Biodegradable films of galactomannan: use in conservation fortress fruit.

• Autor(a) principal: Ed Carlos Morais dos Santos
• Data de Publicação: 2012
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UFC
• Texto Completo: http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=8319
• topic: Galactomananas, filmes biodegradÃveis, glicerol, tempo de prateleira; BIOQUIMICA

The fruit growers are adapting to changes in consumption patterns and increased demand from consumers about the quality of fresh fruits available. The market need to meet the demand from consumption centers, which are increasingly distant from the centers of production, makes it necessary to prolong the shelf life of fruits without these attributes lose their health protection as a result of natural aging process. Research aimed at developing new technologies for reducing post harvest losses are fundamental to the national economy, and minimize losses, increase competitiveness and seek to meet the qualities of an increasingly demanding mark et. Biodegradable films and edible coatings have received attention in recent years, mainly due to its potential application for preserving fruit. The objective of this work was to study the biodegradable films prepared from galactomannan of Caesalpinia pu lcherrima and glycerol aiming its use in the creation of packaging to increase shelf life of fruits. Initially we analyzed the effect of preparation conditions of films on the properties of barriers and found that both temperature and drying time cause a p ositive effect on the permeability to water vapor of these films, being chosen, so the temperature of 50 Â C and 12 hours as standard methodology for preparing the films. Then , we studied the influence of concentrations of galactomannan and glycerol on phy sical - chemical properties and found that the variables were statistically significant in all properties, highlighting that the glycerol had a positive influence on all tests, increasing concentration of glycerol provides increased studied property , probabl y due to its hygroscopic character. The increase in the concentration of galactomannan causes a decrease in absorption, moisture content and oxygen permeability and carbon dioxide. It was observed that temperature and relative humidity have a major influen ce on the barrier properties of the films, since the increase of these variables causes an increase in permeability to water vapor and oxygen. To understand how films behave in the face of mechanical stress, we studied the influence of the galactomannan an d glycerol on the mechanical properties and found that the thickness of the films increases with these variables and that the polysaccharide is responsible for increasing the tensile strength , puncture and tear strength of the films and the plasticizer has a positive influence on elongation and tear strength. After the knowledge of all the physico - chemical, mechanical and barrier properties and having the formulations which afforded us the desired properties optimized, we chose the formulation of GalGl y (0 . 4:1 . 0) (%, m: m) to test the performance of films for packaging to maintain the shelf life of sliced apples. It was observed that the apples they received the protection of the films showed the lowest respiration rate, weight loss 10% lower and lower level s of browning, brightness and color variation when compared with those who were not covered under the tested conditions. Thus, the films studied in this work have great potential for application in the packaging sector and contribute to increase the shelf life of fruits