Extração de pectina das cascas de maracujá amarelo (Passiflora edulis f. flavicarpa) e aplicação na confecção de biofilmes compostos

• Autor(a) principal: Seixas, Fernanda Lini
• Data de Publicação: 2011
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Estadual de Maringá (RI-UEM)
• Texto Completo: http://repositorio.uem.br:8080/jspui/handle/1/3764
• topic: Extração de pectina - Casca de maracujá amarelo (Passiflora edulis f. flavicarpa); Biofilmes compostos - Casca de maracujá amarelo (Passiflora edulis f. flavicarpa); Engenharias; Engenharia Química

Pectin is a polysaccharide present in cell walls of plants and it's used industrially as a gelling agent or stabilizer. It can be extracted from the peels of yellow passion fruit, an abundant agro-industrial waste. The first part of this work aims to study the extraction of pectin with a maximum yield using acetic, nitric and tartaric acid. Through the conventional process of extraction and under microwave heating. The peels of passion fruit were dried and milled to obtain a flour to extract the pectin. The acid extraction was carried out under heating, using a ratio solid / solvent 1:50 (w/v). Subsequently, the pectins were isolated by precipitation in ethanol in volume ratio of 1:2 v/v. For the conventional process the parameters analyzed were: acid concentration, temperature and extraction time. A Box-Behnken experimental design was used. For this case, the highest yield was found for extraction with tartaric acid 24.18% under the conditions of pH 1.9, 80 ° C and 40 min. For nitric acid 14.10% under pH 1.9, 90 ° C and 20 min and for acetic acid 10.7% under the conditions of pH 2.1, 90 ° C and 20 min. Considering the extractions performed under microwave heating were analyzed the effects of power emitted by the equipment and the exposure time. This method resulted in higher yields with better properties and pectin (DE, molecular weight, uronic acid content). The highest yields were found for the wave's emitted power 627.9 W, 9 minutes of exposure and pH 2.0. Accordingly pectins extracted with nitric acid showed a 13.0% yield, high molecular weight, 82.3% uronic acids and a high degree of esterification (68.15%). Pectins obtained by the use of acetic acid showed a yield of 12.91%, high molecular weight, 80.5% uronic acids and a high degree of esterification (64.56%). The highest yields (30%) were obtained by the use of tartaric acid, however, the extracted pectin had some undesirable qualities, such as: low degree of esterification, low molecular weight and low content of uronic acid (58.5%). The main sugar constituents of the extracted pectin were arabinose, galactose and glucose. Rheograms pectin solutions (1 g/L) showed a Newtonian fluid behavior. The second part of this work proposes the use of commercial citrus in the formulation of biofilms. These materials were prepared from pectin and alginate and further characterized. The films were prepared by casting. The manufacturing process of the films consisted of two stages. First the alginate and pectin (1:1) were dissolved in water containing 0.04 g of CaCl2.2H2O/g macromolecule and 0.6 g glycerol/g macromolecule. The second stage (crosslinking complementary) consisted of immersing the films in 50 mL of a solution CaCl2.2H2O and glycerol, both with different concentrations, for 30 minutes. Was evaluated the effects of the plasticizer (glycerol 5, 7 and 10% v/v) and crosslinking agent (Ca++ 3, 5 and 7% w/v) on mechanical properties, water solubility, degree of swelling and permeability to water vapor in the biofilms. The films, with an average thickness of 0.07 mm, were attractive appearance, acceptable mechanical properties, moisture content around 20% and water solubility in the range of 32 to 55%. These films have a degree of swelling around 1.1 to 2.17. The water vapor permeability is moderate and the values are typical of hydro philic biofilms.