مستوى تلوث حبوب الشعير و منتجاته ( دقيق الشعير و الزميتة ) بسموم الأوكراتوكسينات A و B من مطاحن خاصة بمدينة طرابلس
Abstract The present study aims to isolate and identify such fungi natural occurrence barley grain collected from Tripoli, Libyia, fungi production of ochratoxins, survey natural occurrence of ochratoxins in barley and its products (flouer and zometa) , study the effect of kind barley on ochratoxins production and determination the chemical composition of barley and its products. The effect of barley flour and zometa processes on ochratoxin A in barley was studied. 1- Natural incidence of fungi on barley grains: Samples are plated on Czapek's agar medium. The infection and total fungal count was calculated the results indicated that the infection was ranged from 85 to 100% and total fungal count was ranged from 93 to 150 isolates. The naturally infected with fungi belonging to genera Aspergillus spp, penicillium spp and Fusarium spp. Aspergillus spp, penicillium ssp and Fusarium spp were ranged from 36.70% to 58%, 17.3% to 36.6% and 16.0 to 31.3% respectively. 2- Natural occurrence of fungi producing ochratoxins: A- Aspergillus ochraceus: Sixty – three of A. ochraceus isolates was found from 608 Aspergillus spp isolates. Twenty isolates from 63 of A ochraceus was found positive for ochratoxins production . The production of toxins were 56.49 mg/Litter, 1.72 mg /Litter and 0.62 mg / Litter YES for ochratoxins A, B and C respectively. B- Penicillium verrucostum Thirty – six P. verrucostum isolates from 360 Penicillium spp Were found. Nineteen isolates of P. verrucostum from 36 isolates were found a positive to ochratoxins production . The production of toxins was 44.5 mg /Litter , 2.4 mg / Litter and 0.38 mg / Litter for ochratoxin A, B, C respectively. 3-Natureal occurrence of ochratoxins in barley and its products : A- Barley grainsThe results indicated that 38 out from 66 barley samples (57%) was found positive to ochratoxina A, concentration was ranged from 0.7 – 12.4 µg/kg with mean value of 3.91 µg /kg barley. Ochratoxin B and C did not found in any samples. 4- Natural occurrence of ochratoxins in barely products. B- Barley flour: Concerning to the occurrence of ochratoxins in barley products, the results revealed that 29 out from 66 (43%) flour samples were positive to ochratoxin A, the rang was 1.34-3.39 µg/kg and mean of 2.4/µg /kg.C- Zometa flour: The results indicated that 36% from 66 zometa samples were positive for ochratoxin A . the concentration was ranged from 0.55 to 1.9 µg/kg with mean 1.2 µg/kg zometa flour.5- Effect of barley kind on ochratoxins productionThe results appeared that both Aspergillus ochraceus and penicillium verrucosum very were growth and produced ochratoxins on all kind of barley and its products. (barley flour zomata flour). For Aspergillus ochraceus: The results indicated that the product of toxins were ranged from 11.09 to 19.43 mg/kg and 0.21 to 2.41 mg /kg sample for ochratoxin A and ochratoxin B respectively. For Penicillium verrucostum: The results also indicated that the production of toxins ranged from 9-5 to 11.52 and 0.09 to 0.93 mg/kg sample for ochratoxin A and ochratoxin B respectively. The results improved that both Aspergillus ochraceus and P. verrucostum produced ochratoxins A and B on all barley grains and its products , when suitable condition from temperature and moisture content were found . Fate of ochratoxin A residues in barley grains during flour and zometa processes. The results showed that (cleaning , removal of broken grains, atrophic , at other as well as the process of grinding) and screening (barley flour) caused a loss of 8 and 30% of ochratoxin A concentration respectively. The initial aperations for barley and grain milling and screening process (barley flour) led to 35.6% of total ochratoxin A concentration (50 µg/kg barley). Results also indicated that the process of roasting temperature 200°C for 15 min. and milling and screening destruction 13 and 35% from ochratoxin A concentration respectively . Zometa process steps were caused 52% from initial of ochratoxin A concentration (50µg/kg barley). It could be concluded therefore that cleaning , removal of broken grains, atrophic , at other as well as the process o grinding) and barley and grain milling screening of pulses contaminated with ochratoxin A does not complete eliminate health hazard.
صفي الدين عبد الله خليفة إنبيه (2008)
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