Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Mycoflora and Co-Occurrence of Fumonisins and Aflatoxins in Freshly Harvested Corn in Different Regions of Brazil  [PDF]
Liliana O. Rocha,Viviane K. Nakai,Raquel Braghini,Tatiana A. Reis,Estela Kobashigawa,Benedito Corrêa
International Journal of Molecular Sciences , 2009, DOI: 10.3390/ijms10115090
Abstract: Natural mycoflora and co-occurrence of fumonisins (FB1, FB2) and aflatoxins (AFB1, AFB2, AFG1 and AFG2) in freshly harvested corn grain samples from four regions of Brazil were investigated. Fusarium verticillioides was predominant in all samples. Analysis of fumonisins showed that 98% of the samples were contaminated with FB1 and 74.5% with FB1 + FB2, with toxin levels ranging from 0.015 to 9.67 μg/g for FB1 and from 0.015 to 3.16 μg/g for FB2. Twenty-one (10.5%) samples were contaminated with AFB1, seven (3.5%) with AFB2 and only one (0.5%) with AFG1 and AFG2. Co-contamination with aflatoxins and fumonisins was observed in 7% of the samples. The highest contamination of fumonisins and aflatoxins was observed in Nova Odessa (SP) and Várzea Grande (MT), respectively. The lowest contamination of these mycotoxins was found in Várzea Grande and Nova Odessa, respectively.
Effect of Planting Density, Irrigation Regimes, and Maize Hybrids with Varying Ear Size on Yield, and Aflatoxin and Fumonisin Contamination Levels  [PDF]
Hamed K. Abbas, Henry J. Mascagni Jr., H. Arnold Bruns, W. Thomas Shier
American Journal of Plant Sciences (AJPS) , 2012, DOI: 10.4236/ajps.2012.310162
Abstract: Corn (maize, Zea mays L.) hybrids expressing the flexibility trait in ear size (number of kernels per ear) are marketed for ability to give higher yields under adverse conditions. Altered kernel number is associated with altered number of silk, a major route for infection of kernels by aflatoxin-producing fungi such as Aspergillus flavus. The effect of plant density and irrigation level on yield and accumulation of aflatoxins and fumonisins in harvested grain was compared in a fixed-ear hybrid (Pioneer 33K81), a semi-flexible ear hybrid (Pioneer 3223) and a flexible ear hybrid (Golden Acres 8460) over a range of seeding densities (49,400, 61,750, 74,700, 86,450, and 98,800 seeds·ha–1) in non-irrigated, moderately-irrigated (6.4 cm soil water deficit) and well-irrigated plots (3.8 cm soil water deficit), during three years with variable rainfall. Irrigation increased yields in all hybrids, but in the absence of irrigation, yields were highest with the semi-flexible ear trait hybrid. In general, the hybrid with the flexible ear trait had lower optimal seeding densities than the other hybrids for each soil water regime. In general, kernel number was least affected by seeding density in the hybrid with fixed-ear trait compared to the semi- and flexible ear hybrids. The lowest levels of aflatoxin and of fumonisin contamination in harvested grain were associated with the flexible ear trait at all rainfall and irrigation levels, but there was no evidence that reducing stress by lowering seeding density reduced mycotoxin contamination. Inoculation with A. flavus resulted in much higher levels of aflatoxin and significantly higher levels of fumonisin contamination in grain of all hybrids under most conditions of rainfall and irrigation, suggesting that factors that promote A. flavus infection can affect production of both mycotoxins.
Mycoflora of Maize Harvested from Iran and Imported Maize  [PDF]
Ali Reza Khosravi,Mahdi Mansouri,Ali Reza Bahonar,Hojjatollah Shokri
Pakistan Journal of Biological Sciences , 2007,
Abstract: The natural occurrence of fungal contamination was evaluated in stored maize in three different agro-ecological zones (Iran, Brazil and China). A total of 45 samples were analyzed and 685 fungal isolates were identified. The most frequent isolated fungi from maize originated from Iran, Brazil and China were Fusarium sp. (17.3, 17.9 and 37.1%), Aspergillus sp. (9.3, 17.4 and 19.7%), Penicillium sp. (5.8, 15.2 and 17.6%), Rhizopus sp. (2.4, 3.2 and 3.5%), Mucor sp. (1.1, 1.6 and 1.3%), Cladosporium sp. (1.6, 1.9 and 1.9%), Alternaria sp. (1.1, 1.6 and 1.3%), Geotrichum sp. (0, 0 and 0.3%), Acromonium sp. (0.5, 0.8 and 0%) and Absidia sp. (0, 0.8 and 0.5%), respectively. Significant difference was observed between the frequency of fungal isolates of Iranian maize and foreign products (p<0.0005). Maize mycoflora profiles showed that Fusarium verticillioides and Aspergillus flavus prevailed in 30.7 and 13.3% of the samples from China, in 12 and 5.3% of the samples from Iran and 11.7 and 11.5% of the samples from Brazil, respectively. There were significant differences in the frequency of Fusarium verticillioides in Chinese maize with other countries products (p<0.0005) and that of Aspergillus flavus in Iranian maize with other countries (p<0.002). The results emphasize that farmers and consumers should be alerted to the danger of fungal contamination in maize.
