Cyclopiazonic acid degradation by aqueous ozone

Ozone is a chemical agent with great potential to reduce mycotoxins, it was effective against to reduce some mycotoxins. In view of this it was aimed of this work study the Cyclopiazonic acid (CPA) degradation by aqueous ozone. The degradation of exogenously CPA introduced in mobile phase was confirmed by High performance liquid Chromatography (HPLC). In parallel it was tested the effect of sodium formate (SF), to evaluate the influence of this chemical to neutralize ozone after adding CPA to ozone reaction, since it is a chemical used to stop ozone reaction. Results shown that SF did not influence aqueous ozone to degrade the CPA, since the quickness of ozone reaction

Aflatoxins and cyclopiazonic acid producer strains supressed by aqueous ozone

Ozone is a potential antioxidant substance with effect against microorganism. Four ozone concentrations (0, 1, 10 and 20 mg/L) were applied for 10 minutes to Aspergillus flavus and A. parasiticus spores suspensions (103 cfu/mL). Aqueous ozone was effective against both isolates at the lowest ozone concentration tested. Under the tested conditions, spores inactivation was from 91 to 100%. All ozone treatments performed effective fungi control. The two isolates used in these assays were screened for mycotoxin production by HPLC. The A. flavus strain produced cyclopiazonic acid and Aflatoxin B1 and the A. parasiticus strain produced Aflatoxins B1, B2, G1 and G2. The ozone effect on these mycotoxins was not evaluated

Potential of aqueous ozone to control aflatoxigenic fungi in Brazil nuts

The Brazil nut (Bertholethia excelsa) is an important non timber forest product (NTFP) from the Amazonian forest. Despite their nutritious value, Brazil nuts are susceptible to contamination with Aspergillus section Flavi fungi and consequently with aflatoxins. Since aqueous ozone reduces microorganisms population and has oxidant effect on aflatoxins, the effect of ozone on. Both natural and artificially contaminated Brasil nuts were studied in the present work. The former were inoculated with either 1x106 or 1x107 conidia mL-1 of A. flavus (MUM 9201). Previous assays were carried out to determine optimal parameters of the treatment. Different aqueous ozone contact time was assayed. The duration was controlled by the addition of a sodium formate solution. Such assays evidenced that the effect of ozone is almost immediate. Also, different ozone concentrations were assayed. The optimum ozone concentration depended on the initial viable spores on the nutshell. Also, the effect of the ozonization on the shell nut color was assessed by measuring chromaticity values of the treated fruits in the L*a*b* space coordinates. High concentrations of ozone affected both the luminosity and the hue of the nutshell. Finally, a concentrated aqueous ozone solution was assayed on both natural and artificially contaminated nuts. The remaining viable spores in the ozone solution were recorded and the rate of inactivation for each treatment was determined by assessing the ratio between the CFU of each treatment and the control. Ozonized nuts were also plated on MEA to recover the fungi population. Aqueous ozone was effective in reducing the conidia of Aspergillus flavus and the natural fungal population associated to Brazil nuts, although it seems to affect external appearance of the shell. The aqueous ozone solution may be recommended to control other mycotoxin producer Aspergilli, since ozone is regarded a generally recognized as safe (GRAS) product and it has been already used in many agricultural products, including the organically labels one like Brazil nuts.Fundação para a Ciência e a Tecnologia (FCT

Screening of fungal metabolites in Brazil nuts using LC/MS/MS

The aim of this study was to evaluate quantitatively the occurrence of fungal metabolites in Brazil nuts. Nuts were collected from Agroforest production areas in Amazon basin region. A total of 235 mycotoxins were investigated/screened by a multi-mycotoxin method based on HPLC-MS/MS. The recovery was between 56 and 136%. Fifteen mycotoxins were detected and quantified, in at least one sample; namely, aflatoxins B1, B2, G1, and M1, kojic acid, sterigmatocystin, methyl-sterigmatocystin, citrinin, cyclosporin A, cyclosporin C, cyclosporin D, cyclosporin H, rugulosin, altenariol-methylether and emodin. Aflatoxins were detected in just 1 sample (20%), but above its legal limit in Brazil and EU. Ochratoxin A and Fusarium toxins were not detected. Alternariol-methylether (from 0.75 to 3.2 g.kg-1) was detected in all five samples. This is the first study dealing with the detection of kojic acid, citrinin, cyclosporin A, cyclosporin C, cyclosporin D, cyclosporin H, rugulosin, altenariol-methylether and emodin in Brazil nuts

