Ames Test to Detect Mutagenicity of 2-Alkylcyclobutanones: A Review.

Food irradiation is an effective and safe method for preservation and long-term storage, and it is approved for use in over 60 countries for various applications in a wide variety of food products. This process is performed by use of accelerated electron beams, X-rays, or gamma radiation (60 Co or 137 Cs). 2-Alkylcyclobutanones (2-ACBs) are the only known radiolytic products generated from foods that have fatty acids (triglycerides) and are subjected to irradiation. Since the 1990s toxicological safety studies of 2-ACBs have been conducted extensively through synthetic compounds, then and tests to determine if the compounds have any mutagenic activity are strictly necessary. The Ames test was chosen by many researchers to assess the mutagenicity of 2-ACBs. The test uses distinct bacterial cell lines Salmonella typhimurium to detect point mutations at sites guanine-cytosine (G-C) and Escherichia coli to detect point mutations at sites adenine-thymine (A-T). This bibliographic research aims to bring together all the results obtained and a comparison and cell lines used, type of plates, and solvents. This research showed that no mutagenic activity was observed in any of the cell lines and concentrations evaluated by the works of authors, so the 2-ACBs compounds showed no mutagenic substance in concentrations detectable by the Ames test.

Influence of high-dose gamma radiation and particle size on antioxidant properties of Maize ( Zea mays L. ) flour

ABSTRACT Influence of high-dose gamma radiation and particle size on antioxidant properties of maize (Zea mays L.) flour was studied using response surface methodology. A central composite design based on three levels of each of particle size, in terms of mesh number (40, 60 and 80 meshes), and gamma radiation dose (25, 50 and 75 kGy) was constructed. A statistically significant dose-dependent decrease (p<0.05) in antioxidant properties of gamma irradiated flour was observed. However, an increase in the mesh number (decrease in particle size of flour) resulted in an increase in antioxidant properties. The optimum level of radiation dose to achieve maximum value of responses was found to be 50 kGy for Trolox equivalent total antioxidant activity (TETAOA), 25 kGy for iron chelating ability (ICA), 25 kGy for reducing power (RP) and 75 kGy for linoleic acid reduction capacity (LARC). However, the optimum level of mesh number to achieve desired levels of TETAOA, ICA, RP and LARC was found to be 80 meshes

Irradiation stability of folic Acid in powder and aqueous solution.

This study attempts to examine the folic acid stability after irradiation treatment, under different physical states, pH values, and atmosphere conditions. Aqueous folic acid samples, folic acid in powder, and wheat flour fortified with folic acid were irradiated by an electron beam (E-beam) between 0 (control) and 10.0 kGy. It was realized that the physical state of folic acid plays an important role on its stability toward E-beam processing, being largely unstable in solution, no matter the pH and atmosphere conditions assayed. Otherwise, folic acid in powder showed huge irradiation stability, even when mixed in a dry food matrix, such as fortified wheat flour samples.

Water quality concerns and acceptance of irradiated food: a pilot study on Mexican consumers.

BACKGROUND: Poor quality irrigation water is a major cause of disease transmission for urban inhabitants consuming fresh produce in many developing countries. Irradiation of food is an alternative approach to reducing health risks for consumers, but its implementation depends heavily on consumer acceptance. RESULTS: In this pilot study, we show that most respondents consider the water quality of Mexico City to be poor and a health risk, and would be willing to pay for irradiated food as a means of pasteurizing fresh iceberg lettuce. CONCLUSION: Irradiated food could, potentially, be accepted in developing countries that have problems with water quality. Such acceptance would presumably be due to the perception that such a novel technology would (1) alleviate water impairment, and (2) lead to economic improvement. It is then possible that the public considers that water quality is a more pressing concern than any potential side effects of food irradiation.

Radioresistance of Salmonella species and Listeria monocytogenes on minimally processed arugula (Eruca sativa Mill.): effect of irradiation on flavonoid content and acceptability of irradiated produce.

