mycotoxins 1983: 23-31.
Mutonyi MD. Invasion of groundnuts by storage fungi. M.Sc. Thesis, Kampala, Makerere University, 1975.
King AD, Hocking AD, Pitt JI. Dichloran-rose bengal medium for enumeration and isolation of molds from foods. Appl Environ Microbiol 1979; 37: 959-964.
Pitt JI, Hocking AD. Fungi and Food Spoilage. Sydney. Academic Press, 1985.
Hocking AD, Pitt JI. Dichloran glycerol medium for enumeration of xerophilic fungi from low moisture foods. Appl. Environ Microbiol 1980; 39: 488-492.
Pitt JI, Hocking AD, Samson RA, King AD. Recommended methods for mycological examination of foods, 1992. In: Samson RA, Hocking AD, Pitt JI, King AD, eds. Modern Methods in Food Mycology, Amsterdam: Elsevier, 1992: 365-368.
Kurtzman CP, Rogers R, Hesseltine CW. Microbiological spoilage of mayonnaise and salad dressings. Appl Microbiol 1971; 21: 870-874.
Raper KB, Fennell DI. The genus Aspergillus. Baltimore, Maryland: Williams and Wilkins, 1965: 686 pp.
Booth C. The genus Fusarium. Kew, Surrey, UK, Commonwealth Mycological Institute, 1971. 237 pp.
Ellis MB. Dematiaceous hyphomycetes. Kew, Surrey, UK, Commonwealth Mycological Institute, 1971. 608 pp.
Domsch KH, Gams W, Anderson T-H. Compendium of Soil Fungi. London, Academic Press, 1980. 859 pp.
Pitt JI. The genus Penicillium and its teleomorphic states Eupenicillium and Talaromyces. London: Academic Press, 1979. 634 pp.
Pitt JI, Hocking AD. Fungi and food Spoilage. 2nd edition, London, UK: Blackie Academic and Professional, Chapman &; Hall, 1997. 593 pp.
Ong PS, Gaucher GM. Protease production by thermophilic fungi. Can J Microbiol 1973; 19: 129-133.
Ho HH, Foster B. Starch utilisation by Phytophthora species. Mycopathologia et Mycologia Applicata 1972; 46: 335-339.
Bridge PD. An evaluation of some physiological and biochemical methods as an aid to the characterization of species of Penicillium Subsection Fasciculata. Journal of General Microbiology 1985; 131: 1887-1895.
Joffe AZ. The mycoflora of fresh and stored groundnut kernels in Israel. Mycopathologia et Mycologia Applicata 1969; 39: 255-264.
Moubasher AH, El-Kady IA, Farghaly SM. The mycoflora of some Egyptian seeds and their potentialities for production of aflatoxins. 2nd. International I.U.P.A.C. sponsored symposium on mycotoxins in foodstuffs, Pulawy (Poland), July 23-25, 1974.
Moubasher AH, EI-Hissy FT, Abdel-Hafez SI, Hassan SKM. The mycoflora of peanuts in Egypt. Mycopathologia 1979; 68(1): 39-46.
El-Maghraby OMO, El-Maraghy SSM. Mycoflora and Mycotoxins of peanut (Arachis hypogaea L.) seeds in Egypt. 1. Sugar fungi and natural occurrence of mycotoxins. Mycopathologia 1987; 98: 165-170.
El-Maghraby OMO, EI-Maraghy SSM. Mycoflora and Mycotoxins of peanut (Arachis hypogaea L.) seeds in Egypt III. Cellulose-decomposing and mycotoxin-producing fungi. Mycopathologia 1988; 104: 19-24.
Hanlin RT. Invasion of peanut fruits by Aspergillus flavus and other fungi. Mycopathologia et Mycologia Applicata 1970; 40: 341-348.
McDonald D. Fungal infection of groundnut fruit before harvest. Trans Br mycol Soc 1970; 54(3): 453-460.
Munimbazi C, Bullerman LB. Molds and mycotoxins in foods from Burundi. Journal of Food Protection 1996; 59(8): 869-875.
Taber RA, Schroeder HW. Aflatoxin-producing potential of isolates of the Aspergillus flavus-oryzae group from peanuts (Arachis hypogaea). Applied Microbiology 1967; 15(1): 140-144.
Hanlin RT. The distribution of peanut fungi in the Southeastern United States. Mycopathologia et Mycologia Applicata 1973; 49(4): 227-241.
Pitt JI, Hocking AD, Bhudhasamai K, Miscamble BF, Wheeler KA, Tanboon-EK P. The normal mycoflora of commodities from Thailand. I. Nuts and Oilseeds. Int J Food Microbiol 1993; 20: 211-226.
Martinsmaciel ER, Machinski M, Pereira SRC, Takahachi G, Kemmelmeier C, Nishiyama P. Incidence of aflatoxins and Aspergillus flavus in peanuts consumed in Maringa City, Brazil: Arquivos de Biologia e Tecnologia 1996; 39(4): 807-813.
Lisker N, Michaeli R, Frank ZR. Mycotoxigenic potential of Aspergillus flavus strains isolated from groundnuts growing in Israel. Mycopathologia 1993; 122: 177-183.
Diener UL, Cole RJ, Sanders TH, Payne GA, Lee LS, Klich MA. Epidemiology of aflatoxin formation by Aspergillus flavus. Ann Rev Phytopathol 1987; 25: 249-270.
