The role of bacterial nanocellulose in tailoring the tack, mechanical properties, and water sensitivity of transparent edible juice-based films.

Abstract

In recent years, fruit- and vegetable-based films have attracted growing interest as sustainable edible packaging materials. However, formulations prepared exclusively from juices or purées often exhibit limited cohesiveness, poor mechanical performance, high moisture sensitivity, and excessive tack; therefore, binders and reinforcing agents are frequently required to improve performance and promote their practical use. In this work, transparent edible films were prepared from pear juice and pregelatinized starch, incorporating different contents of bacterial nanocellulose (BNC) as a nanoscale reinforcing agent. Film-forming dispersions were prepared at room temperature and processed by solvent casting. The resulting films were evaluated in terms of optical properties, tack, morphology, mechanical behavior, and water-related properties. BNC incorporation significantly improved several of these characteristics (e.g. tack reduction up to 58%, tensile strength increase up to 425%, and water uptake decrease up to 34%), particularly evidencing its ability to structure juice-based film matrices, improve film performance, and reduce tack without compromising transparency. These findings highlight the potential of BNC as a versatile additive for tailoring key properties of the produced materials.