Sara Shamim,Zhenting Wu,Yuling Tang,Jingru Jia,Chunju Liu,Haiou Wang,Fangcheng Zheng,Long Ba
This study investigated the transformations of lemon flavedo tissues during freeze-drying based on high-resolution X-ray micro-computed tomography ( μ- CT) and confocal laser scanning microscopy (CLSM). Contrast-enhanced segmentation, traversal statistic algorithmic analysis, and 3D visualization of lemon peel texture are studied. To avoid pseudo-imaging caused by precipitation of contrast enhancer, low concentration cesium iodide was used to improve X-ray contrast and decrease enlarged inter-cellular region. X-ray μ-CT showed the precipitation of contrast enhancers at the intercellular boundary after freeze-drying. The grayscale thresholding method was presented as the most suitable segmentation method for detecting cell walls due to the high noise level caused by low contrast enhancer concentration in the reconstructed images. The faster water loss at the primary drying stage caused the disintegration of oil glands and induced high porosity of 0.7 % in fresh to 0.84 % in 0.5 h freeze-dried. The results suggest that noise filtering based on voxel statistics provides an efficient approach for the inter and intra-cellular microstructural analysis of excessively watery plant tissues with low contrast enhancer concentration.
Inspired by the citrus oil gland and cuticular wax, a multifunctional material that stably and continuously released the carvacrol and provided physical defenses was developed to address issues of fresh-cut fruits to microbial infestation and moisture loss. The results confirmed that low molecular weight and loose structure of starch nanoparticles prepared by the ultrasound-assisted Fenton system were preferable for octenyl succinic anhydride modification compared to native starch, achieving a higher degree of substitution (increased by 18.59 %), utilizing in preparing nanoemulsions (NEs) for encapsulating carvacrol (at 5 % level: 81.58 %). Furthermore, the NEs-based gelatin (G) film improved with surface hydrophobic modification by myristic acid (MA) successfully replicated the citrus oil gland and cuticular wax, providing superior antioxidant (enhanced by 3–4 times) and antimicrobial properties (95.99 % and 84.97 % against Staphylococcus aureus and Escherichia coli respectively), as well as the exceptional UV shielding (nearly 0 transmittance in the UV region), mechanical (72 % increase in tensile strength), and hydrophobic (WCA 133.63°). Moreover, the 5%NE-G@MA film inhibited foodborne microbial growth (reduced by 50 %) and water loss (controlled below 15 %), extending the shelf life of fresh-cut navel orange and kiwi. Thus, the multifunctional film was a potential shield for preserving perishable fresh-cut products.
危险品化学品经营许可证（带存储）