Incorporação de paládio em adsorventes em revestimento de embalagens ativas de papel Kraft para adsorção do fitohormônio (etileno) no acondicionamento de frutos climatéricos
Data
2020
Autores
Ochi, Deise 
Orientadores
Silva, Classius Ferreira da
Tipo
Dissertação de mestrado
Título da Revista
ISSN da Revista
Título de Volume
Resumo
Com o aumento mundial de consumo de frutas e hortaliças, a agroindústria brasileira tem o desafio de trazer ao consumidor produtos frescos e seguros. A dificuldade, entretanto, reside na curta vida de prateleira de produtos hortifrúti. Uma das formas de estender a duração desses alimentos é controlando o gás etileno (C2H4), um fitohormônio que estimula o amadurecimento e acelera a senescência dos hortifrúti. Esse controle pode ser feito por embalagens que contenham compostos capazes de remover esse gás do meio. O presente trabalho, dividido em três etapas, teve como objetivo desenvolver um novo sistema sustentável de embalagem ativa aplicando um revestimento, de quitosana contendo um adsorvente modificado com paládio, em folhas de papel Kraft e realizar um estudo de estabilidade do fruto climatérico (tomate cereja) acondicionado neste material de embalagem. Na etapa 1, o carvão ativado em pó e a zeólita Y foram impregnados com 5% e 10% Paládio (m/m). Com base principalmente em isotermas de adsorção de etileno, foi selecionada a zeólita contendo 5% Paládio (m/m) como melhor adsorvedor de etileno para ser aplicado na Etapa 2, no revestimento do papel Kraft. As variáveis estudadas foram teor de quitosana e de adsorvente. Os sistemas Kraft-quitosana-adsorvente foram caracterizados, e o papel Kraft revestido com quitosana a 0,2% (m/m) e a zeólita a 1,2% (m/m) foi selecionado baseado na capacidade de adsorção de etileno e maquinabilidade. Na Etapa 3, cartuchos foram desenvolvidos com o material ativo para acondicionar o tomate cereja (Solanun lycopersicum var. cerasiforme). O sistema de embalagem ativa manteve C2H4 na menor quantidade comparado aos outros sistemas avaliados. Em relação aos tomates cereja acondicionados na embalagem ativa da Etapa 2, houve redução na velocidade de amadurecimento, constatado pelos resultados de acidez titulável, sólidos totais solúveis, β-caroteno
With the worldwide increase in consumption of fruits and vegetables, Brazilian agribusiness has the challenge of bringing fresh and safe products to the consumer. The difficulty, however, lies in the short shelf life of produce. A method to extend the duration of these foods is by controlling ethylene gas (C2H4), a phytohormone that stimulates ripening and accelerates the senescence of fruit and vegetables. This control can be done by packaging containing compounds capable of removing this gas from the medium. The present work, divided into three stages, aimed at the development of a new sustainable active packaging system by applying a chitosan coating containing a modified palladium adsorbent on Kraft paper sheets and carrying out a stability study of a climacteric fruit (cherry tomato) contained in this packaging material. In step 1, powdered activated carbon and zeolite Y were impregnated with 5% and 10% Pd (w/w). Based mainly on ethylene adsorption isotherms, zeolite containing 5% Pd was selected as the best ethylene adsorber to be applied in Step 2, in the coating of Kraft paper. In Step 2, the studied variables were chitosan and adsorbent content. Kraft-chitosan-adsorbent systems were characterized, and Kraft paper coated with 0.2% (w/w) chitosan and 1.2% (w/w) of impregnated zeolite was selected based on the adsorption capacity of ethylene and machinability. In step 3, cartridges were developed with the active material to store the cherry tomatoes (Solanun lycopersicum var. cerasifome). The active packaging system kept C2H4 in the lowest amount compared to the other evaluated systems. Concerning the cherry tomatoes stored in the active system of Step 2, there was a reduction in the ripening speed, evidenced by the results of titratable acidity, total soluble solids, β-carotene.
With the worldwide increase in consumption of fruits and vegetables, Brazilian agribusiness has the challenge of bringing fresh and safe products to the consumer. The difficulty, however, lies in the short shelf life of produce. A method to extend the duration of these foods is by controlling ethylene gas (C2H4), a phytohormone that stimulates ripening and accelerates the senescence of fruit and vegetables. This control can be done by packaging containing compounds capable of removing this gas from the medium. The present work, divided into three stages, aimed at the development of a new sustainable active packaging system by applying a chitosan coating containing a modified palladium adsorbent on Kraft paper sheets and carrying out a stability study of a climacteric fruit (cherry tomato) contained in this packaging material. In step 1, powdered activated carbon and zeolite Y were impregnated with 5% and 10% Pd (w/w). Based mainly on ethylene adsorption isotherms, zeolite containing 5% Pd was selected as the best ethylene adsorber to be applied in Step 2, in the coating of Kraft paper. In Step 2, the studied variables were chitosan and adsorbent content. Kraft-chitosan-adsorbent systems were characterized, and Kraft paper coated with 0.2% (w/w) chitosan and 1.2% (w/w) of impregnated zeolite was selected based on the adsorption capacity of ethylene and machinability. In step 3, cartridges were developed with the active material to store the cherry tomatoes (Solanun lycopersicum var. cerasifome). The active packaging system kept C2H4 in the lowest amount compared to the other evaluated systems. Concerning the cherry tomatoes stored in the active system of Step 2, there was a reduction in the ripening speed, evidenced by the results of titratable acidity, total soluble solids, β-carotene.