Edible hydrosoluble sachets produced with food by-products and natural additives

In this work, edible films were produced from orange pectin and broken rice (food by-products), combined with different natural additives, namely orange oil, zinc oxide, rice husk (RH) and calcium acetate (CA). The films obtained were fully characterized, presenting similar colour, opacity, thickness and thermal properties. Water contact angles (WCA) ranged from 55 to 85º; water vapor sorption (WVS) between 17.0 and 32.5% (w/w); with a maximum water vapor permeability (WVP) of 14.52×10−11 g.m−1.s−1.Pa−1; Young's modulus between 0.88 and 3.0 GPa; tensile strength (TS) ranging from 6.0 to 19.0 MPa; elongation at break between 0.88 and 3.0%, and almost complete dissolution in water at 60 °C after 15 min. The WCA and mechanical properties of the films were compared with non-commercial and commercial biodegradable films. Orange pectin was the raw material that most influenced the films' properties. PCA (pectin and calcium acetate) and POO1.0RH (pectin, orange oil and rice husk) films showed the best mechanical and barrier properties, being applied as hydrosoluble sachets for white sugar. The organoleptic and physicochemical properties of the sachets were evaluated through sensory analysis and a 12-week shelf-life experiment, respectively. A high level of acceptability was obtained for the sugar sachets, with their physical structure and appearance practically unchanged throughout the tested shelf-life. Edible films obtained from these food by-products and natural additives were shown to be promising alternatives to synthetic sachets for use as sustainable food packaging.