Riba A, Mokrane S, Mathieu F, Lebrihi A, Sabaou N
Laboratoire de Recherche sur les Produits Bioactifs et la Valorisation de la Biomasse, Ecole Normale Supérieure de Kouba, BP 92 16050 Vieux Kouba, Alger, Algeria.
Int J Food Microbiol. 2008 Feb 29;122(1-2):85-92. doi: 10.1016/j.ijfoodmicro.2007.11.057. Epub 2007 Nov 29.
Wheat is a basic staple food for very large segments of the population of Algeria. The aim of this study is to analyse ochratoxin A (OTA)-producing mould and OTA-contaminated wheat. To evaluate the mycoflora and the potential for OTA production by Aspergillus strains, a total of 85 samples of wheat destined for human consumption were collected from two regions in Algeria (Tizi Ouzou and Setif) during the following phases: preharvest, storage in silos, and after processing. The mean value counts of fungi ranged from 275 to 1277 CFU g(-1). The dominant genus was Aspergillus, predominantly A. flavus, A. niger and A. versicolor. The other isolated species were A. ochraceus, A. alliaceus, A. carbonarius, A. terreus, A. fumigatus, A. candidus and Aspergillus spp. The occurrence and the levels of the genus Penicillium, Fusarium, Alternaria and Mucor were substantially lower than those of Aspergillus. The storage in silos shows high levels of Aspergillus (66 to 84%), especially A. flavus, but A. niger and other fungi were isolated at relatively low percentages. Equal distribution of the fungal contamination into the bran, flour and semolina fractions was observed from Flour Mill and Semolina Mill. The genus Aspergillus remained present at high levels at several phases of the production process. In addition, the ability to produce OTA by 135 isolates belonging to eleven species of Aspergillus and 23 isolates of Penicillium spp. was analyzed using fluorescent detection-based HPLC. Thus, it was found that 51 isolates (32.3%) were ochratoxigenic. All isolated strains of A. ochraceus (12) and A. alliaceus (6) produced OTA at concentrations ranging from 0.23 to 11.50 microg g(-1). Most of the A. carbonarius strains (80%) were OTA producers (0.01 to 9.35 microg g(-1)), whereas A. terreus (50%), A. niger (28%), A. fumigatus (40%), A. versicolor (18%) and Penicillium spp. (21.7%) were low level producers (0.01 to 0.07 microg g(-1)). The concentration of OTA was determined in 30 samples of wheat. OTA was detected in 12 (40%) of the samples at levels ranging from 0.21 to 41.55 microg kg(-1).
小麦是阿尔及利亚很大一部分人口的基本主食。本研究的目的是分析产赭曲霉毒素A（OTA）的霉菌和受OTA污染的小麦。为了评估曲霉菌株的真菌区系和产生OTA的潜力，在收获前、筒仓储存和加工后等阶段，从阿尔及利亚的两个地区（提济乌祖和塞蒂夫）共采集了85份供人类食用的小麦样本。真菌的平均计数范围为275至1277 CFU g(-1)。优势属为曲霉属，主要是黄曲霉、黑曲霉和杂色曲霉。其他分离出的种有赭曲霉、蒜曲霉、碳黑曲霉、土曲霉、烟曲霉、白曲霉和曲霉属其他种。青霉属、镰刀菌属、链格孢属和毛霉属的出现率和含量显著低于曲霉属。筒仓储存显示曲霉属含量很高（66%至84%），尤其是黄曲霉，但黑曲霉和其他真菌的分离率相对较低。从面粉厂和粗粒面粉厂观察到真菌污染在麸皮、面粉和粗粒面粉部分分布均匀。曲霉属在生产过程的几个阶段都保持高含量。此外，使用基于荧光检测的高效液相色谱法分析了属于曲霉属11个种的135个分离株和23个青霉属分离株产生OTA的能力。结果发现，51个分离株（32.3%）产OTA。所有分离出的赭曲霉菌株（12株）和蒜曲霉菌株（6株）产生的OTA浓度范围为0.23至11.50 μg g(-1)。大多数碳黑曲霉菌株（80%）是OTA生产者（0.01至9.35 μg g(-1)），而土曲霉（50%）、黑曲霉（28%）、烟曲霉（40%）、杂色曲霉（18%）和青霉属（21.7%）是低水平生产者（0.01至0.07 μg g(-1)）。在30份小麦样本中测定了OTA的浓度。在12份（40%）样本中检测到OTA，含量范围为0.21至41.55 μg kg(-1)。