Mycobiota predominant and aflatoxins content in shell and shelled Brazil nuts

Brazil nuts (Bertholletia excelsa Humb. and Bonpl.) are an important product of the Brazilian Amazon. Currently, its marketing is compromised by the high incidence of aflatoxins (AF). The most known naturally occurring AF are named AFB1, AFB2, AFG1, and AFG2. This study aimed to identify the potentially aflatoxigenic mycobiota associated with shelled Brazil nuts and with the shells, and to determine which one of these fractions contributes to aflatoxins (AF) contamination, since that official method use integral Brazil nuts samples to AF test. Samples of Brazil nuts were collected from the agro forestry system production area in Amazonian rain forest, in Brazil. These samples were split in shells and shelled nuts, and the total count of Aspergillus spp. was analysed after sanitation (sodium hypochlorite 1% / 10 minutes) and without sanitation, by plating AFPA medium, for 7 days, at 25 °C. The isolates identified as Aspergillus section Flavi were plated in YES medium (5days at 25°C) for determination of the aflatoxigenic potential by agar plug technique. To analyze AF, 500 g samples were milled and were extracted with chloroform. The chromatographic analysis was performed by HPLC–FD system in an isocratic mode [Waters pump W600, Waters module autosampler W717, Fluoresce detector W2475 and column Waters X-Terra (4.6x150mm and 5μm -- RP18)]. The mobile phase was water milli-Q/acetonitrile/methanol (600:150:150 v/v) and the injected volume was 5μL both to standards and samples. The average incidence of infection from Aspergillus spp. in sections Flavi, Nigri and Circumdati were 48%, 8% and 1%, respectively. The sanitization treatment reduced the fungi counts. There were AF production by fungi isolated from both types of samples, 30% of the samples were positive for AFB1, AFB2, AFG1 and AFG2 and 23.8% produced AFB1, AFB2, and AFG1. Concerning the Brazil nuts AF analysis, it was observed that the concentration of AFB1 and AFG1 obtained were higher than AFB2 and AFG2. The AFB1 content was 35.281 and 1.782 μg/Kg in shelled Brazil nuts and shells, respectively. AFB2 and AFG2 were detected only in shelled samples. The HPLC-FD presented limits of detection (LOD) and quantification (LQ) of 0.2 and 0.4 μg/kg, respectively

Micotoxinas: contributos da Micoteca da Universidade do Minho (MUM) para a segurança alimentar.

A Micoteca da Universidade do Minho (MUM), fundada em 1996, tem como missão ser uma colecção de fungos filamentosos com o objectivo principal de manter e fornecer estirpes com qualidade e autenticidade para a investigação em biotecnologia e ciências da vida, e laboratórios de ensaio, actuando também como um centro de conhecimento, informação e formação na área da micologia. Dentro desta missão, a MUM tem estado envolvida em projectos que procuram dar resposta aos riscos alimentares derivados da contaminação fúngica

Near-infrared spectroscopy applied to the detection of multiple adulterants in roasted and ground arabica coffee

Roasted coffee has been the target of increasingly complex adulterations. Sensitive, non-destructive, rapid and multicomponent techniques for their detection are sought after. This work proposes the detection of several common adulterants (corn, barley, soybean, rice, coffee husks and robusta coffee) in roasted ground arabica coffee (from different geographic regions), combining near-infrared (NIR) spectroscopy and chemometrics (Principal Component Analysis—PCA). Adulterated samples were composed of one to six adulterants, ranging from 0.25 to 80% (w/w). The results showed that NIR spectroscopy was able to discriminate pure arabica coffee samples from adulterated ones (for all the concentrations tested), including robusta coffees or coffee husks, and independently of being single or multiple adulterations. The identification of the adulterant in the sample was only feasible for single or double adulterations and in concentrations ≥10%. NIR spectroscopy also showed potential for the geographical discrimination of arabica coffees (South and Central America).info:eu-repo/semantics/publishedVersio

Evaluate of amplificability of genomic DNA from two in-house protocols of conserved sequence by biosynthesis pathway of filamentous fungi producers of aflotoxins

In the present study, the polymerase chain reaction (PCR) was evaluated as a molecular technique to identify the aflotoxins filamentous fungi producers. The PCR was carry out using a specific pair of primers for b-tubulin amplification, that has a high conserved sequence in filamentous fungi. It was tested two DNA extraction methods: Lee et al. and Weising et. al. both methods were efficient in DNA isolation. The results showed that using Lee et. al. method was possible to extract DNA with better quality, and the PCR runs presented the expected band for b-tubulin. These results showed that the lee et al. method and PCR is adequate for Aspergillus sp. detection. There is a perspective to improve the detection using specific primers to amplify genes related to aflotoxin biosynthesis, allowing the development of a molecular method to evaluate the risk contamination of this substance in food

