Flávio Fonseca Veras

Estimated exposure to zearalenone, ochratoxin A and aflatoxin B1 through the consume of bakery products and pasta considering effects of food processing

The objective of this research was to estimate the processing effect on mycotoxins levels and the exposure to zearalenone (ZEA), ochratoxin (OTA) and aflatoxin B1 (AFB1) through the consumption of pasta and bakery products. The higher reduction percentage of mycotoxins was observed in cake production (95, 90 and 70% for ZEA, OTA and AFB1, respectively). Bread and biscuit showed similar reduction in mycotoxins levels (89 and 90% for ZEA; 80 and 85% for OTA; 36 and 40% for AFB1, respectively). The lower reduction in the levels of mycotoxins has been observed for pasta (75, 65 and 10% for ZEA, OTA and AFB1, respectively). The consumption of these products could represent 12.6% of the maximum tolerable daily intake of ZEA and 30.5% of the tolerable weekly intake of OTA. The margin of exposure value related to the exposure to AFB1 was 24.6. The exposure to ZEA and OTA through the consumption of bakery products and pasta would not represent risk for consumer health, (although conjugated forms were not determined). However, the exposure to AFB1 represents a risk (even without considering the AFB1-conjugated forms).

Inhibition of filamentous fungi by ketoconazole-functionalized electrospun nanofibers

Nanotechnology strategies have been used for delivery and controlled release of antimicrobial drugs. Electrospun nanofibers can be versatile vehicles to incorporate antimicrobials. In this work, poly-ε-caprolactone nanofibers functionalized with ketoconazole were produced by electrospinning and tested against filamentous fungi. Ketoconazole-free nanofibers were produced as controls. Functionalized nanofibers showed antifungal activity against Aspergillus flavus, A. carbonarius, A. niger, Aspergillus sp. A29, Fusarium oxysporum and Penicillium citrinum by agar diffusion test. Inhibitory zones ranging from 6 to 44mm were observed, this larger inhibition was against A. flavus. The nanofibers were incubated in different simulant solutions to evaluate the ketoconazole release, which was only detected in the solution containing 5% (v/v) Tween 20. Electron microscopy images showed the nanofibers with ketoconazole presented mean diameters of 526nm, and the degradation of the nanofiber structures could be observed by electron microscopy after incubation in simulant solution. Infrared and thermal analyses indicated that ketoconazole was dispersed without chemical interactions with the polycaprolactone matrix. These results suggest that polycaprolactone nanofibers incorporating ketoconazole may be an interesting alternative to control pathogenic fungi.

Inhibition of mycotoxin-producing fungi by Bacillus strains isolated from fish intestines

Bacillus strains isolated from the aquatic environment of the Brazilian Amazon region were tested for their activity against mycotoxigenic fungi. All tested bacteria showed antifungal activity, inhibiting at least 7 indicator fungi. Four Bacillus strains showing promising antifungal results were subsequently evaluated for their activity in reducing mycelial growth rate, sporulation, spore germination percentage, and mycotoxin production. Bacillus sp. P1 and Bacillus sp. P11 had a remarkable antifungal effect on toxigenic fungi. Washed bacterial cell suspension of strains P1 and P11 (107CFU/ml) reduced by >70% the fungal colony diameters, including a complete inhibition of ochratoxin A (OTA) producing Aspergillus spp. Significant reduction of growth rate, sporulation and spore germination were also observed. The bacteria influenced the production of mycotoxins, causing a reduction around 99 and 97% in AFB1 and OTA concentration, respectively. Chromatographic analysis revealed the presence of lipopeptides (iturin A and surfactin isomers) in butanol extracts of cell-free supernatants and cell pellets of strains P1 and P11. Furthermore, antifungal activity of these extracts was confirmed against A. flavus A12 and A. carbonarius ITAL293, producers of AFB1 and OTA, respectively. These bacterial strains could be promising biocontrol agents against toxigenic fungi.

Exposure risk assessment to ochratoxin A through consumption of juice and wine considering the effect of steam extraction time and vinification stages

The goals of this study were (i) to verify the effect of steam extraction used in juice production and the stages of vinification on the ochratoxin A (OTA) levels found in grapes naturally contaminated, and (ii) evaluate the risk of exposure to this toxin when the daily consumption of juice and wine is followed to prevent cardiovascular disease. OTA-producing fungi were isolated from Cabernet Sauvignon, Moscato Itálico and Concord grapes harvested from the same vineyard and intended to produce red wine, white wine and juice, respectively. The highest levels of this toxin were found in the Concord grapes used for juice production. Although greater reduction in OTA levels occurred during juice production (73%) compared to winemaking (66 and 44%, for red and white, respectively), the estimated OTA exposure through juice was higher than the tolerable intake established for this toxin by JECFA. The risk associated with juice consumption, rather than wine, can be explained by (i) higher OTA levels found in Concord must than those of Cabernet and Moscato, indicating that Concord grapes appear to be more susceptible to OTA production by toxigenic fungi; and (ii) the daily recommended juice consumption is higher than those proposed to red wine.

