Skip to main content
Log in

Fungal flora and mycotoxins of six kinds of nut seeds for human consumption in Saudi Arabia

  • Mycotoxicoses And Mycotoxins
  • Published:
Mycopathologia Aims and scope Submit manuscript

Abstract

A wide range of moulds representing several genera and species, was recorded in this study from 5 seed samples of each almond, cashew nut, chestnut, hazelnut, pistachio nut and walnut collected from different markets in Ar' Ar, Saudi Arabia. The total counts of fungi were widely fluctuated between 1960–7704 and 1948–7434 colonies/g dry seeds on glucose-Czapek's and glycerol agar media at 28°C, respectively, and represented twenty genera, 53 species and 2 varieties of fungi. The prevalent fungi on the 2 agar media wereAspergillus flavus, A. niger andPenicillium chrysogenum. On glucose-Czapek's agar,Rhizopus stolonifer andAspergillus flavus var.columnaris were isolated from all 6 kinds of nut,A. parasiticus from 5 kinds andA. fumigatus from 4 kinds with high frequencies.Eurotium species were completely absent on glucose-Czapek's agar but they were isolated in high frequency from all kinds of nut on glycerol agar medium. The different nut samples were analyzed by thin layer chromatography for the presence of aflatoxins B1, B2, G1 & G2, citrinin, ochratoxins, patulin, sterigmatocystin, diacetoxyscirpenol, T-2 toxin and zearalenone. Aflatoxins B1 & G1 were detected in 3 out of the 5 samples tested of chestnut at concentrations ranging between 20 to 60 µg/kg. All other samples of almond, cashew nut, hazelnut, pistachio nut, and walnut that were analyzed were mycotoxin free.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  1. Abdel-Hafez AH, Saber SM. Mycoflora and mycotoxin of hazelnut (Corylus avellana L.) and walnut (Juglans regia L.) seeds in Egypt. Zentralbl Mikrobiol 1993; 148: 137–48.

    PubMed  Google Scholar 

  2. Burdaspal PA, Gorostidi A, Tejedor MC. A survey of the occurrence of aflatoxins in edible nuts in Spain. Abstracts, International Symposium and Workshop on Food Contamination ‘Mycotoxins and Phycotoxins’, 4–15 November 1990, Cairo, Egypt.

  3. El-Magraby OMO, El-Maraghy SSM. Mycoflora and mycotoxins of peanut (Arachis hypogaea L.) seeds in Egypt, I: Sugar fungi and natural occurrence of mycotoxins. Mycopathologia 1987; 98: 165–70.

    PubMed  Google Scholar 

  4. El-Magraby OMO, El-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.

    PubMed  Google Scholar 

  5. FAO. Food and nutrition paper, No. 13, Perspective on mycotoxin. Rome: Food and Agricultural Organization of the United Nations, 1979.

    Google Scholar 

  6. Jimenez M, Mateo R, Querol A, Huerta T, Hernandez E. Mycotoxins and mycotoxigenic moulds in nuts and sunflower seeds for human consumption. Mycopathologia 1991; 115: 122–28.

    Google Scholar 

  7. Stoloff L. Occurrence of mycotoxins in foods and feeds. In J.V. Rodricks (ed.) Mycotoxins and other fungal related food problems [Advances in Chemistry Series, No. 149]. Washington, DC: American Chemical Society, 1976.

    Google Scholar 

  8. Christensen CM. Influence of small difference in moisture content upon the invasion of hard red winter wheat byAspergillus restrictus andA. repens. Cereal Chem 1963; 40: 385–90.

    Google Scholar 

  9. Moubasher AH, El-Naghy MA, Abdel-Hafez SH. Fungal flora of three grains in Egypt. Mycopath et Mycol Appl 1972; 47: 261–74.

    Google Scholar 

  10. Al-Doory Y. Laboratory medical mycology. London: Lea and Febiger, 1980, 410 pp.

    Google Scholar 

  11. Domsch KH, Gams W, Anderson TH. Compendium of soil fungi. New York: Academic Press, 1980, 859 pp.

    Google Scholar 

  12. Ellis MB. More dematiaceous hyphomycetes. Kew (UK): IMI, 1976, 507 pp.

    Google Scholar 

  13. Kozakiewicz Z.Aspergillus species on stored products. CAB International Mycological Institute. Mycological Papers 1989; 161:1–188.

