Desarrollo de películas de almidón oxidado de cáscaras de plátano verde y aceite esencial de cáscaras de naranja

Abstract

Environmental pollution caused by disposable plastics has generated a global crisis, driving the search for biodegradable alternatives. This experimental work addresses this problematic development of biodegradable films from starch extracted from green banana peels, an abundant agricultural residue, and essential oil from orange peels. The starch extraction process was carried out using wet grinding and avoiding enzymatic browning with citric acid (C6H8O7), obtaining a yield of 4.5166±1.3614%. The chemical modification used was the oxidation method, applied to starches extracted from banana peels; for the formulation of oxidized starches, it was started with a standard concentration of 0.5% NaClO (v/v) with active chlorine and reaction times of 30 and 45 minutes, demonstrating that the reaction increased the carboxyl groups (p<0.05). The functional properties analyzed such as water absorption index (WAI), water solubility index (WSI) and swelling power (PH), analyzed in oxidized starches, tend to increase as reaction times increase (p<0.05). The chemical composition of the starches studied registered an increase in the percentages of ash, moisture (p<0.05); but the opposite is shown in the percentages of proteins, fats, fibers and carbohydrates (p<0.05). The formulation of the films was developed through a multilevel factorial design, of 2², developed in three blocks, using the Statgraphics 19 program, obtaining a total of 12 treatments with two levels of glycerol of 2% w/w and 3% w/w and AE. of orange peels with two levels of (0.3% w/w and 0.6% w/w); keeping the starch and water contents constant; The proposed response variables were %Humidity, %Solubility and PVA. The percentage of essential oil (EO) from orange peel residues and its interaction with the percentage of glycerol plasticizer, tend to decrease the % of humidity, %solubility and PVA of the films studied (p<0.05); while the percentage of glycerol alone tends to increase the percentages of the response variables studied in the films obtained (p<0.05). The optimal values for the formulation of films with glycerol and EO from orange peel that facilitate minimizing the % of humidity and % solubility were 2%w/w and 0.69%w/w, respectively and for PVA, the optimal values that allow minimizing this response variable were 3%w/w and 0.29%w/w; these percentages reduce the physical properties of humidity and solubility; as well as the barrier properties of PVA. Finally, the adjusted model of the response variables obtained for %humidity, %solubility and PVA indicate an R² of 99.7822%, 99.5528% and 98.2412% and the adjusted R² of 99.6008%, 99.1802% and 96.7755% respectively and their regression models obtained were, (%Humidity= 3.41667 + 4.46333 * %Glycerol + 7.13333 * %AE6.05556 * %Glycerol * %AE), (%Solubility= 0.517533 + 0.181033 * %Glycerol - 0.0412222 * %AE - 0.226333 * lycerol * %AE) and (%PVA= -0.000403716 + 0.000211928 * %Glycerol + 0.000670489 * %AE - 0.000343409 * %Glycerol * %AE).