Desarrollo de un biofilm a partir de almidón de cáscara de yuca nativa de la provincia de Manabí

Abstract

This study exposes the elaboration of biofilm from cassava shell starch, cultivated in the Manabí province, the film that has been developed with the addition of glycerol as plasticizer. The variation of pH has been evaluated to know the optimum level required to achieve the best physicochemical and optical characteristics, as well as an adequate biodegradation time. Thickness, density, humidity, color, water solubility, base solubility, acid solubility, and biodegradability were carried out to evaluate the films. The result should that films with pH 7.5 to 11.5 are suitable for packaging alkaline foods, neutral and acid with a percentage of degradation after 31 days between 10.35 ± 0.30% to 30.56 ± 3.93%. On the contrary, it was established that films with pH 4.7 and 6.5 are not suitable for food packaging due to their rapid disintegration when it enter in contact with alkaline or near-neutral substances. To evaluate the optical characteristics, the CIELAB test was carried out, obtaining as a result that pH increase is directly proportional to the color difference and inversely proportional to the opacity, this information will be useful in the film designing for food use, due color is an essential parameter that predominates in the appearance of the product and according to this in the consumer acceptability, with the results obtained in this section we have the necessary information to select the color of the film based on the pH measurements. The biodegradability of the films was also evaluated based on the pH, according to the results obtained, total biodegradation is projected between the 3rd to 7th months with the optimal pH´s for the development of a film for food packaging (7.5 to 11.5), this complies with the estipulate in the "Proyecto de Ley Orgánica para la Racionalización, Reutilización y Reducción de Plásticos de un Solo Uso en el Comercio" that considers a polymer as a biodegradable when its total decomposition does not exceed 24 months. Thus, with the data obtained according to the pH´s values, it is possible to know the approximate time of biodegradation in a developed film. This work provides the opportunity to carry out new research on the use of matrices considered as waste and that can be used as raw material for the production of biopolymers, future research with this matrix should focus on the mechanical properties and scaling at the industrial level through techniques as the blowing, that is adequate for polymers with average density of 1.484 g/cc, value that exceeds that established for high-density polyethylene (max 0.96 g/cc), which would result in excellent resistance mechanics.