    Google Scholar 

  14. Onions AHS, Allsopp D, Eggins HOW, Smith's introduction to industrial mycology. London: Edward Arnold, 1981, 398 pp.

    Google Scholar 

  15. Pitt JI. The genusPenicillium and its teleomorphic statesEupenicillium andTalaromyces. London: Academic Press, 1979, 634 pp.

    Google Scholar 

  16. Pitt JI. A laboratory guide to commonPenicillium species. Kew (UK): IMI, 1985, 184 pp.

    Google Scholar 

  17. Raper KB, Fennell DI. The genusAspergillus. Baltimore (USA): Williams and Wilkins, 1965, 686 pp.

    Google Scholar 

  18. Samson RA., Van Reenen-Hoekstra ES. Introduction to food-borne fungi. Baarn, The Netherlands, Centraalbureau voor Schimmelcultures, 1988.

  19. Sivanesan A. Graminicolous species ofBipolaris, Curvularia, Drechslera, Exserohilum and their teleomorphs. CAB International Mycological Institute. Mycological Papers 1987; 158: 1–261.

    Google Scholar 

  20. AOAC. Association of Official Analytical Chemists. Official methods of analysis, 13th ed., Washington, DC 1980, 429 pp.

  21. Gimeno A. Thin layer chromatographic determination of aflatoxins, ochratoxins, sterigmatocystin, zearalenone citrinin, T-2 toxin, diacetoxyscirpenol, penicillic acid patulin and penitrem A. J AOAC 1979; 62: 579–85.

    Google Scholar 

  22. Roberts BA, Patterson DSP. Detection of twelve mycotoxins in mixed animal feedstuffs, using a novel membrane cleanup procedure. J AOAC 1975; 58: 1178–81.

    Google Scholar 

  23. Scott PM, Lawrence JW, Van Walbeak W. Detection of mycotoxins by thin-layer chromatography. Application to screening of fungal extracts. Appl Microbiol 1970; 20:839–42.

    PubMed  Google Scholar 

  24. Jones BD. Method of aflatoxin analysis G. 70. London: Tropical Products Institute, 1972, 58 pp.

    Google Scholar 

  25. Przybylski W. Formation of derivatives of aflatoxins on TLC plates. J AOAC 1975; 58:163–64.

    Google Scholar 

  26. Hanlin RT. Fungi in developing peanut fruits. Mycopath et Mycol Appl 1969; 38: 99–101.

    Google Scholar 

  27. Moubasher AH, El-Hissy FT, Abdel-Hafez SH, Hassan SKM. The mycoflora of peanuts in Egypt. Mycopathologia 1979; 68: 39–46.

    Google Scholar 

  28. Jackson CR. A field study of fungal associations on peanut fruit. Ca Agr Exp Sta Bull 1968; 26: 29.

    Google Scholar 

  29. Norton DC, Menon SK, Flangas AL. Fungi associated with unblemished spanish peanuts in Texas. Pl Dis Rep 1956; 40: 374–76.

    Google Scholar 

  30. Hocking AD, Pitt JI. Dichloran-Glycerol medium for enumeration of xerophilic fungi from low-moisture foods. Appl Environ Microbiol 1980; 39; 488–92.

    PubMed  Google Scholar 

  31. Abdel-Hafez SH, Moubasher AH, Barakat A. Keratinophilic fungi and other moulds associated with air dust particles from Egypt. Folia Microbiol 1990; 35: 311–25.

    Google Scholar 

  32. Bullermall LB. Mycotoxins and Food Safety. Food Technology 1986; 40: 59–66.

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

Abdel-Gawad, K.M., Zohri, A.A. Fungal flora and mycotoxins of six kinds of nut seeds for human consumption in Saudi Arabia. Mycopathologia 124, 55–64 (1993). https://doi.org/10.1007/BF01103057

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF01103057

Key words

Navigation