This work studied the radiation resistance of Listeria monocytogenes and Salmonella species and the effect of irradiation on leaf flavonoid content and sensory acceptability of minimally processed arugula. Immersion in ozone-treated water reduced the analyzed microorganisms by 1 log. L. monocytogenes and Salmonella were not isolated from samples. Samples of this vegetable were inoculated with a cocktail of Salmonella spp. and L. monocytogenes and exposed to gamma irradiation. D10 values for Salmonella ranged from 0.16 to 0.19 kGy and for L. monocytogenes from 0.37 to 0.48 kGy. Kaempferol glycoside levels were 4 and ca. 3 times higher in samples exposed to 1 and 2 kGy, respectively, than in control samples. An increase in quercetin glycoside was also observed mainly in samples exposed to 1 kGy. In sensory evaluation, arugula had good acceptability, even after exposure to 2 and 4 kGy. These results indicate that irradiation has potential as a practical processing step to improve the safety of arugula.

Efeito da radiação gama sobre a qualidade higiênico-sanitária de refeição pronta para o consumo / Effect of gamma radiation on the microbiological quality of meals ready to eat

O presente estudo teve como objetivo avaliar o efeito da aplicação do processo de irradiação gama em refeições prontas para o consumo, acondicionada à vácuo em bandejas de polipropileno e armazenada sob refrigeração, bem como avaliar o tempo de vida útil. As refeições foram elaboradas, acondicionadas e tratadas com radiação ionizante gama, fonte de césio, na dose de 5,00 kGy, sendo armazenadas a10oC com 80-85 por cento de umidade relativa. Foram submetidas ao controle de qualidade através de análises microbiológicas, no tempo zero, e a cada sete ou oito dias até completar os 90 dias de armazenamento, dependendo do tipo de microrganismo pesquisado, indicadores de qualidade higiênico-sanitária e/ou patógenos.(...) Os resultados do processo de irradiação em baixas doses mostra-se promissor tanto na redução e eliminação de microrganismos, como na manutenção da boa qualidade das refeições.

Efeito da radiação gama sobre a qualidade higiênico-sanitária de refeição pronta para o consumo / Effect of gamma radiation on the microbiological quality of meals ready to eat

O presente estudo teve como objetivo avaliar o efeito da aplicação do processo de irradiação gama em refeições prontas para o consumo, acondicionada à vácuo em bandejas de polipropileno e armazenada sob refrigeração, bem como avaliar o tempo de vida útil. As refeições foram elaboradas, acondicionadas e tratadas com radiação ionizante gama, fonte de césio, na dose de 5,00 kGy, sendo armazenadas a10oC com 80-85 por cento de umidade relativa. Foram submetidas ao controle de qualidade através de análises microbiológicas, no tempo zero, e a cada sete ou oito dias até completar os 90 dias de armazenamento, dependendo do tipo de microrganismo pesquisado, indicadores de qualidade higiênico-sanitária e/ou patógenos. De acordo com os resultados microbiológicos, evidenciou-se que os produtos tratados com 5,0 kGy apresentaram redução de quatro ciclos logarítrnicos na contagem total de bactérias mesófilas em placas (CTP) e de Staphylococcus coagulase positiva, eliminando totalmente este último, e redução de três ciclos logarítimos de coliformes a 450C/ g, eliminando-o, comparados com os controles. Não foram detectados coliformes a 450C/ g e E. coli, B. cereus, Clostridium sulfito redutor., Salmonella spp. e Staphylococcus coagulase positiva até o final do experimento, nas refeições irradiadas. Os resultados do processo de irradiação em baixas doses mostra-se promissor tanto na redução e eliminação de microrganismos, como na manutenção da boa qualidade das refeições.(AU)

Microbiology Evaluation of Meal Treated with Gamma Irradiation. This study aims was to evaluate the effect ofgamma irradiation on the read-to eat meals. The meals in this experiment were? ionizing radiation treatment was carried out with a 137Cs source, of 5,0 kGy doses and stored under 10?C and 80- 85% RM. Were submitted to microbiological analysis at time zero and every seven days. It was made clear by the microbiological analysis results that the products treated with 5,0 kGy presented a decrease of four logaritmic cicles in aerobic mesophilic microflora just after irradiation. Total coliforms and E. coli were not detected until the 90th day. The B. cereus, Clostridium sulphite reductor Salmonella spp. and Staphylococcus coagulase positive were also not detected in the product. The results show that the low dose irradiation process is very promising to maintain the quality of the product. (AU)

Efeito da radiação gama na sanitização da maçã Royal Gala minimamente processada / Effect of the radiation gamma in the sanitization of the Royal Gala apple minimally processed

