A New Protocol for Obtaining Mucilage and Biopolymeric Ecofilms From Cacti

Abstract

The objective was to produce an innovative biopolymeric ecofilm, using hydrotested and reused alcohol for mucilage extraction and incorporation of calcium lactate into the film. The mucilage of Nopalea cochenillifera (L.) Salm-Dyck was extracted with ethyl alcohol P.A. (99.8%) or reused alcohol after hydrodistillation (82%). Mucilage powder was hydrated (4% w/v), glycerol at a concentration of 60% and calcium lactate (0% and 2%) were added and the emulsion was then placed in the oven for 24 h to prepare the films. The innovation of this work was the recycling of the ethanol used to extract cactus mucilage in order to prepare ecofilms, which resulted in a more environmentally friendly production process. The industrial yield of mucilage extracted using distilled ethanol (1.3%) was lower than that of P.A. alcohol (3.3%). However, the mucilage extracted using distilled ethanol had a higher concentration of carbohydrates and phenolic compounds and lower levels of Na⁺ and K⁺, leading to reduced electrical conductivity. The biopolymeric ecofilm obtained was thinner (0.15 mm) and had lower solubility in water (43%) and moisture content (15%), greater transparency (12.65%) and higher tensile strength (12.91 MPa). The addition of calcium lactate in biopolymers decreased water solubility while increasing permeability and thickness. Furthermore, it enhanced the resistance and thermal stability of biopolymeric ecofilms. Thus, biopolymeric ecofilms of mucilage obtained showed potential for use in biofilms and edible coatings on fruits and vegetables, with a strong appeal for lower environmental impact and, consequently, being able to reduce manufacturing costs for the industry.