Application of Bacterial Cellulose Packaging Film Produced via Glycerol-Based In Situ Cultivation for Tomato Preservation

Abstract

This study aimed to investigate the relationship between bacterial cellulose (BC) productivity and its film characteristics produced by adding glycerol to the Hestrin-Schramm (HS) medium, and applying it to tomato preservation. The BC productivity after 9 days of culture with the addition of 1–4% glycerol was at least 1.5 times greater than that of the glycerol-free control. Compared with those of the BC films produced in the HS medium without glycerol, the average pore size (APS) and water vapour transmittance rate (WVTR) of the BC films produced by adding 1–4% glycerol decreased, whereas their tensile strength (TS) and elongation at break (EAB) increased. In addition, BC productivity exhibited linear regression relationships with the following film characteristics: APS, WVTR, TS, and EAB. Compared with no packaging, BC film packaging resulted in a lower weight loss percentage, greater microbial barrier capacity, and delayed skin shrinkage in tomatoes. It also significantly improved the freshness of cracked tomatoes. Furthermore, BC film packaging produced via 1% glycerol-based in situ cultivation achieved the optimal preservation effect on tomatoes due to its comparatively small APS of 12.2 nm and minimum WVTR of 267 g/m²/day. When the resulting BC film was applied to preserve noncracked and cracked tomatoes, the weight loss percentages were 15.7% and 35.8%, respectively, and the microbial barrier capacities were 67.5% and 70.9%, respectively. Our findings demonstrate that BC films have considerable application potential in food packaging.