La agroindustria ecuatoriana representa un sector de participación importante para la economía. Su funcionamiento genera residuos que dada su composición y posibilidad de procesamiento, se convierte en un material de interés para ser aprovechado como materia prima en la elaboración de bioplásticos. La disponibilidad del residuo depende del volumen generado, razón por la cual se estimó la cantidad que produce la agroindustria del país, usando una metodología preestablecida que parte del promedio anual de cultivos, la porción de producción asignada al procesamiento industrial, la tasa de generación de residuos y otros usos competitivos. Se estimó que anualmente la agroindustria del país genera cerca de 2200 millones de kilogramos, los cuales en su mayoría están compuestos por almidón o recursos lignocelulosos, que con transformaciones físicas, químicas o biotecnológicas, pueden emplearse como materia prima, material de relleno o precursor de los bioplásticos.

Objective: To obtain biofilms from starch and cellulose present in the avocado (Persea americana) peel and seed. Materials and methods: The starch characterization included humidity, gelatinization temperature, paste clarity, absorption index, solubility index, swelling power, amylose, amylopectin, amount, and starch yield. Five mixtures were made with 3 g of starch, 5 mL of 30 % NaOH (w/v), 3 g of cellulose, and different proportions for glycerin: 2 g; 2.5 g; 3 g; 3.5 g; 4 g, and PVA: 2 g, 3 g, 4 g, 5 g, and 6 g. Films were formed on acrylic plates, using the casting method. The bioplastic was characterized in terms of moisture, solubility in water, density, thickness, biodegradability, stress, deformation, and modulus of elasticity. Results and discusión: The addition of cellulose to the mixture does not contribute to film formation, unlike PVA which did. The film had the best physical appearance with a mixture of 2 g of glycerin and 6 g of PVA. The bioplastic characterization was 23.43 % humidity, 39.39 % for water solubility, 1.52 g/cm3 density, 0.58 mm thickness, 21.03 % weight loss for the biodegradability test, 1.53 MPa for tension, 21.25 % deformation, and 10,04 MPa for the modulus of elasticity. Conclusions: The bioplastic obtained did not show the resistance of traditional plastic. However, the results obtained serve as a starting point for the realization of other formulations, aimed at producing a bioplastic capable of competing with its synthetic relatives.

The problems caused by synthetic plastics have motivated the use of other materials. This research consisted of taking advantage of the banana peel and cellulose from the pseudostem of this plant to obtain a bioplastic. Dry milling was applied to extract the flour and an acid-alkaline treatment for the cellulose. The elaboration of the thermoplastic material did with a mixture design where fixed amounts of shell flour (5 g), 15% NaOH (5 mL), and water (4 mL), varying the concentrations of the plasticizers, which were glycerol and sorbitol. In two of the formulations, was added as filler 0,5 g of cellulose. The bioplastic obtained was characterized according to its thickness, water vapor permeability (WVP), tension force (TF), break time (bt), and biodegradability. The type of plasticizer and the cellulose content did not affect the thickness of the bioplastic, but it did affect the WVP, TF, and bt. WVP decreases when glycerin is used and increases with the addition of cellulose. The best result for WVP was 1,83 x 10-9 g/Pa.s.m in the formulation where only was used glycerol, while the best values for TF, bt, and biodegradability were 2,4 MPa, 17 seconds, and 37,77%, respectively, with 75% sorbitol and 25% glycerol. Expanding the study of the best formulations would allow their use as a replacement for synthetic plastics.

El plástico, pese a ser un material de gran utilidad dada su múltiple aplicación, representa un problema ambiental por acumulación en el ecosistema principalmente marino y por su largo tiempo de degradación. Ante esta situación se han desarrollado materiales sustitutos como es el caso de bioplásticos, los cuales usan recursos renovables como materias primas siendo una de ellas el almidón. El trabajo que a continuación se presenta corresponde a un proyecto realizado dentro de la asignatura Balance de Masa, con la cual se buscó extraer almidón de los granos de maíz para luego emplearlo con glicerina y ácido acético en la elaboración de una lámina de bioplástico. Una vez realizados los procesos correspondientes se obtuvo un rendimiento de 5,72% inferior respecto a otros casos estudiados y un porcentaje de degradación del bioplástico de 89,40% para un periodo de 42 días de experimentación, siendo este último bastante satisfactorio si se compara con los requerimientos establecidos en normativas internacionales para este tipo de materiales.