Microbial contamination and mycotoxins from nuts in Riyadh, Saudi Arabia

Suaad S. Alwakee, Laila A. Nasser

Research output: Contribution to journalArticleResearchpeer-review

11 Citations (Scopus)

Abstract

The occurrence of harmful aflatoxins from agricultural products varies with geographic location, farming practices and processing. To date, no data was reported from Saudi Arabia on mycotoxin content of nuts and edible seeds. Forty samples of edible nuts and dried seeds were randomly collected from different locations in Al-Riyadh, Saudi Arabia. Fungi were detected by seed-plate and dilutions plate method and were cultured on glucose-Czapek's agar, sucrose-Czapek's agar and starch yeast agar. Purified fungal isolates were identified morphologically. Mycotoxins were extractedusing chloroform and detected by thin layer chromatography. Bacterial analysis was done using total plate count method. There was a predominance of A. niger and A. flavus in all medium types. Aflatoxin B1 (8.5 μg mL-1) was detected in peanuts containing A flavus. Aflatoxin B1 (1.7 μg mL-1) and B2 (1.7 μg mL-1) was detected in sunflower seeds containing A terreus. T2 toxin (2.8 mg mL-1) was detected in pumpkinseeds containing Stachybotrys chartarum and DAS (2.4 μg mL-1) was detected in a salted peanut sample containing Trichthecium roseum. Four nut samples showed contamination with bacteria. Turkish pine seeds and American walnut had total plate counts of 12×10. Pakistani pine seeds and Iranian salted pistachio had TPC of 3×10. Listeria monocytogenes was isolated from American walnut samples. Government authorities for food safety consumption should continue to monitor and set appropriate guidelines and information initiatives for public knowledge on the safety of these agricultural products whole year round.

Original languageEnglish
Pages (from-to)613-630
Number of pages18
JournalAmerican Journal of Food Technology
Volume6
Issue number8
DOIs
Publication statusPublished - 18 Apr 2011

Fingerprint

Nuts
Saudi Arabia
Mycotoxins
microbial contamination
nuts
mycotoxins
Seeds
seeds
Juglans
agar
Agar
aflatoxin B1
walnuts
agricultural products
Aflatoxin B1
amsonic acid
plate count
peanuts
Stachybotrys chartarum
Pinus

Keywords

  • Aflatoxin
  • Aspergillus species
  • Glucose-czapek's agar
  • Mycotoxin
  • Osmophilic
  • Osmotolerant fungi

Cite this

Alwakee, Suaad S. ; Nasser, Laila A. / Microbial contamination and mycotoxins from nuts in Riyadh, Saudi Arabia. In: American Journal of Food Technology. 2011 ; Vol. 6, No. 8. pp. 613-630.
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Alwakee, SS & Nasser, LA 2011, 'Microbial contamination and mycotoxins from nuts in Riyadh, Saudi Arabia', American Journal of Food Technology, vol. 6, no. 8, pp. 613-630. https://doi.org/10.3923/ajft.2011.613.630

Microbial contamination and mycotoxins from nuts in Riyadh, Saudi Arabia. / Alwakee, Suaad S.; Nasser, Laila A.

In: American Journal of Food Technology, Vol. 6, No. 8, 18.04.2011, p. 613-630.

Research output: Contribution to journalArticleResearchpeer-review

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