O objetivo do presente trabalho foi verificar os efeitos da radiação gama na conservação pós-colheita da maçã Royal Gala minimamente processada, determinando a melhor dose para estender a sua vida útil, reduzindo a incidência de patógenos, durante seu armazenamento. Os frutos foram lavados em água, cortados manualmente em cubos de 2x2 cm, imersos em solução 35 de ácido ascórbico e acondicionados em bandejas de isopor envolvidas em filme plástico. A seguir foram irradiados na EMBRARAD nas doses T1 (testemunha), T2 (0,1kGy), T3 (0,2kGy), T4 (0,3kGy), T5(0,4kGy) e T6(0,5kGy), e armazenados a 5ºC com 85 por cento de umidade relativa. Aos 2, 4, 6, 8 e 10 dias de armazenamento foi avaliada a incidência de microrganismos mesófilos e psicotróficos, contagens microbiológicas dos grupos coliformes totais e fecais. Pelos resultados obtidos, pôde-se verificar, após 10 dias de armazenamento, que a irradiação mostrou ser um tratamento pós-colheita eficiente para a maçã minimamente processada, sendo que os frutos com a dose 0,5kGy, apresentaram menores quantidades de mesófilos,psicotróficos, bolores e leveduras, enquanto os frutos da testemunha apresentaram grande quantidade de mesófilos e psicotróficos. Logo, pode-se concluir que a irradiação na dose 0,5kGy foi efetiva no tratamento da maçã minimamente processada.

Efeito da radiação gama na sanitização da maçã Royal Gala minimamente processada / Effect of the radiation gamma in the sanitization of the Royal Gala apple minimally processed

O objetivo do presente trabalho foi verificar os efeitos da radiação gama na conservação pós-colheita da maçã Royal Gala minimamente processada, determinando a melhor dose para estender a sua vida útil, reduzindo a incidência de patógenos, durante seu armazenamento. Os frutos foram lavados em água, cortados manualmente em cubos de 2x2 cm, imersos em solução 35 de ácido ascórbico e acondicionados em bandejas de isopor envolvidas em filme plástico. A seguir foram irradiados na EMBRARAD nas doses T1 (testemunha), T2 (0,1kGy), T3 (0,2kGy), T4 (0,3kGy), T5(0,4kGy) e T6(0,5kGy), e armazenados a 5ºC com 85 por cento de umidade relativa. Aos 2, 4, 6, 8 e 10 dias de armazenamento foi avaliada a incidência de microrganismos mesófilos e psicotróficos, contagens microbiológicas dos grupos coliformes totais e fecais. Pelos resultados obtidos, pôde-se verificar, após 10 dias de armazenamento, que a irradiação mostrou ser um tratamento pós-colheita eficiente para a maçã minimamente processada, sendo que os frutos com a dose 0,5kGy, apresentaram menores quantidades de mesófilos,psicotróficos, bolores e leveduras, enquanto os frutos da testemunha apresentaram grande quantidade de mesófilos e psicotróficos. Logo, pode-se concluir que a irradiação na dose 0,5kGy foi efetiva no tratamento da maçã minimamente processada.(AU)

The objective of the present experiment was to verify the effects of the radiation gamma in the conservation postharvest of apple 'Royal Gala' minimally processed, determining the best dose to extend its shelf life, reducing the microorganism incidence, during its storage. The fruits were washed in water, cut manually in cubes of 2x2cm, immersed in solution of 3% of ascorbic acid and conditioned in isopor trays involved in plastic film. Afterthat, they were irradiated in the EMBRARAD company, with the doses: T1 (control), T2 (O,l kGy), T3 (O,2 kGy), T4 (0,3kGy), T5(0,4kGy) and T6 (O,5kGy), and stored under 5°e and 85% RM. To the 2, 4, 6, 8 and 10 days of storage it was evaluated the incidence of microorganisms mesophiles, psychrophils, mould, yeasts and coliforms. For the obtained results, it could be verified, after 10 days of storage, that the irradiation showed to be a treatment efficient postharvest for the apple minimally processed, and the fruits with the dose ofO,5kGy, presented smaller amounts of mesophiles, psychrophils, mould and yeasts, while the fruits contral presented great amount of mesophiles, psychrophils, mould and yeasts. Therefore, it can be concluded that the irradiation in the dose O,5kGy was effective in the treatment of the apple minimally processed. (AU)

Determination of the mineral fraction and rheological properties of microwave modified starch from Canna edulis.

