To meet the challenge of microbial contamination of food, smart packaging materials with active controlled-release functions have become a research hotspot. In this study, a humidity-responsive antimicrobial composite film was constructed by introducing cinnamaldehyde@β-cyclodextrin inclusion complexes (CIN@β-CD ICs) into a konjac glucomannan/polyvinyl alcohol/lithium chloride (KGM/PVA/LiCl) matrix. Characterization results showed that the CIN@β-CD ICs formed a dense structure through hydrogen bonding, which enhanced the thermal stability, mechanical strength (tensile strength: 20.83 MPa) and surface hydrophilicity (water contact angle < 60°) of the film. The film acted as a humidity-triggered release system for CIN, enabling controlled antimicrobial delivery: at high humidity (98% RH), the film rapidly swelled and accelerated the release of CIN, with a cumulative release rate of 87.29% over 7 days, whereas the release slowed significantly at low humidity (43% RH). The antimicrobial activity of the released CIN was strongly influenced by ambient humidity, with the effect enhanced under high humidity conditions. It is noteworthy that the film containing 0.2% ICs exhibited the optimal antimicrobial performance among the formulations studied. This study elucidates a mechanism for humidity-triggered release through multicomponent synergism, which provides a feasible strategy for the design of environmentally friendly, smart packaging materials with high antimicrobial activity.
L. vannamei has become one of the most productive species. However, it is susceptible to microbial contamination during fishing, transportation, and storage, which can lead to spoilage and quality deterioration. This study investigates the relationship between changes in the proteome of Litopenaeus vannamei (L. vannamei) muscle and quality characteristics during low-temperature storage using the tandem mass spectrometry technology of quantitative proteomics strategy. The differential expression of proteins under cold storage (4 °C, CS), partial slight freezing (−3 °C, PFS), and frozen storage (−18 °C, FS) conditions was compared with the fresh group (CK), resulting in 1572 proteins identified as differentially expressed. The purpose of this research is to identify potential biochemical markers by analyzing quality changes and relative differential proteins through searches in the UniProt database, Gene Ontology database, and Genome Encyclopedia. Correlation analysis revealed that seven DEPs were significantly related to physical and chemical indicators. Bioinformatics analysis demonstrated that most DEPs are involved in binding proteins, metabolic enzymes, and protein turnover. Additionally, some DEPs were identified as potential biomarkers for muscle decline. These findings contribute to understanding the mechanism of freshness decline in L. vannamei under low-temperature storage and the changes in muscle proteome.
A KGM/CMC/PVA film loaded with a hydroxypropy-β-cyclodextrin/hesperetin (HP-β-CD/HES) inclusion complex was developed for strawberry preservation. The inclusion complex showed an encapsulation efficiency of 70.41 ± 4.01%. Loading the inclusion complex enhanced the barrier and bioactive properties of the films. At the better loading level (KCP-HH3, 1.5%), the film provided nearly complete UV shielding at 200–350 nm and showed a transmittance of approximately 21% at 800 nm. Relative to KCP, KCP-HH3 exhibited lower water vapor permeability (0.69 ± 0.06 g·mm/(m2·h·kPa)) and oxygen permeability (0.066 ± 0.006 g·mm/(m2·h·kPa)). The cumulative HES release from KCP-HH3 reached 82.43 ± 2.19% after 7 days at 98% relative humidity. KCP-HH3 scavenged 78.19 ± 3.71% of DPPH radicals and 88.89 ± 4.30% of ABTS radicals. It also inhibited Escherichia coli (91.18 ± 2.99%), Staphylococcus aureus (79.21 ± 3.45%), and Aspergillus niger (92.85 ± 2.75%). This highest-loading formulation delivered the best overall strawberry-preservation performance. After 12 days of storage, strawberries packaged with KCP-HH3 showed higher firmness (0.89 ± 0.04 N) and total soluble solids (7.96 ± 0.21%), as well as lower weight loss (14.30 ± 0.40%), than the polyethylene control, which showed a firmness of 0.42 ± 0.05 N, total soluble solids of 6.22 ± 0.20%, and weight loss of 16.36 ± 0.66%. These results support the potential of HP-β-CD/HES-loaded KCP films as biodegradable active packaging for fruit preservation.