Jussara Carvalho de Moura Della Torre

Inactivation by ionizing radiation of Salmonella Enteritidis, Salmonella Infantis, and Vibrio parahaemolyticus in oysters (Crassostrea brasiliana)

Irradiation is considered one of the most efficient technological processes for the reduction of microorganisms in food. It can be used to improve the safety of food products, and to extend their shelf lives. Oysters are considered one of the most important vehicles for pathogenic bacteria because of their feeding characteristics. The aim of this study was to evaluate the influence of a gamma radiation process on high levels of Salmonella Enteritidis, Salmonella Infantis, and Vibrio parahaemolyticus incorporated by oysters (Crassostrea brasiliana), as well as the effects of the process on the survival of the oysters and on their sensory attributes. The oysters were exposed to gamma radiation (60Co) in doses ranging from 0.5 to 3.0 kGy. A dose of 3.0 kGy was generally sufficient to reduce the level of Salmonella serotypes by 5 to 6 log10 units. A dose of 1.0 kGy was sufficient to produce a 6-log10 reduction in the level of V. parahaemolyticus. The highest irradiation dose did not kill the oysters or affect their sensory attributes. Hence, a dose of 3.0 kGy can be considered effective in inactivating Salmonella and V. parahaemolyticus in oysters without changing their odor, flavor, or appearance.

Perfil sensorial e aceitação de suco de laranja pasteurizado minimamente processado

Onze provadores selecionados e treinados avaliaram a aparencia, aroma e sabor de amostras de suco de laranja natural processado em nove diferentes condicoes de temperatura de pasteurizacao - tempo de retencao, e compararam com amostras do suco de laranja natural nao processado, utilizando a Analise Descritiva Quantitativa (ADQ). Teste de aceitacao pelo consumidor foi conduzido em laboratorio, com cinquenta provadores nao treinados, utilizando as escalas: hedonica, intensidade de odor e sabor natural, e intencao de compra. Tanto os provadores, como os consumidores, receberam as amostras em cabines individuais iluminadas com luz vermelha, exceto para os testes de aparencia, que foram conduzidos sob a luz branca do dia. As amostras foram apresentadas segundo delineamento experimental de blocos completos casualizados com duas repeticoes e os resultados foram analisados aplicando a Analise de Variância (ANOVA). A ADQ mostrou que houve diferencas significativas em relacao a presenca de particulas, aroma e sabor natural de laranja, diminuindo a intensidade com o aumento do tempo de retencao. Entretanto, nao houve diferencas significativas entre as amostras do suco nao processado e do suco processado, em relacao a cor amarela, viscosidade percebida visualmente, odor e sabor fermentado, e sabor de oleo essencial. O teste de consumidor indicou que o suco de laranja natural processado sob a condicao mais severa (87,0°C/58,55s) foi melhor aceito, apresentou maior intensidade de aroma e sabor de laranja natural e revelou maior intencao de compra em relacao a um suco de laranja pasteurizado de marca comercial.

Influence of distillation time and sample mass on sulfur dioxide analysis in passion fruit juice through Monier-Williams method.

This study aimed to evaluate the effect of the distillation time and the sample mass on the total SO2 content in integral passion fruit juice (Passiflora sp). For the SO2 analysis, a modified version of the Monier-Williams method was used. In this experiment, the distillation time and the sample mass were reduced to half of the values proposed in the original method. The analyses were performed in triplicate for each distilling time x sample mass binomial, making a total of 12 tests, which were performed on the same day. The significance of the effects of the different distillation times and sample mass were evaluated by applying one-factor analysis of variance (ANOVA). For a 95% confidence limit, it was found that the proposed amendments to the distillation time, sample mass, and the interaction between distilling time x sample mass were not significant (p > 0.05) in determining the SO2 content in passion fruit juice. In view of the results that were obtained it was concluded that for integral passion fruit juice it was possible to reduce the distillation time and the sample mass in determining the SO2 content by the Monier-Williams method without affecting the result.