The goal of this study was to evaluate the effect of the physical modification by microwave irradiation on the mineral fraction and rheological properties of starch isolated from Canna edulis rhizomes. Phosphorus, sodium, potassium, magnesium, iron, calcium and zinc were evaluated using atomic absorption spectrophotometry. Rheological properties were determined using both the Brabender amylograph and Brookfield viscosimeter. Except for the calcium concentration, mineral contents decreased significantly (p < 0.05) after microwave treatment. The amylographic profile was also modified, showing increased pasting temperature range and breakdown index, whereas the viscosity peak, viscosity at holding (95 degrees C) and cooling periods (50 degrees C), setback and consistency decreased as compared to the native starch counterpart. Although viscosity decreased in the microwaved sample, presumably due to starch changes at molecular level, it retained the general pseudo plastic behavior of native starch. It is concluded that canna starch may be modified by microwave irradiation in order to change its functional properties. This information should be considered when using microwave irradiation for food processing. Furthermore, the altered functional attributes of canna modified starch could be advantageous in new product development.

Efeito da radiação gama na sanitização da manga minimamente processada / Effect of the radiation gamma in the sanitation of the minimally processed mango

O objetivo do presente trabalho foi avaliar o efeito sanitizante da radiação gama na manga minimamente processada. Os frutos foram lavados em água, descascados, cortados manualmente em cubos de 3 x 3 cm e acondicionados em embalagens de polietileno terefltalato (tipo PET) Neoform, copos de plástico transparante (250ml) e saco plástico (0,6 micras) a vácuo. A seguir foram irradiados na EMBRARAD nas doses T1 (testemunha), T2 (0,1 kGy), T3 (0,2 kGy), T4 (0,3 kGy), T5 (0,4 kGy) e T6 (0,5 kGy), e armazenados a 5º C com 85 por cento de umidade relativa. A cada dois dias foi avaliada a incidência de coliformes, microrganismos mesófilos, psicrotróficos, bolores e leveduras. Pelos resultados obtidos, pôde-se verificar, após 10 dias de armazenamento, que os frutos com as doses de 0,4 e 0,5 kGy, armazenados em embalagem PET e copo plástico, apresentaram menores quantidades de mesófilos, psicrotróficos, bolores e leveduras, enquanto os frutos da testemunha apresentaram grande quantidades de mesófilos e psicrotróficos, bolores e leveduras, sendo considerados impróprios para o consumo no quinto dia de conservação. Logo, pode-se concluir que a radiação gama nas doses de 0,4 e 0,5 kGy foi efetiva no tratamento a manga minimamente processada.(AU)

The objective of this work was to evaluate of the effect sanitation of the irradiation on the mango minimally processed. The fruits were washed in water, peeled, manually cut in cubes of 3 x 3 and conditioned in packages of polyethylene terphalate (PET) tray Neoform, transparent plastic glass with cover (250ml), and plastic bag (0,6 micras) under vacuum. After that, they were irradiated in the EMBRARAD company, with doses T1 (control), T2 (0,1 kGy), T3 (0,2 kGy), T4 (0,3 kGy), T5 (0,4 kGy) and T6 (0,5 kGy), and stored 50C and 85% RM. Every 2 days of storage, the fruits were evaluated for the incidence of coliforms, mesophiles, psychrophils, mould and yeasts microorganisms. From ihe obtained results it is verified at the end of a lO-day period, the fruits with 0,4 and 0,5 kGy doses and packages of polyethylene terphthalate (PET) tray Neoform, transparent plastic glass with cover (25Oml),presented the smallest mesophile, psychrophile, mould and yeasts while the fruits control presented the largest mesophile, psychrophil, mould and yeasts rates, being considered for consumption from the fifth day of storage. Therefore it can be concluded with 0,4 andO,5 kgy doses was an effective treatment in the minimally processed mango. (AU)

Effect of gamma irradiation on the microbiological quality of minimally processed vegetables

