Mycoflora of Fungal Contamination in Wheat Storage (Silos) in Golestan Province, North of Iran

Abstract

Background: Cereal products are susceptible to mould damage during pre-and post-harvesting stages of the production. The regional specificity of Golestan province in the northern region of of Iran, with its high temperature and high relative humidity, acts as a leading factor for the growth of aflatoxin-producing fungi. It is well known that contamination of starch-based ingredients with mycotoxigenic fungi is a risk factor among the consumers due to its aflatoxins. Objectives: This survey was carried out to determine the extent of fungal contamination of wheat in three silos of Golestan province in Iran. Materials and Methods: 34 samples from three active silos were collected in order to clean the polyethylene bags. Wheat analyzed for fungal contamination and aflatoxins extracted by immunoaffinity column chromatography, and measured by HPLC method. Results: The most common moulds isolated were Alternaria spp. 26.7%, Aspergillus niger 21.4%, Fusarium spp. 17.8%, Aspergillus flavus 10.7%, Cladosporium spp. 10.7%, Penicillium spp. 8.9%, and Rhizopus spp. 3.5%. The screening of aflatoxin, B1, B2, G1 and G2 was carried out. 10(29.4%) samples of wheat had traces of aflatoxin, but in a level lower than the standard levels [Institute of Standards and Industrial Research of Iran (ISIR< 15 ng/g)].Conclusions: Despite the lower detected aflatoxin levels (lower than the ISIR level), the fungal contamination rate could not be neglected. Since the isolated mycotoxigenic fungi such as Aspergillus spp. and Fusarium spp. are important in food industry, it would be possible that the increased retention time of samples might have raised the detected contamination rate.

Challenges to Safe Wheat Storage

“…In one of the literatures of the previous research, presence of fungi was tested in 34 samples collected from 3 silos. Results of this experiment proved that presence of fungi produced aflatoxins in majority of tested samples [5]. It is worth mentioning that fungi represent the main factors of starchy grain contamination (mycotoxigenic).…”

“…Despite all precautions taken in modern silos, many studies have shown that fungi are flourishing on wheat grains and in the air of these reservoirs [5]. Several research findings have confirmed the presence of harmful and toxic fungi in many silos, not only on stored grains but also on wheat flour derived from those silos.…”

Optimization of the extraction parameters of Aloe Vera polyphenols and study of antioxidant and antifungal activities: application to molds isolated from durum wheat

“…If the storage conditions are unfavorable, these molds are factors of biological deterioration of the wheat affecting the quality of the raw materials, or the sanitary quality by the secretion of mycotoxins [55]. In other studies, Joshaghani et al [56] isolated seven strains from stored For the Alternaria spp1 strain; the extract showed a moderate activity which regresses with the augmentation of the concentration, but at the concentration of 1000 ppm, the negative effect appears (the increase of the growth of the mold compared to the control). All concentrations of Aloe Vera extract solutions have strong activity against Alternaria spp2 strain.…”

Comparative Study on Antimicrobial Activity of <i>Vitex negundo</i> var. <i>negundo</i> and <i>Vitex negundo</i> var. <i>purpurascens</i>

“…Fungi such as species of Aspergillus, Penicillium, Rhizopus, Mucor etc., cause deterioration of stored commodities. Besides, these fungi also produce toxins such as aflatoxins and others which produce various symptoms on consumption (Amadi and Adeniyi, 2009;Keller et al, 2012;Joshaghani et al, 2013;Suleiman and Omafe, 2013). Fungicides have been extensively used for control of plant pathogenic fungi.…”