Xiong Chen

Recently, renewable biopolymers have gained growing attention as an alternative to petroleum-based materials in the packaging industry due to their eco-friendliness, biodegradability, and biocompatibility. This study introduces an innovative method for producing active films, which uses natural bacterial cellulose (BC) films as the matrix and incorporates (−)-Epigallocatechin-3-gallate (EGCG) through an immersion process. The incorporation of EGCG improves the barrier performance against oxygen and UV of the BC-based active films while preserving their tensile strength without compromising their opacity. More importantly, the active films exhibited significant antibacterial effects, with the efficacy increasing with the concentration of EGCG. Specifically, the diameters of the inhibition zones enlarged progressively against both S. aureus (from 13.88 to 16.25 mm, p < 0.05) and E. coli (from 12.38 to 14.13 mm). Correspondingly, the antibacterial rate of the active films increased from 61.4% to 80.61% (p < 0.05) against S. aureus and from 57.38% to 60.38% against E. coli. Additionally, the BC-based active films developed in this work exhibit excellent biodegradability, being capable of achieving complete biodegradation within 21 days of soil burial. This breakthrough exhibits considerable potential of BC-based active films as eco-friendly packaging materials, showing exceptional promise for sustainable active food packaging applications.

The cigar wrapper leaves (CWLs), as a symbol of the intrinsic quality and appearance of cigars, reflects the overall quality of the cigar. The Shaoxing-flavored T3 Jiuqu used in Shaoxing wine production contains a large number of high-quality microorganisms, such as molds and yeasts, which play a significant role in enhancing flavor and quality. Among these microorganisms, several positively promote the fermentation of CWLs. A dominant strain, S1, was isolated and identified from the T3 Jiuqu and inoculated into the fermentation of CWLs. Gas Chromatography-Mass Spectrometry (GC-MS) was employed to analyze the volatile aroma components in the CWLs. The results showed that the contents of substances such as Phenethyl alcohol, Dihydroactinidiolide, Sclareol, and Farnesyl acetone were significantly increased compared to pre-fermentation (NF) and the natural fermentation with only water (WF) group. Specifically, Phenethyl alcohol content increased by 261.63% compared to WF group during the same turning-over period, while Farnesyl acetone content increased by 144.99%. The proportions of sugars and nicotine also increased significantly. Metagenomic analysis of the microbial samples on the surface of CWLs revealed that inoculating S1 significantly improved and altered microbial community structure. At the phylum level, the proportion of Pseudomonadota increased dramatically to 17%, while the proportion of Uroviricotasharply decreased sharply from 9% to 0. At the genus level, the previously dominant Staphylococcus genus was replaced by a balanced coexistence of Pantoea, Enterobacter, Cronobacter, and Aspergillus. This balanced microbial distribution significantly improved the quality of the CWLs.