Curvas de secagem, propriedades tecnológicas e aplicação pós-colheita de filmes biodegradáveis de fécula de inhame (Dioscorea ssp.) e glicerol

Abstract

The package is has main function to protect them against mechanical damage and moisture loss. The use of plastic film provides a strong environmental impact because it is an exhaustible raw materials and no biodegradable. Thus there is great interest in the development of biofilms edible or biologically degradable. However, are not found in the literature about the kinetics of drying of these materials. Despite having excellent properties of strength and flexibility, the use of plastic film provides a strong environmental impact due to their composition coming from the oil that besides being an exhaustible raw material is not biodegradable. After harvesting, the tomato is presented as a very perishable fruit. The edible coating is a physical barrier used to reduce the weight loss caused by water loss and to avoid contamination by external agents and to avoid an early ripening. This study aims to evaluate the chemical and functional characteristics of yam starch extracted with oxalic acid and oxalate of ammonia and compares them with the characteristics of conventional starches; Obtain model the drying curves of the filmogenic solutions the temperatures of 25, 30, 35, 40 and 45°C with different amounts of starch and glycerol of the drying process; Study and optimize the effect of the starch and plasticizer and process temperature on the mechanical properties in puncture tests and tensile tests, and also in tests of solubility and permeability in films made from starch yam and glycerol from a central composite delineameto using the response surface method and; Evaluated the maintenance of quality in cherry tomatoes topped with edible films made from yam starch and glycerol. To determine the effect of hedges, there was analysis of weight loss, soluble solids, acidity and firmness for 18 days beyond the final and initial characterization of total polyphenols, antioxidant activity and lycopene content in tomatoes coated. Concluded that the yam starch extracted with oxalic acid and ammonium oxalate has a significant amount of protein and sugars, and low solubility in cold water, is more stable to heat and agitation, has intermediate retrogradation tendency in addition to low power swelling and solubility in cold oil; The models for the two phases (time constant and decreasing drying) have adapted well toall the drying temperatures and concentrations of components, with P-values below10%. The interaction between starch content and temperature influenced theparameters of drying rate in the period constant and the values of the diffusion coefficient. The percentage of starch influenced the initial moisture contents while the critical moisture varied depending on the starch content and temperature during film formation of the solutions. The amount of glycerol did not affect any parameter analyzed; The mechanical properties of yam starch and glycerol films were highly influenced by the plasticizer. Properties of deformation and strain had higher values for the interaction between lower temperatures and higher levels of glycerol occurred. The power was in effect break the contrary, as the level of glycerol decreased and increased drying temperature increased the independent variable. The tension was influenced by the interaction between starch and glycerol, so that the most important factor involved was the plasticizer, which at lower levels increased the tensile strength of the films. The solubility was influenced by the interaction between starch and glycerol so that higher levels of starch and glycerol increase the solubility of the films.For the permeability was no significant