Filme à base de mucilagem de quiabo e amido de milho para aplicação em alimentos

Abstract

The development and application of packaging made from biopolymers has received special attention. Films or coatings obtained from natural sources have significant advantages over conventional petroleum-derived packaging in terms of their biodegradability and environmental effects. Among the materials used in film making and food coatings are carbohydrates, plant and animal proteins and lipids. Currently, new material alternatives have been studied as a way of increasing the variety of sources available for this purpose and as a way of enhancing existing biodiversity. The okra (Abelmoschus esculentus) is a well known plant in Brazil and produces the fruits popularly known as okra. Much appreciated in cooking and with outstanding biological activities (antidiabetic, antioxidant and cholesterol regulating agent), okra stands out for the richness of mineral and vitamin components, property of forming gels and their applications in the food and pharmaceutical industries, where the The mucilage obtained from this fruit can be used as a thickening, stabilizing and binding agent. Thus, this work aimed to develop films with okra mucilage and cornstarch, to study their characteristics regarding mechanical, thermal and barrier properties, as well as their toxicity. The properties of okra mucilage precipitated material were also evaluated for their thermal characteristics, as well as their influence on the film structure. The experiment followed the Central Compound Rotational Design (CCRD), varying concentrations of corn starch and glycerol (independent variables), obtaining 11 treatments. The results were submitted to statistical analysis. The films presented compact and uniform structure, low Water Vapor Permeability (1.32 to 2.84 g.mm/kPa.h.m2), low water solubility (about 15%), good thermal and mechanical properties, presenting a higher resistance to traction when compared to films made with starch only. Moreover, they presented good swelling capacity (about 95%), which is associated with the sensitivity of the structure to different pH ranges, such as those used in the experiment. The filmogenic solution did not result in any toxicological response when administered to animals, which ensures its use for film making and application. The precipitated material of okra mucilage presented characteristics similar to those of long chain polysaccharides and good thermal properties. Okra mucilage proved to be effective in improving film properties, possibly associated with quality intermolecular bonds established between the mucilage constituents, corn starch and glycerol, the plasticizer used in the formulation. The design formulation F9 presented the best overall results in relation to the evaluated attributes. Thus, okra and cornstarch mucilage films have the potential to be used as food packaging material