Evaluation of Factors Affecting Barrier, Mechanical and Optical Properties of Pectin‐based Films Using Response Surface Methodology

Abstract

Emulsion coatings were formulated and films were developed using pectin as the basic structural component. Preliminary experiments were carried out to determine the proper type and concentration of pectin, lipid and plasticizers in the film. The effects of pectin, beeswax and sorbitol concentration on water vapor permeability (WVP), mechanical properties and opacity of the films were evaluated using the response surface methodology. WVP increased by pectin and sorbitol concentration and was decreased by beeswax concentration. Mechanical properties were mainly affected by pectin and sorbitol concentration. Increasing the amount of pectin and decreasing the sorbitol concentration increased tensile strength (TS) and modulus of elasticity (EM), while elongation at break (EB) increased by increasing both pectin and sorbitol concentration. Beeswax was the most influential factor that affected opacity, which increased with increasing beeswax concentration. Models developed for WVP, EB, EM and opacity had high coefficient of multiple determination (R2) values (>0.87) and significant F values. The model for TS had a slightly lower R2 of 0.81. PRACTICAL APPLICATIONS This research examined the preparation of pectin‐based edible films, providing an understanding of the main functionalities of these coatings. This film can help retain moisture and restrict its movement. Moisture levels in foods are critical for maintaining freshness, controlling microbial growth and providing texture. This film can control water activity, preventing either moisture loss or uptake. It can protect food from physical injuries. Since so many formulations were designed, based on the use of the film one can select each type of formulation that works best for the specific application. It can potentially limit fat migration, provide a barrier to gas, help to trap flavor and aroma, and carry and present antioxidants or antimicrobials. This article will be of value to anyone working with products where edible films have potential applications and particularly to technical personnel and product developers who wish to understand the potential of edible film and coating technology.

Mechanical and water vapor permeability properties of biodegradables films based on methylcellulose, glucomannan, pectin and gelatin

“…Turhan and Şahbaz (2004) worked with different methylcellulose concentrations and observed that the higher the concentration, the higher the TS values and the film elongation, referred to concentrations that led to good polysaccharide solubilization and good film-forming solution spreading on the plate. The same tendency was also observed by Maftoonazad, Ramaswamy and Marcotte (2007) for high methoxyl pectin-based films plasticized with sorbitol. In the present research, low polysaccharide concentrations (0.75% and 1%) were used because higher concentrations made it difficult to blend and spread the film-forming solution onto the plate, mainly due to the high viscosity of glucomannan.…”

“…Pectin is a polysaccharide rich in D-galacturonic acid that is mainly obtained from citric peels or apple skin (MAY, 1997) and it may have high or low level of esterification degree; it is also used for films production (MAFTOONAZAD; RAMASWAMY; MARCOTTE, 2007;LIU et al, 2007).…”

Efecto del método de extracción en las características químicas y físicas del mucílago del nopal (Opuntia ficus-índica) y estudio de su aplicación como recubrimiento comestible.

“…La incorporación de lípidos supone pérdidas de brillo por la aparición de partículas grasas en la superficie, resultado de los procesos de floculación, coalescencia y cremado de los glóbulos grasos durante el secado de la película (Trezza y Krochta, 2000;Villalobos et al, 2005, Maftoonazad et al, 2007a. La apariencia (brillo, transparencia, color, opacidad) depende de la naturaleza del componente formador de la matriz del film, pero está muy afectada por la presencia de componentes no miscibles que sufren los procesos de desestabilización mencionados durante la formación del la película.…”

“…El área bajo la curva se define como la opacidad de la muestra en nm (Maftoonazad, et al, 2007a). Este parámetro puede dar indicios indirectos de la estructura del film: estructuras rugosas, generalmente son más opacas.…”

“…Maftoonazad et al (2007a), fueron elaborados mezclando la pectina con sorbitol y cera de abeja. Estos autores señalan que la permeabilidad al vapor de agua se ve incrementada con la concentración de pectina y sorbitol y decrece con la cera de abeja.…”