Navegando por Palavras-chave "Climacteric fruit"

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    Sistemas de embalagens ativas biodegradáveis para adsorção de etileno de frutos climatéricos
    (Universidade Federal de São Paulo, 2018-04-19) Soares, Thalita Rehder Pellegrina [UNIFESP]; Yoshida, Cristiana Maria Pedroso [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Active packaging for fruit preservation can prolong storage time, maintaining the nutritional composition and its physical integrity. This project aims to develop a new and sustainable active packaging material to adsorb the ethylene phytohormone, based on the ethylene gas adsorbents incorporation into chitosan coating Kraft paper and to study the stability of climacteric fruits packed in this packaging material. The application potential of this active packaging is to delay the ripening process of climacteric fruits. The system consists of the interaction of chitosan, a natural polymer from the discard of the fishing industry and a material capable of adsorbing the phytohormone ethylene. The project was divided into three major steps. First, the impregnation of silver in the adsorbent material (NaY zeolite or activated carbon) in the proportions of 5% and 10% was performed. Ethylene and nitrogen adsorption isotherms were determined. The zeolite impregnated with 10% silver was chosen for the Kraft paper coating, which is based on the best performance in adsorption of ethylene. In the second step, a factorial design 22 was performed to delineate the coating conditions of the Kraft paper, with the independent variables: chitosan concentration (1-2% w/w) and zeolite concentration (0.2-1.2% w/w). The chitosan/zeolite solutions were mechanically molded on sheets of paper and dried (120oC/2 min). The coated active papers were characterized by grammage, water vapor permeability, water absorption capacity (Teste Cobb), Taber stiffness, ethylene adsorption capacity and BET surface area. The paper coated with 2% of chitosan and 1.2% of zeolite presented a decrease in the water absorption capacity, maintenance, increase the stiffness, and it was observed the best performance for the ethylene adsorption. In the third stage, the efficiency of the active packaging material was evaluated for a climacteric fruit (cherry tomato).Weight loss, pH, texture, total solids, titratable acidity, phenolic compounds, and carotenoids were assessed during 30 days at 25 ± 2oC. The tomatoes conditioned in active coating presented a reduction of weight loss and maintenance the texture, indicating the characteristic of the adsorption capacity of ethylene gas.