Characterization and Inhibitory Effects of Essential Oil and Nanoemulsion from Ocotea indecora (Shott) Mez in Aspergillus Species.

The Aspergillus genus, the etiological agent of aspergillosis, is an important food contaminant and mycotoxin producer. Plant extracts and essential oils are a source of bioactive substances with antimicrobial potential that can be used instead of synthetic food preservatives. Species from the Lauraceae family and the Ocotea genus have been used as traditional medicinal herbs. Their essential oils can be nanoemulsified to enhance their stability and bioavailability and increase their use. Therefore, this study sought to prepare and characterize both nanoemulsion and essential oil from the Ocotea indecora's leaves, a native and endemic species from the Mata Atlântica forest in Brazil, and evaluate the activity against Aspergillus flavus RC 2054, Aspergillus parasiticus NRRL 2999, and Aspergillus westerdjikiae NRRL 3174. The products were added to Sabouraud Dextrose Agar at concentrations of 256, 512, 1024, 2048, and 4096 µg/mL. The strains were inoculated and incubated for up to 96 h with two daily measurements. The results did not show fungicidal activity under these conditions. A fungistatic effect, however, was observed. The nanoemulsion decreased the fungistatic concentration of the essential oil more than ten times, mainly in A. westerdjikiae. There were no significant changes in aflatoxin production.

Inhibitory Effect of GRAS Essential Oils and Plant Extracts on the Growth of Aspergillus westerdijkiae and Aspergillus carbonarius Strains.

The effect of essential oils (obtained using hydrodistillation) and plant extracts (ethanolic, aqueous, and hexanic extractions) of 10 different plants cultivated in Brazil were tested using the diffusion agar method, with the objective of evaluating the inhibitory effect of the oils and extracts on the mycelial growth of Aspergillus westerdijkiae NRRL 3174 and A. carbonarius RC 2054 (UNRC). Of the 40 essential oils and plant extracts analyzed, oregano essential oil and plant extract, rosemary essential oil, and the clove ethanolic extract were the best choice to obtain the growth parameters (radial growth rates (mm day-1) and lag phase (h)) due the good results presented and the volume of oil/extract obtained. Comparing all the essential oils and plant extracts that were tested for growth parameters, the best results were obtained for the clove ethanolic extract for both strains assayed. These results demonstrated an outstanding potential use of some of these products in prevention of fungal contamination in food. However, further studies need to be conducted to determine the ability of these oils and extracts to inhibit or reduce ochratoxin A production.

Elaboração de salsicha de peixe pargo Pagrus pagrus de tamanho reduzido proveniente da pesca de arrasto com baixo valor comercial / Development of fish sausage using low commercial value red porgy Pagrus pagrus

O objetivo deste trabalho foi desenvolver salsicha utilizando o pargo Pagrus pagrus de baixo valor comercial capturado na modalidade de pesca de arrasto e classificado como na categoria "mistura" por ter tamanho reduzido para o mercado varejista e realizar análises físico-químicas, microbiológicas, toxicológicas e sensoriais. A salsicha foi elaborada na planta piloto da Embrapa Agroindústria de Alimentos utilizando 50% de surimi e 50% de filé. As análises físico-químicas, microbiológicas e toxicológicas foram realizadas com métodos oficiais. O teste de aceitação foi realizado com 87 provadores que avaliaram o produto utilizando escala hedônica de sete pontos e também arguidos quanto à intenção de compra do produto. O produto foi considerado aceito quando 70% dos provadores atribuíram nota ≥ 4. Os resultados da composição centesimal foram: umidade 71,22%, proteínas 15,34%, lipídios totais 5,55%, carboidratos 6,11%, cinzas 1,78% e o valor energético 135,75 kcal. As avaliações microbiológicas e toxicológicas mostraram que os produtos apresentaram qualidade satisfatória conforme a legislação. A salsicha foi aceita por 82,7% dos provadores e o aspecto global do produto atingiu média de 4,93 (±1,69). Em relação à intenção de compra foi atribuída a maior porcentagem para talvez sim/talvez não (32%), seguido de provavelmente compraria (24%), e 28,1% informaram que provavelmente ou decididamente não comprariam. Com base nos resultados obtidos, conclui-se que o peixe de baixo valor agregado da categoria "mistura" resultou em produto embutido viável para o uso na tecnologia do pescado.

