Bioplástico de Quitosana /ágar - ágar incorporado com bacteriocina para aplicação como embalagem ativa

Abstract

This work aims to develop a bioplastic film from natural materials, with an environmentally friendly bias and the function of containing, protecting and prolonging the lifespan of a perishable food product. Two natural polymers were used, chitosan and agar-agar, and a low molecular weight plasticizer. The formulation was determined using the experimental design technique, evaluating the mechanical characteristics of the films, which are essential for handling the material as responses. After determining the composition of the films and to ensure active potential, purified bacteriocina extract produced by Lactobacillus sakei and isolated from a food matrix by the research group was added. The physical, mechanical and microbiological characterization was performed for the film with and without extract, to study the interaction of the compounds present in the filmogenic matrix. The results obtained indicate that he thicknesses varied between 0.048±0.009 and 0.099±0.015 mm, the water vapor permeability between 1.49x10-13±0.97 and 2.04x10-13±0.28kg m-1Pa-1s -1, ruptura stress between 11.08±2.33 and 13.57±2.17 MPa, elongation between 15.51±2.87 to 18.66±2.44%, the solubility between 10.28 ± 1.038 to 20.97 ± 2.958%, the swelling property between 35.75±3.245 to 67.45±0.967%, the water from 15.85±2.705 to 20.93±0.325% and transmittance from 37.57±3.81 to 86.37±1.42%. Infrared spectroscopy, surface analysis and thermogravimetric analysis found that all the constituents of the film-forming solution interacted. The release of the active compound was gradual during the time of contact with the simulator solution, having between the third and the fifth day the release peaks. The reduction of the microbial development showed effect during all the analyzed time. The in vitro, in situ and microatmosphere antibacterial responses showed the effectiveness of the active film against the test microbiota, showing a reduction of 2.62 log UFC / g directly in the food. It is concluded that the film has active capacity with characteristics that favor acting as a barrier film, and increasing the microbiological stability of the food.