Efeito da radiação gama sobre o conteúdo de tocoferóis em produtos naturais e industrializados e avaliação sensorial

Abstract

Vitamin E content, the percentage of activity retention and the sensory characteristics were analyzed in samples of vitamin E rich foods: pecan nuts, whole grain cookies and a fortified powder formula irradiated with 1 and 3kGy of 60 Co gamma radiation. For the vitamin E determination (as -tocopherol equivalents) three different samples lots were employed using the colorimetric method standardized by the Instituto Adolfo Lutz of Sao Paulo. For sensory analysis, the Multiple Comparison or Control Difference Test was used for all products, comparing the irradiated samples to the non-irradiated controls and measuring the difference rate in total terms, concerning appearance, odor, texture and flavor, in a category scale of 9 points, ranging from 1 = no difference to 9 = extreme difference to the control. The experimental outline employed was that of randomized complete blocks design, in two consecutive sessions. The obtained data were submitted to variance analysis, ANOVA, and means comparison by Dunnett test, at 5% significance. The results show that there was no E vitamin loss in the pecan nuts, whole grain cookies and powder food samples, irradiated with 1 and 3 kGy doses. With regard to the sensory analysis, the 3kGy gamma irradiation produced significant changes in the sensory properties of pecan nuts for the attributes: appearance, odor, texture and flavor. The 1kGy dose did not cause a significant difference for these attributes. Concerning the sensory analysis of whole grain cookies and fortified powder food, significant differences were observed in all the irradiated products, although the difference grades were significantly low, compared to those of the non-irradiated samples, especially when 1kGy dose was applied.TABELA 1-Alimentos considerados fontes de vitamina E (Ohio St. Univ., 2004). Pães, Cereais e outros grãos Cereais matinais, Cereais fortificados Germe de trigo Frutas Maçã assada Damasco Nectarina crua Pêssego Hortaliças Acelga Couve Mostarda Abóbora Nabo Carnes, Aves e substitutos Fígado, frango, ou peru Peixes Marisco em conserva Corvina cozida ou assada Cavala em conserva Salmão assado ou grelhado Vieira assada ou cozida Camarão cozido ou assado Nozes e sementes Amêndoa Nozes Avelã Amendoim Manteiga de amendoim