The aim of this work was to develop sausage using the low commercial value red porgy (Pagrus pagrus) caught in the "fish mix" category in the trawl fishery and to perform physicochemical, microbiological, toxicological and sensorial analysis. The sausage was prepared using 50% of surimi and 50% of fillet in Embrapa Food Agroindustry Pilot Plant. The physicochemical, microbiological, toxicological analyses were performed with official methods. The sensorial analyses were performed with 87 testers who evaluated the product using a hedonic scale of seven (7) points and were also accused of buying the product. The product was considered accepted when 70% of the tasters assigned a score ≥ 4. One sausage formulation was tested using 50% surimi. The results of the centesimal composition were: moisture 71.22%, proteins 15.34%, total lipids 5.55%, carbohydrates 6.11%, ash 1.78% and energy value 135.75 kcal. The parameters of microbiological and toxicological are within the current legislation for breaded products. The sausage was accepted obtaining 82.7% and the overall impression of the product reached a mean of 4.93 (± 1.69). Regarding intention to purchase for sausage, the highest percentage was attributed to maybe / perhaps not (32%), followed by likely to buy (24%), and 28.1% reported that they probably or decidedly would not buy. Based on the results obtained, it was concluded that the low commercial value fish of the "fish mix" category resulted in a viable product available for use in fish technology.

In Vitro Activity of Neem (Azadirachta indica) Oil on Growth and Ochratoxin A Production by Aspergillus carbonarius Isolates.

Aspergillus carbonarius is a saprobic filamentous fungus, food spoiling fungus and a producer of ochratoxin A (OTA) mycotoxin. In this study, the in vitro antifungal activity of neem oil (0.12% p/p of azadirachtin) was evaluated against the growth of six strains of A. carbonarius and the production of OTA. Four different concentrations of neem oil were tested in addition to three incubation times. Only the concentration of 0.3% of neem oil inhibited more than 95% of the strain's growth (97.6% ± 0.5%), while the use of 0.5% and 1.0% of neem oil showed lower antifungal activity, 40.2% ± 3.1 and 64.7% ± 1.1, respectively. There was a complete inhibition of OTA production with 0.1% and 0.3% neem oil in the four strains isolated in the laboratory from grapes. The present study shows that neem essential oil can be further evaluated as an auxiliary method for the reduction of mycelial growth and OTA production.

Qualidade microbiológica do sururu (Mytella charruana) comercializado por catadoras da Baía de Sepetiba, Rio de Janeiro, Brasil / Microbiological quality of sururu (Mytella charruana) marketed by scavengers of the Sepetiba Bay, Rio de Janeiro, Brazil

A preocupação com a qualidade do pescado é de grande importância para todos, pois é um alimento de alto valor nutritivo, mas tem grande susceptibilidade à deterioração e formação de substâncias prejudiciais à saúde, quando as condições de conservação e manipulação não são mantidas. O cultivo de moluscos bivalves além de ser uma fonte alternativa de alimentos, é uma opção para a subsistência das populações ribeirinhas de todo o litoral, à medida que a matriz alimentícia ganha espaço no mercado, principalmente nas regiões nordeste, sul e sudeste. Os sururus são organismos filtradores, capazes de absorver micropartículas em suspensão, as quais podem carrear elevadas concentrações de microrganismos patogênicos, outro fator importante relacionado a este molusco é a má condição de manipulação no beneficiamento, que pode provocar toxinfecções alimentares, ambos provocando danos à saúde. As análises microbiológicas foram realizadas em sururu in natura e após cozimento. Nas amostras analisadas houve ausência de Salmonella spp., com redução na contagem de Staphylococcus coagulase-positiva e de Coliformes Termotolerantes a 45ºC nos produtos cozidos. Os resultados são indicativos de que mesmo havendo redução de contaminação bacteriana, a manipulação das catadoras, após cozimento, é inadequada e que medidas corretivas devem ser adotadas para se obter o produto adequado bacteriologicamente ao consumo.

Fish quality has a great importance concerning to its high nutritional value, due to its great susceptibility to deterioration and occurrence of harmful substances to human health when the storage and handling conditions are not kept properly. The bivalves farming is an alternative source of food and also a source of livelihood for riverside communities, as the product is accepted in the market, mainly in the Northeast, South and Southeast regions. As filter feeders organisms, “sururu” mussels can absorb microparticles which can carry high level of pathogenic micro-organisms. Another important factor is the bad handling conditions both can lead to foodstuff infections. Microbiological analyzes were performed in raw “sururu” mussel and after cooking. The samples analyzed there was no Salmonella sp., a reduction in coagulase-positive Staphylococcus count and thermotolerant coliforms at 45 °C in baked products. Results of the analyzes showed that even with the contamination reduction, the handling of the women staff after cooking is inadequate and corrective measures should be taken to obtain a safe product for the final consumer.