Impact of Wheat Flour Infestation by some Insects on its Quantity and Quality Loss, Fungal Contamination and Mycotoxins

• Published in: International journal of agriculture and biology 2016-12, Vol.18 (6), p.1122-1130
• Main Authors: Gabarty, A., El Nour, Salwa Abou
• Format: Article
• Language: English
• Subjects: Aspergillus; Cladosporium; Corcyra cephalonica; Ephestia kuehniella; Eurotium; Penicillium; Tribolium confusum; Triticum aestivum
• ISSN: 1560-8530; 1814-9596
• DOI: 10.17957/IJAB/15.0233

Wheat flour samples were artificially infested with Corcyra cephalonica, Ephestia kuehniella, Tribolium confusum (separately) and with the three insect populations together. The effect of insects' infestation on wheat flour quantity and quality loss, fungal contamination and presence of mycotoxins was studied after two months of storage (25 plus or minus 2 degree C and 65%RH). Wheat flour infested with insects was sieved into two portions (sieved and residual flour) after insects populations have been recorded. The results revealed radical changes in weight loss, population density of insects, nutritional composition, interaction between insects and fungal contamination in the flour samples. The maximum residual flour loss was recorded by C. ceplalonica followed by E. kuehniella while the minimum residual loss was induced by T. confusum. The flour consumption by the tested insects may be arranged in descending order as follows: three insects tested together > C. cephalonica > T. confusum > E. kuehniella. There was a significant correlation between the amount of flour consumed and insect population. Also, there was a significant increase in the total protein contents and decrease in the monosaccharaides and disaccharides in all infested sieved and residual flour samples tested. The average log total molds count in control flour samples was 1.28, while the average log of insect infested flour samples ranged from 2.36 to 4.34. Seven to ten fungal species belonging to five genera (Aspergillus, Penicillium, Cladosporium, Eurotium and Emercilla) were isolated from control and infested flour samples. Many fungal species were isolated from infested flour, but most of them belong to Aspergillus and Penicillium. Aflatoxins B1, B2 were detected in all flour samples, but at different levels. Ochratoxin A was not detected in the control samples and C. cephalonica flour samples while it was detected in flour samples infested with the other treatment.