Horn BW, Dorner JW. Soil populations of Aspergillus species from Section Flavi along a transect through peanut-growing regions of the United States. Mycologia 1998; 90(5): 767-776.
Pitt JI, Dyer SK, McCammon S. Systemic invasion of developing peanut plants by Aspergillus flavus. Letters in Applied Microbiology 1991; 13: 16-20.
Hasan HAH. Studies on toxigenic fungi in roasted foodstuff (salted seed) and halotolerant activity of emodin-producing Aspergillus wentii. Folia Microbiol 1998; 43(4): 383-391.
Zohri AA, Saber SM. Filamentous fungi and mycotoxin detected in coconut. Zentralbl Mikrobiol 1993; 148: 325-332.
Okpokwasili GC, Molokwu CN. Yeast and mould contaminations of vegetable oils. Bioresource Technology 1996; 57(3): 245-249
Abdel-Hafez All, Saber SM. Mycoflora and mycotoxin. of hazelnut (Corylus avellana L.) and walnut (Juglans regia L.) seeds in Egypt. Zentralbl Mikrobiol 1993; 148:137-147.
Doster MA, Michailides TJ. Aspergillus molds and aflatoxins in pistachio nuts in California. Phytopathology 1994; 84: 583-590.
Heperkan D, Aran N, Ayfer M. Mycoflora and aflatoxin contamination in shelled pistachio nuts. J. Sci. Food Agric. 1994; 66: 273-278.
Wells JM, Payne JA. Toxigenic species of Penicillium, Fusarium, and Aspergillus from weevil-damaged pecans. Can J Microbiol 1976; 22: 281-285.
Kinderlerer JL. Fungi in desiccated coconut. Food Microbiol 1984; 1: 205-207.
Mojtahedi H, Rabie CJ, Lubben A, Steyn M, Danesh D. Toxic aspergilli from pistachio nuts. Mycopathologia 1979; 67: 123-127.
Jimenez M, Mateo R, Querol A, Huerta T, Hernandez E. Mycotoxins and mycotoxigenic moulds in nuts and sunflower seeds for human consumption. Mycophathologia 1991; 115: 122-128.
Bilgrami Z, and Ghaffar A. Location of fungi in almond (Prunus amygdalus) seed. Pakistan Journal of Botany 1997; 29(1): 167-170.
Kinderlerer JL. Spoilage in desiccated coconut resulting from growth of xerophilic fungi. Food Microbiol 1984; 1: 23-28.
Kinderlerer JL, Kellard B. Ketonic rancidity in coconut due to xerophilic fungi. Phytochemistry 1984; 23: 2847-2849.
Abdel-Sater MA, Ismail MA. Ecological and enzymatic studies on fungi associated with biscuits in Egypt. International Biodeterioration and Biodegradation 1993; 31: 277-292.
Petruccioli M, Federici F, Miller MW. Extracellular enzyme production in species of the genus Penicillium.. Mycologia 1988; 80(5): 726-728.
Moharram AM, Abdel-Gawad KM, EI-Maraghy SSM. Ecological and physiological studies on fungi associated with human hair. Folia Microbiol 1988; 33: 363-371.
El-Kady IA, Mazen MB, Saber SM. Some enzymatic activities of fungi isolated from cotton seeds and cotton seed products. Qatar Univ Sci Bull 1984; 4: 85-93.
Ismail MA. Degradative enzymes and fungal flora associated with the Egyptian foodstuff Kishk. International Biodeterioration and Biodegradation 1993; 31: 143-157.
Abdel-Gawad KM. Mycological and some physiological studies of keratinophilic and other moulds associated with sheep wool. Microbiological Research 1997; 152(2): 181-188.
Garcilepe R, Nuero OM, Reyes F, Santamaria F. Lipases in autolysed cultures of filamentous fungi. Letters in Applied Microbiology 1997; 25(2): 127-130.
Hou CT. Characterization of new Yeast lipases. Journal of the American Oil Chemists Society 1997; 74(11): 1391-1394.
Miura T, Yamane T. Screening for fungi that have high lipolytic and acidolytic activities in biomass support particles. Bioscience Biotechnology and Biochemistry 1997; 61(8): 1252-1257.
Long K, Ghazali HM, Ariff A, Man YC, Bucke C. Substrate preference of mycelium-bound lipase from a strain of Aspergillus flavus Link. Biotechnology Letters 1998; 20(4): 369-372.
Christensen CM, Olafson JH, Geddes WF. Grain storage studies 8, Relation of molds in moist stored cotton seed to increased production of carbon dioxide, fatty acids, and heat. Cereal Chem. 1949; 26: 109-128.
Christensen CM, Kaufmann HH. Deterioration of stored grains by fungi. Annual Review of Phytopathology 1965; 3: 69-84.
Hesseltine CW. Microbial losses in field crops in international shipment. In: Kurata Hiroshi, Hesseltine CW, eds. 1982, Proceedings of the fourth International Symposium on Toxic Microorganisms, Tokyo, Japan, October 6-8, 1981, 187-202.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Ismail, M.A. Deterioration and spoilage of peanuts and desiccated coconuts from two sub-Saharan tropical East African countries due to the associated mycobiota and their degradative enzymes. Mycopathologia 150, 67–84 (2001). https://doi.org/10.1023/A:1010863507652
Issue Date:
DOI: https://doi.org/10.1023/A:1010863507652