O objetivo desse trabalho foi verificar a viabilidade do uso de aparelho de microondas para a determinação do teor de umidade de grãos de milho. Nesse estudo foram utilizadas amostras de milho com teor de umidade na faixa de 7,33 a 22,28%. Equações de regressão linear foram determinadas correlacionando-se os valores de percentagem de água retirada após secagem no microondas e o teor de umidade determinado pelo método de estufa a 105oC ± 3o C por 24 horas. O tempo de permanência do produto no aparelho de microondas foi fixado em 45 segundos. Nas condições em que o experimento foi realizado, o aparelho de microondas mostrou ser uma alternativa viável para a determinação de umidade de grãos de milho.
The possibility of using a micro-wave oven as a rapid method for moisture determination of corn grain was verified, as well as the effects of different potencies on the moisture content of the grains. In this study corn samples with moisture contents in the range of 7,33 to 22,28% were used. Linear regression lines were determined by the relation of the values of percentage of water taken out after drying in the microwave and the moisture contents determinated by the oven official method (105°± 3°C/24 hours). The drying time of the product was fixed at 45seconds. In the conditions of this experiment, the microwave oven has shown to be a feasible alternative for a rapid determination of the corn moisture content

The relationships between fungal growth and ergosterol content and between aflatoxins B1 and B2 production and ergosterol content were verified in corn grains. In the first experiment, fungal growth and ergosterol content were monitored during incubation of corn grains presenting water activities of 0.85aw and 0.92aw at 25ºC over a period of 18 days. For the Taiúba variety, the fungi growth and ergosterol content increased more rapidly for 0.92aw than 0.85aw. Maximum ergosterol levels were 2.8 and 4.6 µg/g, respectively, for 0.85aw and 0.92aw. For the Cargill hybrid 606, a more pronounced increase in fungal growth was verified just at the end of the incubation period, mainly for 0.92aw when an acentuated increase in ergosterol content was also observed. Maximum ergosterol levels detected were 1.6 µg/g and 5.8 µg/g, respectively, for 0.85aw and 0.92aw. There was a significant correlation between ergosterol content and log of CFU g -1 for 0.92aw but not for 0.85 aw. In the second experiment, samples of corn grains of the Taiúba variety at 0.87aw and 0.95aw were inoculated with a toxigenic Aspergillus flavus strain and incubated at 25ºC. Ergosterol levels reached maximum values of 12.1 and 73.4 µg/g, respectively, for 0.87aw and 0.95aw. In both water activities, content aflatoxin B1 followed the same trend as ergosterol. For the aflatoxin B2 this trend was not observed. Ergosterol assay appears to be a useful test to measure fungal growth and to indicate the possibility of aflatoxin production in corn grains.

The application of technologies to extend the postharvest life of mangosteen fruit was studied and compared to storage at 25 °C/70-75%R.H (25 °C control treatment). The fruits were packed in expanded polystyrene (EPS) trays (5 fruits/tray). Five treatments were carried out at 13 °C/ 90-95% RH: application of carnauba wax coating, lecithin + CMC (carboxymethyl cellulose) coating, 50 µm LDPE (low density polyethylene) film coating, 13 µm PVC (Polyvinyl chloride), and non-coated sample (13 °C control treatment). Physicochemical analyses were performed twice a week. A statistical design was completely randomized with 8 repetitions for each treatment plus the control treatment. The results were submitted to variance analysis, and the averages compared by the Tukey test at 5% probability. Among the quality parameters analyzed, more significant differences were observed for weight loss, texture, and peel moisture content. The results showed that the maximum storage period for mangosteen at 25 °C is two weeks; while storage at13 °C can guarantee the conservation of this fruit for 25 days. Therefore, the treatment at 13 °C/90-95% RH without the use of coatings and films was more effective and economical.

