Water sorption and water permeability properties of edible film made from potato peel waste

Abstract

The water sorption and permeability properties of edible film produced from potato peel waste was investigated under different levels of relative humidity (23, 33, 43, 57, 75% RH) and temperatures (5, 30, 50 °C). The water sorption behaviour and isotherms of the film were investigated by fitting water sorption data to the Peleg model and the Guggenheim, Anderson de Boer model (GAB model). The amount of moisture content, time required for the moisture content of the film to reach equilibrium, water sorption rate, and water sorption capacity increased when the relative humidity increased. The effect of temperature on moisture content, water sorption rate, water sorption capacity, and monolayer moisture content is complex and related to the water activity as well as the moisture content. Based on R 2 and RMSE values, the Peleg and GAB models were respectively determined as excellent models to predict the water sorption properties of the films, thus supporting the reliability of water sorption behaviour prediction. The water vapour transmission rate and water vapour permeability increased with an increase in relative humidity and temperature. The sorption and permeability properties of the film are worth investigation since the final application of the film as food packaging is ultimately dependent on these behaviours.

Tapioca starch films reinforced with microcrystalline cellulose for potential food packaging application

“…Among the packaging applications, food packaging represents the single largest element whereby demand for food packaging has been growing due to the increase in the number of world population. Nevertheless, this problem can be solved by replacing the non-degradable materials with biodegradable materials such as biopolymer (Dthman, 2014;Dthman et al, 2017a). Biopolymer is a polymer produced by living organism that consists of monomeric units that are covalently bonded, forming chain like molecules.…”

Water Sorption and Mechanical Properties of Starch/Chitosan Nanoparticle Films

“…At high relative humidity condition, water molecules were adsorbed into the films faster than the films stored at low relative humidity condition. This was due to the saturated water molecules at high relative humidity condition, thus increasing the rate of adsorption of water molecules in the surrounding into the films [31]. Furthermore, more time was needed for the moisture content of the films to reach equilibrium at high relative humidity than low relative humidity [22].…”

“…Note that saturated water molecules in the surrounding also lead to the longer time for the water sorption activity to reach equilibrium. Hence, the time required for the moisture content to reach equilibrium increases with increasing relative humidity [31].…”

“…Low value of k 1 indicates that the films exhibit a high initial water sorption rate [25] while low value of k 2 indicates that the films exhibit high water adsorption capacity [12]. Note that saturated water molecules in the surrounding also result in high kinetic energy, thus increasing the sorption of the water into the films [31]. This resulted to an increase in the rate of sorption (low k 1 ) and water adsorption capacity (low k 2 ) with an increase in relative humidity whereby the films absorbed faster and stored more water when kept at high relative humidity surroundings [12].…”

“…In terms of temperature, no specific trend of k 1 values with the change in temperature was observed for various levels of relative humidity. According to Othman et al [31], at any specific relative humidity, temperature increment may result to a reduction in water sorption. This was due to the high kinetic energy caused the water molecules to become unstable and escape from the binding sites in the films, thus reducing the water sorption rate.…”