Quick-dissolvable heat-sealable edible films made from orange peel powder and guar gum for instant beverage packaging

Abstract

Water-soluble films provide convenience, notably in scenarios requiring single-dose or on-the-go packaging, such as dissolvable sachets for individual servings of beverages, effectively minimising excess packaging waste. The main aim of this study was to create edible films that are water-soluble and heat-sealable by utilising a blend of guar gum and orange peel powder. The study investigated the impact of varying orange peel powder content on guar gum edible films’ properties. Physical (thickness, moisture content, swelling index, density, solubility), optical (colour, opacity, light transmittance), and barrier (water vapour transmission rate, water vapour permeability) properties of the films with different concentrations of orange peel powder were evaluated. Moreover, within the scope of utilising these films for packaging dry instant beverages, they were heat-sealed to form pouches and then filled with dry orange peel powder to evaluate their ability to dissolve instantly. As the orange peel powder content in the films increased, thickness, density, and colour parameters such as redness, yellowness, ΔE, chroma, hue angle, and browning index also increased, resulting in more thick, vivid colours and significant colour changes. Conversely, moisture content, swelling index, and light transmittance decreased with higher orange peel levels, impacting the films' textural properties and rendering them more opaque for better protection against light, oxygen, and heat, essential for extending food product shelf life. Moreover, solubility increased as the orange peel content increased, indicating greater water interaction facilitated by the extract's potential plasticising effect.