Regina Celi Cavestré Coneglian

EFEITO DA IRRADIAÇÃO IONIZANTE gama NA QUALIDADE PÓS-COLHEITA DE CENOURAS (Daucus carota L.) cv. NANTES

The goal of this work was to evaluate the effect of g irradiation on the post harvest physical and chemical characteristics of cv. Nantes carrots. According to the Family Budget Survey (FBS, 1991) carried out in the Brazilian Southeast, within the roots and tubers group, carrots are widely consumed. It is also well known that the carrot is one of the best sources of provitamin A (a and b-carotene). Doses of 0.25, 0.50, 0.75 and 1.0kgy of g ionizing irradiation, from a cesium source, in accordance with the maximum dose allowed by the FDA (1995), were used on the carrots. The different treatments and the control group were evaluated by analysing for pH, total soluble solids (TSS), total titratable acidity (TTA), TSS/TTA ratio, weight loss, hardness, colour, total carotenoid content, ascorbic acid concentration and volatiles. The variance analysis (F of the Fisher treatment) of the results showed no significant difference at the 5% level between the irradiated samples and the control group for most of the tests, except for the colour intensity, which faded with increase in the irradiation dose, total acidity and TSS/TTA ratio, which decreased due to the decrease in the organic acid concentration after harvest. The results show that the low dose irradiation process is very promising to maintain the quality of the product, being a good alternative to avoid post harvest losses.

Starch edible coating of papaya: effect on sensory characteristics

O revestimento de mamoes por Fecula de Mandioca (FM) e carboximetilamido (CMA) e uma alternativa que visa prolongar a vida de prateleira dos frutos. Este estudo avaliou o efeito de tres diferentes niveis de FM e CMA (1, 3 e 5%) nas caracteristicas sensoriais de mamao papaia durante o armazenamento. Nove provadores selecionados e treinados avaliaram 13 atributos sensoriais atraves do teste de comparacao multipla. Os atributos de aparencia e sabor dos mamoes tratados com FM e CMA foram comparados com a referencia (R - sem revestimento)usando escalas de nove pontos, as quais variaram de 1: menos intenso que R; 5: igual a R; 9: mais intenso que R. As amostras foram codificadas com numero de tres digitos e avaliadas com repeticao pelos provadores. Em geral, a aparencia dos frutos foi mais afetada que o sabor pelos revestimentos utilizados. Frutos revestidos a 3 e 5% de FM e CMA apresentaram coloracao verde por mais tempo, mas a 5% a cor foi menos uniforme no ultimo dia de avaliacao. Os revestimentos de FM a 3 e 5% conferiram maior brilho aos frutos. O CMA a 5% favoreceu a presenca de fungos e injurias na superficie no 14o dia de armazenamento. O revestimento de FM a 5% apresentou descascamento durante todo o periodo experimental. Alteracoes no sabor dos frutos foram percebidas aos 12o e 14o dias de armazenamento. Sabor menos caracteristico e gosto amargo foram identificados nos frutos revestidos por FM e CMA a 5% no 12o dia de armazenamento.

Testes sensoriais de aceitação da beterraba vermelha (Beta vulgaris ssp. vulgaris L.), cv. Early Wonder, minimamente processada e irradiada

Red beet (Early Wonder) was cultivated in an experimental area of the Department of Fitotecnia at the Institute of Agronomy at the Rural Federal University of Rio de Janeiro (UFRRJ). After harvest, the roots were minimally processed; packed; exposed to different doses of gamma radiation (0; 0.5; 1.0 and 1.5 kGy) and stored for 20 days at 8.0 °C. Sensory evaluations were performed 1; 9; 13 and 20 days after irradiation by 12 testers who rated the overall appearance and aroma on a hedonic scale. The results indicated that the irradiated samples remained within the limit of acceptance for 20 days. In addition, the aroma was found to be a more sensitive indicator of the effect of different doses of radiation to the acceptance of the product.