Recent Advances in Sustainable Antimicrobial Food Packaging: Insights into Release Mechanisms, Design Strategies, and Applications in the Food Industry

Molecular mechanism underlying coencapsulating chrysophanol and hesperidin in octenylsuccinated β-glucan aggregates for improving their corelease and bioaccessibility

Chrysophanol and hesperidin are natural nutraceuticals that exhibit synergistic bioactivities, but their hydrophobicity limits their applications, and it is unclear whether coencapsulation can improve their solubility and release behaviors. The objective of this work was to coencapsulate chrysophanol and hesperidin by octenylsuccinated β-glucan aggregates (OSβG-Agg) and to reveal how coencapsulation improves their release and bioaccessibility. Mechanisms underlying the hypothesis of beneficial effects in coloading, corelease and bioaccessibility were revealed. The solubilization of OSβG-Agg was due to hydrogen-bonding among β-glucan moieties of OSβG and hydroxyl groups of chrysophanol and hesperidin and hydrophobic interactions among octenyl chains of OSβG and hydrophobic moieties of chrysophanol and hesperidin. Structural analyses confirmed the hypothesis that chrysophanol molecules were nearly embedded deeper into the interior of hydrophobic domains, and most of hesperidin molecules were incorporated into the exterior of the hydrophobic domains of OSβG-Agg due to the strength of these interactions, but they interacted in OSβG-Agg with a dense and compact structure rather than existing in isolation. The combined effects delayed their release and enhanced their bioaccessibility because of dynamic equilibrium between the favorable interactions and unfavorable structural erosion and relaxation of OSβG-Agg. Overall, OSβG-Agg is effective at codelivering hydrophobic phenolics for functional foods and pharmaceuticals.

Preparation of edible antibacterial films based on corn starch /carbon nanodots for bioactive food packaging

Packaging plays an important role in protecting food from environmental impacts. However, traditional petroleum-based packaging has difficulty in meeting the antimicrobial and antioxidant requirements of prepared foods. This study introduced carbon dots (CDs), prepared by using carrot as a precursor, into corn starch (CS) to construct a bio-friendly composite film with high freshness retention properties. The scavenging of DPPH radicals reached 92.77 % at a CDs concentration of 512 µg/mL, and the antimicrobial activity of CS/5% CDs against Escherichia coli and Staphylococcus aureus was increased to 99.9 %. Notably, the homogeneous doping of CDs creates a dense surface and high carbon content inside the film, which promotes the elasticity and thermal stability of the composite film. Finally, we encapsulated deep-fried meatballs in CS-CDs films. The results showed that the CS-CDs films effectively protected the quality of deep-fried meatballs, and have excellent potential for application in food preservation.

A sustainable packaging composite of waste paper and poly(butylene succinate-co-lactate) with high biodegradability

The challenge of global climate change has drawn people's attention to the issue of carbon emissions. Reducing the use of petroleum-derived materials and increasing the use of biodegradable materials is a current focus of research, especially in the packaging materials industry. This study focused on the use of environmentally friendly plastics and waste paper as the main materials for packaging films. Poly(butylene succinate-co-lactate) (PBSL) was modified with maleic anhydride (MA) to form a biobased compatibilizer (MPBSL), which was then blended with a mixture (WPS) of waste-paper powder (WP) and silica aerogel powder (SP) to form the designed composite (MPBSL/WPS). The modification of PBSL with MA improved interfacial adhesion between PBSL and WPS. The structure, thermal, and mechanical properties, water vapor/oxygen barrier, toxicity, freshness, and biodegradability of MPBSL/WPS films were evaluated. Compared with the PBSL/WP film, the MPBSL/WPS film exhibited increased tensile strength at break of 4-13.5 MPa, increased initial decomposition loss at 5 wt% of 14-35 °C, and decreased water/oxygen permeabilities of 18-105 cm3/m2·d·Pa. In the water absorption test, the MPBSL/WPS film displayed about 2-6 % lower water absorption than that of the PBSL/WP film. In the cytocompatibility test, both MPBSL/WPS and PBSL/WP membrane were nontoxic. In addition, compared with PBSL/WP film and the control, the MPBSL/WPS film significantly reduced moisture loss, extended the shelf life, and prevented microbial growth in vegetable and meat preservation tests. Both MPBSL/WPS and PBSL/WP films were biodegradable in a 60-day soil biodegradation test; the degradation rate was 50 % when the WP or WPS content was 40 wt%. Our findings indicate that the composites would be suitable for environmentally sustainable packaging materials.

Thermal-Driven Curcumin Release Film with Dual-Mode Synergistic Antibacterial Behavior for Efficient Tangerine Preservation

Antimicrobial packing showed great potential in extending the shelf life of food. However, developing a new biocomposite film with an intelligent and efficient antimicrobial performance is still desirable. Herein, a Fe-MoOx encapsulated with curcumin (Cur) filled chitosan-based composite film (CCF films) was prepared by solvent casting method. The total color differences of the CCF films were less than 30%, and satisfactory surface color, transparency, hydrophobicity, and thermal stability were also obtained. Besides, the UV-light/water/oxygen barrier capability and mechanical properties were enhanced with the incorporation of Cur@Fe-MoOx. Moreover, CCF films showed photothermal performance and thermal-controlled curcumin release ability, which endowed the CCF0.15 film with excellent antibacterial capability toward E. coli (≥99.95%) and S. aureus (≥99.96%) due to the synergistic antibacterial effect. Fe-MoOx exhibited high cell viability and less than 5% hemolysis even under the concentration of 500 μg mL-1. Based on those unique characteristics, the CCF0.15 film was chosen for tangerine preservation. The CCF0.15 film could prolong the shelf life of tangerine by at least 9 days compared with the unpacking group, and the tangerines could maintain the freshness characteristics over a 24 day storage period. Such thermal-mediated antibacterial film proposed by our work showed promising potential in food packaging.

Ions-Induced Alginate Gelation According to Elemental Analysis and a Combinatorial Approach

This study considers the potential of elemental analysis of polysaccharide ionotropic gels in elucidating the junction zones for different divalent cations. The developed algorithm ensures the correct separation of contributions from physically adsorbed and structure-forming ionic compounds, with the obtained results scaled to alginate C12 block. Possible versions of chain association into dimers and their subsequent integration into flat junction zones were analyzed within the framework of the "egg-box" model. The application of combinatorial analysis made it possible to derive theoretical relations to find the probability of various types of egg-box cell occurrences for alginate chains with arbitrary monomeric units ratio μ = M/G, which makes it possible to compare experimental data for alginates of different origins. Based on literature data and obtained chemical formulas, the possible correspondence of concrete biopolymer cells to those most preferable for filling by alkaline earth cations was established. The identified features of elemental composition suggest the formation of composite hydrated complexes with the participation of transition metal cations. The possibility of quantitatively assessing ordered secondary structures formed due to the physical sorption of ions and molecules from environment, correlating with the sorption capabilities of Me2+ alginate, was established.