RESUMO -o objetivo deste trabalho foi avaliar a aplicação de produtos alternativos e de refrigeração, com posterior aplicação de etileno, sobre a qualidade de ameixas 'Reubennel', a fim de prolongar o período de comercialização. Os produtos aplicados logo após a colheita foram: biomassa cítrica (Ecolife®)-150 mL (p.c.) 100 L -1 por 30 s; vapor de etanol -2 ml kg -1 por 2 h (20ºC/80%UR), e cloreto de cálcio (CaCl 2 ) -1% (p/v) por 10 min. Em seguida, os frutos foram armazenados a 0ºC/95%UR. Após 17 e 33 dias, três caixas de cada tratamento, com 40 frutos cada, foram removidas da câmara de refrigeração, sendo uma das caixas segregada para análises, enquanto as outras duas foram transferidas para 20 o C/85%UR por mais 4 dias. Destas caixas, uma de cada tratamento foi submetida à climatização, através da aplicação de etileno (100 uL l -1 , 72 h) em minicâmara (200 L). Procedeu-se à avaliação da qualidade dos frutos ao zero; 17; 17+4; 33 e 33+4 dias, através de análises físico-químicas, microbiológicas e sensoriais. Os resultados foram analisados estatisticamente, em delineamento experimental inteiramente casualizado para os produtos alternativos e em fatorial (4x2) para a combinação com a climatização. Concluiu-se que o tratamento pós-colheita das ameixas com vapor de etanol reduz a população microbiana, bem como proporciona incremento dos sólidos solúveis. as ameixas 'Reubennel' podem ser armazenadas por até 33 dias sob refrigeração (0ºC/95%UR), seguindo-se a climatização com etileno e, imediatamente, comercializadas. Termos para indexação: Prunus salicina, etileno, etanol, cloreto de cálcio, biomassa cítrica. PLUMS QUALITY CV. REUBENNEL AFTER TREATMENT WITH ALTERNATIVE PRODUCTS, COLD STORAGE AND CLIMATIZATIONABSTRACT -the purpose of this research was to evaluate the application of alternative products and refrigeration, with subsequent exposure to exogenous ethylene on quality of plums 'Reubennel', in order to prolong the marketing period. Products applied soon after harvest were: citric biomass (Ecolife ®) -150 ml (pc) 100 L -1 for 30 s; ethanol vapor -2 ml kg -1 , per 2 h (20°C/80% RH) and , calcium chloride (CaCl 2 ) -1% (w / v) for 10 min. Then, the fruits were stored at 0°C/95% RH. After 17 to 33 days, three boxes per treatment with 40 fruits each were removed from the cooling chamber, one of the boxes segregated for analysis, while the other two were transferred to 20 o C/85% RH for 4 more days. Of these boxes, one for each treatment was subjected to climatization through the application of ethylene (100 uL -1 ,72 h) in a mini-camera (200 L). We proceeded to evaluate the quality of the fruit at zero, 17, 17+4, 33, and 33+4 days, through physicalchemical, microbiological and sensory analysis. the results were analyzed statistically in a completely randomized design for alternative products and factorial (4x2) for the combination with the climatization. it was concluded that post-harvest treatment of plums with ethanol vapor reduces the microbial population as well as providing increased soluble solids. the 'R...

VILAR, S. B. O.; CASTRO, M. F. P. P. M.; SIGRIST, J. M. M.; ARAÚJO, A. J. B; SCHMIDT, F. L. Efeito do tratamento hidrotérmico associado ao etanol na qualidade de manga Tommy Atkins. Revista de Agricultura Neotropical, Cassilândia-MS, v. 2, n. 2, p. 1-8, abr./jun. 2015. ABSTRACT: Mango is a fruit of great expression in Brazilian exports; however, as phytosanitary limitation some importing countries require that mango receives hydrothermal treatment for the control of the fruit fly. The alternative use of ethanol in the control of microorganisms and pathogens in plants have also been studied. This study evaluated the effect of hydrothermal treatment and its association with 1% ethanol on the quality of mango cv. Tommy Atkins stored at 10°C/90% RH. Experiments were performed with 200 fruit in maturation stage 2, comparing the control treatment (mango washed, dried, and stored), the hydrothermal treatment without ethanol and combining the hydrothermal treatment with 1% ethanol. It was concluded that the mango quality parameters were not affected by hydrothermal bath or addition of ethanol. Ethanol associated with the hydrothermal treatment can be a practice to control pathogens in mango, without affecting the quality during storage.