Performance and egg quality of laying hens fed diets containing aflatoxin, fumonisin and adsorbent
Siloto, EV;Sartori, DRS;Oliveira, EFA;Sartori, JR;Fascina, VB;Berto, DA;
Revista Brasileira de Ciência Avícola , 2011, DOI: 10.1590/S1516-635X2011000100004
Abstract: the effects of aflatoxin and fumonisin and their combination on egg production and quality, as well as the efficacy of a mycotoxin adsorbent in reducing or eliminating these effects in commercial layers. a number of 168 layers with initial age of 37 weeks were submitted to an experimental period of 56 days. a completely randomized experimental design in a 3x2+1 factorial arrangement was applied (3 treatments with mycotoxins: aflatoxin (af), fumonisin (fu), or aflatoxin + fumonisin (af+fu); 2 treatments with or without adsorbent; and a control group that was fed no mycotoxins, nor adsorbent), totaling 7 treatments with 6 replicated of 4 birds/cage. the dietary inclusion levels were 1ppm af, 25ppm fu, and 2 kg adsorbent/ton feed. birds fed af presented the lowest percentage of lay (p=0.0594). egg mass was the lowest (p<0.05) in the af+fu treatment (49.49g). the treatment with af resulted in higher eggshell thickness and strength (p<0.05) than the fu treatment and the control group. the inclusion of the adsorbent in the af contaminated feed reduced eggshell strength, which returned to levels similar to those of the control group. the observed changes indicate that aflatoxin is toxic at a concentration of 1ppm, and that the effects of fumonisin were less evident as a function of the low dose applied. the inclusion of the glucan (2kg/ton) effectively reverted some of the toxic effects of aflatoxin and, at lower extension, those of fumonisin, when these mycotoxins were invidually added to commercial layer feeds.
Effects of Aflatoxin B1 and Fumonisin B1 on the Viability and Induction of Apoptosis in Rat Primary Hepatocytes  [PDF]
Deise H. B. Ribeiro,Fabiane L. Ferreira,Valéria N. Da Silva,Simone Aquino,Benedito Corrêa
International Journal of Molecular Sciences , 2010, DOI: 10.3390/ijms11041944
Abstract: The present study evaluated the effect of aflatoxin B 1 (AFB 1) and fumonisin B 1 (FB 1) either alone, or in association, on rat primary hepatocyte cultures. Cell viability was assessed by flow cytometry after propidium iodine intercalation. DNA fragmentation and apoptosis were assessed by agarose gel electrophoresis and acridine orange and ethidium bromide staining. At the concentrations of AFB 1 and FB 1 used, the toxins did not decrease cell viability, but did induce apoptosis in a concentration and time-dependent manner.
Fumonisins in corn: correlation with Fusarium sp. count, damaged kernels, protein and lipid content
Ono, Elisabete Yurie Sataque;Biazon, Luciana;Silva, Marcelo da;Vizoni, édio;Sugiura, Yoshitsugu;Ueno, Yoshio;Hirooka, Elisa Yoko;
Brazilian Archives of Biology and Technology , 2006, DOI: 10.1590/S1516-89132006000100008
Abstract: natural fungal and fumonisin contamination were evaluated in 109 freshly harvested corn samples from paraná state and correlated to damaged kernels (%). in addition, healthy and damaged kernels of 24 corn samples were selected in order to compare the mycoflora profile and fumonisin levels. the correlation among protein/lipid content and fumonisin levels was also analyzed in the 15 most frequently cultivated corn hybrids. total fungal colony count in 109 freshly harvested corn samples ranged from 1.9x104 to 3.5x106 cfu/g, fusarium sp. count from 1.0x103 to 2.2x106 cfu/g, and fumonisin levels from 0.13 to 20.38 μg/g. total fungal colony/fusarium sp. count and fumonisin levels showed positive correlation (p < 0.05). in addition, there was a positive correlation between damaged kernels (%) and total fungal colony/fusarium sp. count (p < 0.05). fumonisin levels in healthy kernels ranged from 0.57 to 20.38 μg/g, while in the damaged kernels it ranged from 68.96 to 336.38 μg/g. no significant correlation among the fumonisin levels and the protein or lipid content was observed. the results showed the importance of constant monitoring of toxigenic fungi and fumonisin contamination in corn and corn-based foods in order to assure the quality and safety of products and to minimize the potential hazards to human and animal health.