Efecto de la radiación gamma en la calidad microbiológica de vegetales minimamente procesados. Se determinó la microflora inicial de apio y repollo minimamente procesado, envasado en atmósfera controlada, proveniente de un proveedor y disponible en una cadena de supermercados de la ciudad de Santiago de Chile. Aunque no se detectó E. coli ni presencia de Salmonella spp, los recuentos de aerobios mesófilos y de enterobacterias fueron elevados (= 105 ufc/g), sobrepasando en la mayoría de los casos las especificaciones de la legislación chilena. Se determinó el valor D10 para dos cepas de E. coli (ATCC 8739 y una cepa silvestre aislada de vegetales) inoculadas como microorganismos indicadores. Se estudió la variación de la población microbiana y la calidad sensorial, después de irradiar con dosis de 5 D10 (1 kGy), durante un período de almacenamiento de 7 días a 5ºC. En apio irradiado se observó una reducción de 4,7 y 3,8 ciclos logarítmicos en el recuento de aerobios mesófilos y de enterobacterias, respectivamente. En repollo la reducción fue de 3,8 y 3,6 logaritmos para recuento de aerobios mesófilos y enterobacterias, respectivamente. En ambos vegetales irradiados y no irradiados, no se detectó E. coli ni presencia de Salmonella spp. Durante el almacenamiento se observó un aumento de 1,6 - 1,7 logaritmos en ambos parámetros microbiológicos en las muestras no irradiadas. En los productos irradiados solo en apio se observó un aumento de 1,2 logaritmos en el recuento de aerobios mesófilos. En repollo el recuento de aerobios mesófilos se mantuvo sin variación en el tiempo, lo mismo se observó para el recuento de enterobacterias en ambos vegetales. No se detectaron diferencias significativas (p=0,05) en la calidad sensorial total, entre el control no irradiado y los productos irradiados, ni entre los días de almacenamiento

Efeito da radiação gama na sanitização da manga minimamente processada / Effect of the radiation gamma in the sanitation of the minimally processed mango

O objetivo do presente trabalho foi avaliar o efeito sanitizante da radiação gama na manga minimamente processada. Os frutos foram lavados em água, descascados, cortados manualmente em cubos de 3 x 3 cm e acondicionados em embalagens de polietileno terefltalato (tipo PET) Neoform, copos de plástico transparante (250ml) e saco plástico (0,6 micras) a vácuo. A seguir foram irradiados na EMBRARAD nas doses T1 (testemunha), T2 (0,1 kGy), T3 (0,2 kGy), T4 (0,3 kGy), T5 (0,4 kGy) e T6 (0,5 kGy), e armazenados a 5º C com 85 por cento de umidade relativa. A cada dois dias foi avaliada a incidência de coliformes, microrganismos mesófilos, psicrotróficos, bolores e leveduras. Pelos resultados obtidos, pôde-se verificar, após 10 dias de armazenamento, que os frutos com as doses de 0,4 e 0,5 kGy, armazenados em embalagem PET e copo plástico, apresentaram menores quantidades de mesófilos, psicrotróficos, bolores e leveduras, enquanto os frutos da testemunha apresentaram grande quantidades de mesófilos e psicrotróficos, bolores e leveduras, sendo considerados impróprios para o consumo no quinto dia de conservação. Logo, pode-se concluir que a radiação gama nas doses de 0,4 e 0,5 kGy foi efetiva no tratamento a manga minimamente processada.

Radioactivity and foods.

The purpose of this article is to describe and contrast two relationships between radiation and food--on the one hand, beneficial preservation of food by controlled exposure to ionizing radiation; and, on the other, contamination of food by accidental incorporation of radioactive nuclides within the food itself. In food irradiation, electrons or electromagnetic radiation is used to destroy microorganisms and insects or prevent seed germination. The economic advantages and health benefits of sterilizing food in this manner are clear, and numerous studies have confirmed that under strictly controlled conditions no undersirable changes or induced radioactivity is produced in the irradiated food. An altogether different situation is presented by exposure of food animals and farming areas to radioactive materials, as occurred after the major Soviet nuclear reactor accident at Chenobyl. This article furnishes the basic information needed to understand the nature of food contamination associated with that event and describes the work of international organizations seeking to establish appropriate safe limits for levels of radioactivity in foods.

Keeping food safe from harmful germs

The health of people depends to a large extent on the food they eat. Keeping food safe from harmful germs and their toxic products is therefore an important problem, which over the years has engaged the attention of various WHO expert committees concerned with different aspects of food hygiene. The latest report of the WHO Expert Committee on the microbiological aspects of food hygiene which met in Geneva in March 1976 (with the participation of FAO), has recently been published and it describes the microbiological agents of food-borne disease and the microbiological hazards in relation to foods. The article below, which is adapted from the second part of the Report, describes the microbiological hazards related to food processing, handling and storage, population movements, tourism, etc., as well as the measures available to control them