Kang Tu

Optical nondestructive evaluation has become an indispensable tool for quality assessment in the food industry. Revealing light propagation mechanisms in multilayered fruit and vegetable tissues improves detection model accuracy and robustness. In fact, most natural and processed fruit and vegetable materials inherently exhibit layered structures, leading to inevitable deviations in optical signals interpretation and quality prediction. The complex structure and heterogeneous composition of fruit and vegetable matrices pose great challenges to light–tissue interaction analysis. This review summarizes the layer‐specific differences in optical properties based on structural and compositional heterogeneity of fruit and vegetable matrices, using representative cases of other food matrices for comparison. It further addresses light propagation in multilayered fruit and vegetable tissues together with research on the optimization of detection parameters. Finally, a unified framework is proposed that integrates physicochemical properties, optical properties, and photon transport simulations to achieve mechanism‐guided optimization for nondestructive detection. Notably, the advances of Monte Carlo (MC) simulation empowered by artificial intelligence (AI) are highlighted in denoising, accelerating computation, and improving prediction accuracy. AI‐assisted MC simulation provides support for the efficient and high‐precision prediction of light propagation in multilayer tissues, and lays a solid foundation for the progress of food photonics.

Essential oils are difficult to disperse in hydrophilic films and may separate or volatilize during processing. We prepared chitosan quaternary ammonium salt/propolis films containing a TEMPO-oxidized cellulose nanofibril (TOCNF)/nisin-stabilized Pickering emulsion loaded with oregano essential oil. Two independent formulation variables were examined: the nisin fraction in the TOCNF/nisin particles (0–35% of particle mass) was first screened to select the emulsion stabilizer composition, whereas the selected TNO emulsion was subsequently added at 20%, 30%, 40%, or 50% (v/v) of the initial film-forming solution. At 25% nisin, encapsulation efficiency reached 88.0%, and the polydispersity index was 0.15, so this formulation was used in the films. As emulsion loading increased, the films became lighter and opacity fell from 19.75 to 4.81 A mm⁻¹. HCP/TNO30 reached a tensile strength of 45.18 MPa, but elongation at break decreased from 65.35% to 28.11% across the series. Water vapor and oxygen permeability were lowest at 40% loading. HCP/TNO50 had the highest radical-scavenging and antibacterial activities. It also reduced weight loss and quality deterioration during 12 days of green cherry tomato storage. No loading optimized every property. Mechanical strength and barrier performance peaked at 30% and 40%, respectively, while active preservation continued to improve up to 50%.

To overcome the limitations of conventional biopolymer films and reduce reliance on petroleum-based plastics, a nacre-inspired film was developed via 3D printing. During printing process, shear-induced alignment of mica flakes was achieved within a sodium alginate/xanthan gum matrix. Additionally, zinc oxide nanoparticles (ZnO NPs) were incorporated to achieve a synergistic reinforcement effect. Structural analysis revealed that the mica flakes within the film exhibited an oriented distribution, with ZnO NPs uniformly embedded in the interlayer voids, and hydrogen bonding assisted in forming a dense network of the components. Performance testing showed that the tensile strength rose from 13.8 MPa to 62.9 MPa. Improvements in water resistance and thermal stability were also observed. Furthermore, the material exhibited outstanding comprehensive protective properties, including a low water vapor permeability value of 7.587 × 10⁻¹¹ g·m/m²·Pa·s, an ultraviolet blocking rate of 99.37% at a wavelength of 280 nm, and the ability to completely inhibit target bacterial strains, while also possessing good biodegradability and recyclability. Shelf-life tests indicated that the film fabricated in this work could notably prolong the shelf life of strawberries. Biocompatibility test results indicated that the film was safe and non-toxic, and showed no significant cytotoxicity.