Factors Affecting Aflatoxin Contamination of Harvested Maize in the Three Agroecological Zones of Uganda  [PDF]
A.N. Kaaya,W. Kyamuhangire,S. Kyamanywa
Journal of Applied Sciences , 2006,
Abstract: A survey was conducted in 2003 to establish aflatoxin levels in maize and the associated farmer practices in the three agroecological zones of Uganda. Maize kernels obtained from farmers in the Mid-Altitude (moist) zone had the highest aflatoxin contaminated samples (83%) and mean aflatoxin levels of 9.7 ppb followed by those from the Mid-Altitude (dry) where 70% were contaminated with a mean of 7.7 ppb, while the kernels sampled from the Highland zone had the least contaminated samples (55%) and mean aflatoxin levels of 3.9 ppb. Aflatoxin contamination in maize grain was positively related to leaving maize to dry in the field for more than three weeks, drying maize without husks, drying maize on bare ground, shelling maize by beating, heaping maize on the floor during storage and use of baskets for storage of maize. The practices that negatively impacted on aflatoxin development in maize in the agroecological zones were sorting before storage, storage of maize in shelled form, storage of maize in bags, use of improved granary as storage structures, storage of maize above fireplace and use of synthetic pesticides. Thus, those practices that reduce aflatoxin contamination of maize should be adopted by all farmers in Uganda to reduce the health hazards associated with consumption of contaminated maize grain.
Effects of Aflatoxin B1 and Fumonisin B1 on Blood Biochemical Parameters in Broilers  [PDF]
Eliana N. C. Tessari,Estela Kobashigawa,Ana Lúcia S. P. Cardoso,David R. Ledoux,George E. Rottinghaus,Carlos A. F. Oliveira
Toxins , 2010, DOI: 10.3390/toxins2040453
Abstract: The individual and combined effects of dietary aflatoxin B1 (AFB1) and fumonisin B1 (FB1) on liver pathology, serum levels of aspartate amino-transferase (AST) and plasma total protein (TP) of broilers were evaluated from 8 to 41 days of age. Dietary treatments included a 3 × 3 factorial arrangement with three levels of AFB1 (0, 50 and 200 μg AFB1/kg), and three levels of FB1 (0, 50 and 200 mg FB1/kg). At 33 days post feeding, with the exception of birds fed 50 mg FB1 only, concentrations of AST were higher (p < 0.05) in all other treatment groups when compared with controls. Plasma TP was lower (p < 0.05) at six days post feeding in groups fed 200 mgAFB1/kg alone or in combination with FB1. At day 33 days post feeding, with the exception of birds fed the highest combination of AFB1 and FB1 which had higher plasma TP than control birds, plasma TP of birds fed other dietary treatments were similar to controls. Broilers receiving the highest levels of AFB1 and FB1 had bile duct proliferation and trabecular disorder in liver samples. AFB1 singly or in combination with FB at the levels studied, caused liver damage and an increase in serum levels of AST.
Susceptibility of the In-shell Brazil Nut Mycoflora and Aflatoxin Contamination to Ozone Gas Treatment during Storage  [cached]
Barbara Nantua Evangelista Giordano,Janaina Nones,Vildes Maria Scussel
Journal of Agricultural Science , 2012, DOI: 10.5539/jas.v4n8p1
Abstract: The effect on fungi load, toxigenic Aspergillus strains and aflatoxin (AFL) contamination of stored in-shell Brazil nut (Bertholletia excelsa H.B.K.) ozone (O3) gas treated were evaluated. Groups of nuts obtained from retail market were submitted to O3 atmosphere at different concentrations (10, 14, 31.5 mg/l) and stored for 180 days. The O3 treatment affected Brazil nuts mycoflora growth, reduced their moisture content (mc) and degraded AFLs. From the three O3 concentrations applied, 31 mg/l (5 hours exposition) was able to successfully destroy fungi contamination (initial: 4.83 logcfu/g to ng-no grow), including the Aspergillus flavus and A. parasiticus species, since Day One after application. On the other hand, they were still able to grow, at the lower O3 concentrations (10; 14 mg/l), however only in the first days of storage and at reduced number though (from 4.83 to 3.5/3.3 logcfu/g, respectively). Despite of the O3 concentrations applied, AFLs were not detected in all nut samples O3 treated since Day One of application up to the method LOQ of 1.34 μg/kg except for 10 mg/kg). As expected, a reduction of mc (9.43 to 7.32 %) and aw (0.82 to 0.63) due to gas stream application was registered throughout the storage period, which increased with the O3 time of exposure resulting cruncher Brazil nuts. Apart from low cost and simple technology to be applied during storage in-land or in containers before shipping, O3 treatment it is a promising alternative for contamination control and is environment friendly.
Effect of an esterified glucomannan on laying hens exposed to combined mycotoxins (aflatoxin B1, zearalenone and fumonisin B1)  [cached]
L. Rizzi,M. Simioli,A. Altafini,A. Zaghini
Italian Journal of Animal Science , 2011, DOI: 10.4081/ijas.2003.s1.465
Abstract: Mycotoxin toxicity depends on species, exposure time, age, sex, health and possible synergistic effects of other mycotoxins present in feed. In poultry, aflatoxin B1 (AFB1) and fumonisin B1 (FB1) are associated with poor growth performance, lowered feed utilization efficiency, liver damage and immunosuppression; metabolites may persist in tissues and eggs. Exposure of mature hens to zearalenone (ZEN) apparently does not cause adverse effects, but ZEN residues and α and β zearalenol persist in liver and muscle (Kuiper-Goodman et al., 1987) and may be transmitted to egg yolk (Dailey et al., 1990). Various treatments and dietary strategies have been tried to reduce mycotoxin levels in contaminated commodities...
Page 1 /100
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.