Fungos micotoxigênicos e ocratoxina a em cafés com permanência prolongada na planta e no solo, colhidos nas regiões do cerrado mineiro e baiano

In Brazil, the regions called ‘Cerrado’ in Minas Gerais and Bahia states are expressive coffee producers and stand out for productivity and quality of grain produced. The bloom unevenness of coffee in Brazil leads to fruit with various stages of maturity at the harvest period. As a result, some producers use low quality grains with long soil or plant contact and mix them with those of quality to compose the harvest. The objective of this work was to study coffee fruits with soil contact of up to 90 days evaluating ochratoxin A (OTA) levels, humidity dynamics and water activity in coffee fruits harvested every 30 days. The coffee with prolonged stay on the plant, showed no major variations in humidity and water activity levels during the 120 days studied. However, in coffee with prolonged stay on the soil, after 90 days, the humidity and water activity levels varied dramatically according each region. During this period, the humidity and water activity were 14.15 and 0.74%, 6.64% and 0.63 for the Cerrado Mineiro and Baiano, respectively. Despite the coffee with prolonged stay in the plant having been heavily colonized by Aspergillus ochraceus G. Wilh. (1877),  OTA contamination was not detected, but in coffees with prolonged stay on the soil, high levels of OTA were observed, 49.42 and 30.93 μg.kg -1, for the Cerrado Mineiro and Baiano, respectively. There was OTA  production even in the grains with low water activity, indicating how the complexity of the system in the field interferes with the micotoxigenic dynamic fungi growth and consequently in OTA production.No Brasil, as regiões do Cerrado Mineiro e Baiano são destaque pela produtividade e qualidade dos grãos produzidos. A florada desuniforme do café no Brasil implica em frutos com diversos estágios de amadurecimento no período da colheita. Assim, frutos não colhidos oportunamente permanecem na planta ou caem no solo, e quando aproveitados farão parte de uma safra de baixa qualidade. Portanto, foi objetivo deste trabalho estudar frutos de café com exposição prolongada na planta e no solo, avaliando a colonização por fungos micotoxigênicos, a produção de ocratoxina A (OTA) e a dinâmica de umidade e atividade de água nos frutos nessas regiões produtoras. O café com permanência prolongada na planta não apresentou grandes variações nos teores de umidade e atividade de água durante os 120 dias estudados. Entretanto, o café com permanência prolongada no solo, apresentou, após 90 dias, variação drástica nos teores de umidade e atividade de água entre as regiões estudadas. Nesse período, a umidade e atividade de água foram de 14,15% e 0,74, 6,64% e 0,63 para o Cerrado Mineiro e Baiano, respectivamente. Apesar do café com permanência prolongada na planta ter sido intensamente colonizado por Aspergillus ochraceus G. Wilh. (1877), não foi detectada a presença de OTA. No café com permanência prolongada no solo detectaram-se níveis muito elevados, 49,42 e 30,93 µg.kg-1 de OTA, no Cerrado Mineiro e Baiano, respectivamente. Pode-se constatar que independente da região de interesse, cafés com permanência prolongada na planta ou no solo interferem decisivamente na qualidade do café colhido

Identification of filamentous fungi, assessment of extraneous matter and physicochemical analysis of artisanal and industrialized açaí cream: Identificação de fungos filamentosos, avaliação de matérias estranhas e análises físico-químicas em creme de açaí artesanal e industrializado

Açaí (Euterpe oleracea and E. precatoria) tree produces berries that are industrialized especially as desserts, such as ice creams, creams, and açai pulp. The processing according to Good Manufacturing Practices (GMP) is fundamental to obtain safe foods for consumption. This work aimed to evaluate the quality of açaí cream marketed in Sete Lagoas, Minas Gerais, Brazil, concerning the presence of fungi and extraneous matter, as well as to evaluate certain physicochemical parameters. It was analysed 21 samples of açaí cream (10 artisanal and 11 industrialized). All 21 samples had acceptable physicochemical quality standards. However, regarding mycological analyses, 23.8% of the samples presented filamentous fungi and 100% presented yeast count. The genera of the predominant filamentous fungi were: Cladosporium spp. (93.9%), Penicillium spp. (1.7%), Rhizopus spp. (2.6%), Paecilomyces spp. (0.9%) and Mucor spp. (0.9%). A total of 57% of the samples presented extraneous matter and the vegetal tissues that represent a health risk were the main material found, therefore, there is a need for adjustments in terms of good processing practices