RESUMO
Abstract This research aims to determine the efficiency of chitosan and xanthan gum films in conservation of croaker fillets kept in refrigeration for 9 days. Proximal composition, loss of mass, color, pH, TVB-N (Total Volatile Bases) and microbiological profile were assessed. The films were prepared with chitosan and xanthan gum in varying mass proportions 100:0, m:m (C100XG0); 60:40, m:m (C60XG40); 50:50, m:m (C50XG50). They presented the respective values for moisture content, water solubility, thickness and water vapor permeability: 24.59%, 19.50%, 0.086 mm and 11.45gm-1.s-1.Pa-1for C100XG0; 24.58%; 20.27%, 0.091 mm and 10.41 gm-1.s-1.Pa-1for C60XG40; 22.11%, 22.06%, 0.089 mm and 10.68 gm-1.s-1.Pa-1 forC50XG50.The films were made in small bags format capable to hold about 20 g of fish fillets. A control sample was prepared in parallel, using polyethylene bags under the same storage conditions. The results showed that the chitosan films combined with xanthan gum had excellent antimicrobial properties, capable of preserving the quality of chilled fish fillets during the studied period, since it inhibited the growth of Staphylococcus coagulase-positive, Salmonella spp and coliforms at 45 ° C. Mass loss of the croaker fillets was not significantly affected by xanthan gum addition to the films. On the other hand, xanthan gum addition affected pH and color parameters of the corvina fillets. It was also verified that the combination of these two polymers promoted the reduction of N-BVT, being the C50XG50 film that presented the best response.
Assuntos
Animais , Xanthomonas/química , Embalagem de Alimentos/métodos , Quitosana/química , Peixes/microbiologia , Conservação de Alimentos/métodos , Polissacarídeos Bacterianos/química , Anti-InfecciososRESUMO
Fish is a highly perishable food by their complex chemical composition, pH close to neutrality, high water activity and high metabolic activity of the microbiota. The sanitary conditions in the marketing of fish must be included within the appropriate standards of hygiene, to ensure product quality and consumer health. The sanitary quality of the fish begins to catch, continuing during handling, processing, storage and marketing. The present study evaluated the microbiological quality of fish sold in the street market in Palmas - TO. Counts were made of fecal coliforms, Staphylococcus coagulase positive and Salmonella in 25g in differentfish species marketed in street market in Palmas, Tocantins. The gold and peacock showed high counts of fecal coliform bacteria, indicating poor sanitary conditions. Snapper, golden peacock, had reduced counts of Staphylococcus coagulase positive, indicating that procedures appropriate hygienic and sanitary. Snapper and golden showed no presence of Salmonella sp. in 25g, indicating adequate sanitary conditions. In peacock was verified the presence of Salmonella in 25g, indicating inadequate sanitary conditions. The marketing of fish in street market in poor sanitary conditions may represent a potential danger to the health of consumers. (AU)
O peixe é um alimento altamente perecível, pela sua composição química complexa, pH próximo à neutralidade, elevada atividade de água e pela alta atividade metabólica da microbiota. As condições higienicossanitárias na comercialização de peixes devem estar inseri das dentro dos padrões adequados de higiene, para garantir a qualidade dos produtos e a saúde dos consumidores. A qualidade higienicossanitária do peixe se inicia na captura, continuando durante o manuseio, processamento, armazenamento e comercialização. O presente estudo avaliou a qualidade microbiológica de peixes comercializados nas feiras livres de Palmas - TO. Foram realizadas contagens de coliformes fecais, Staphylococcus coagulase positiva e pesquisa de Salmonella em 25g, em peixes de diferentes espécies comercializados nas feiras livres de Palmas-TO. O dourado e o tucunaré apresentaram contagens elevadas de coliformes fecais, indicando condições higienicossanitárias deficientes. Caranha, dourado e tucunaré, apresentaram contagens reduzidas de Staphylococcus coagulase positiva, indicando a aplicação de procedimentos higienicossanitários adequados. Caranha e dourado não evidenciaram presença de Salmonella sp. em 25g, indicando condições higienicossanitárias adequadas. Em tucunaré foi verificada a presença de Salmonella em 25g, indicando condições higienicossanitárias inadequadas. A comercialização de peixes em feiras livres em condições higienicossanitárias deficientes pode representar um perigo potencial à saúde dos consumidores. (AU)