Antimicrobial Activities of Metal Nanoparticles

Metals have been used since ancient times to combat infectious diseases. With the introduction of nanotechnology, metal nanoparticles have gaining increased attention as antimicrobial agents due to their broad inhibitory spectrum against bacteria, fungi, and viruses. Although silver nanoparticles have been mostly investigated due to their recognized antimicrobial properties, while other metal nanoparticles have received increasing interest as antimicrobials. These include gold, zinc oxide, titanium oxide, copper oxide, and magnesium oxide nanoparticles, since their antibacterial effects have been described. Metal nanoparticles can exert their effect on microbial cells by generating membrane damage, oxidative stress, and injury to proteins and DNA. In addition, metal nanoparticles can be associated with other nanostructures and used as carriers to antimicrobial drugs, improving the array of potential applications.

Atividade Antagonista de Rizobactérias Isoladas de Plantas de Milho Ao Crescimento Micelial e Germinação de Conídios de Fusarium Verticillioides Produtor de Fumonisina B1.

Tiago Einloft, Flavio Veras, Patricia Oliveira, Rafael Dionello.Atividade Antagonista de Rizobacterias Isoladas de Plantas de Milho Ao Crescimento Micelial e Germinacao de Conidios de Fusarium Verticillioides Produtor de Fumonisina B1.. In: Anais do 12o Congresso Latinoamericano de Microbiologia e Higiene de Alimentos MICROAL 2014 [= Blucher Food Science Proceedings, num.1, vol.1]. Sao Paulo: Editora Blucher, 2014. DOI 10.5151/foodsci-microal-069 Atividade Antagonista de Rizobacterias Isoladas de Plantas de Milho Ao Crescimento Micelial e Germinacao de Conidios de Fusarium Verticillioides Produtor de Fumonisina B1.

Fate of Zearalenone, Ochratoxin A and Aflatoxin B1 Present in Wheat Flour Used for Bread Production

Juliane Elisa Welke, Flavio Fonseca Veras, Bruna Dachery, Emili Keller Bol, Debora Senger.Fate of Zearalenone, Ochratoxin A and Aflatoxin B1 Present in Wheat Flour Used for Bread Production. In: Anais do 12o Congresso Latinoamericano de Microbiologia e Higiene de Alimentos MICROAL 2014 [= Blucher Food Science Proceedings, num.1, vol.1]. Sao Paulo: Editora Blucher, 2014. DOI 10.5151/foodsci-microal-096 Fate of Zearalenone, Ochratoxin A and Aflatoxin B1 Present in Wheat Flour Used for Bread Production

Estimative of Dietary Exposure To Zearalenone, Ochratoxin A and Aflatoxin B1 Through the Consume of Pasta Bakery Products

Juliane Elisa Welke, Flavio Fonseca Veras, Bruna Dachery, Emili Keller Bol, Debora Senger.Estimative of Dietary Exposure To Zearalenone, Ochratoxin A and Aflatoxin B1 Through the Consume of Pasta Bakery Products. In: Anais do 12o Congresso Latinoamericano de Microbiologia e Higiene de Alimentos MICROAL 2014 [= Blucher Food Science Proceedings, num.1, vol.1]. Sao Paulo: Editora Blucher, 2014. DOI 10.5151/foodsci-microal-095 Estimative of Dietary Exposure To Zearalenone, Ochratoxin A and Aflatoxin B1 Through the Consume of Pasta Bakery Products

Inhibition of Growth of Aspergillus Flavus and Aflatoxin Production by Pseumononas Sp. Strain 4B

Flavio Fonseca Veras, Roberta Fontoura, Ana Paula Folmer Correa, Tiago Centeno Einloft, Adriano Brandelli, Juliane Elisa Welke.Inhibition of Growth of Aspergillus Flavus and Aflatoxin Production by Pseumononas Sp. Strain 4B. In: Anais do 12o Congresso Latinoamericano de Microbiologia e Higiene de Alimentos MICROAL 2014 [= Blucher Food Science Proceedings, num.1, vol.1]. Sao Paulo: Editora Blucher, 2014. DOI 10.5151/foodsci-microal-093 Inhibition of Growth of Aspergillus Flavus and Aflatoxin Production by Pseumononas Sp. Strain 4B

Incidence of Aspergillus in Grapes Intended To Juice and Wine Prodution

Bruna Dachery, Sheila Canossa, Emilli Keller Bol, Debora Senger, Flavio Veras, Vitor Manfroi, Juliane welke.Incidence of Aspergillus in Grapes Intended To Juice and Wine Prodution. In: Anais do 12o Congresso Latinoamericano de Microbiologia e Higiene de Alimentos MICROAL 2014 [= Blucher Food Science Proceedings, num.1, vol.1]. Sao Paulo: Editora Blucher, 2014. DOI 10.5151/foodsci-microal-058 Incidence of Aspergillus in Grapes Intended To Juice and Wine Prodution