Application of Gelatin Composite Coating in Pork Quality Preservation during Storage and Mechanism of Gelatin Composite Coating on Pork Flavor

Gelatin coating is an effective way to prolong the shelf life of meat products. Aiming at solving the problem of flavor deterioration during the storage of pork at room temperature, pork coating technology was developed to preserve the pork at 25 °C, and the comprehensive sensory analysis of vision, touch, smell, and taste was used to study the effect of coating on preservation of pork flavor. Herein, uncoated (control) and coated pork samples (including gelatin coating and gelatin coating incorporated with ginger essential oil) were analyzed to investigate the integrity of pork periodically during storage at 25 °C for weight loss, color, texture (springiness, chewiness, cohesiveness, gumminess, and hardness), microstructure, odor (electronic nose), taste (electronic tongue), volatile flavor substance, and taste ingredients. The results suggested that ginger essential oil (GEO) gelatin coating and gelatin coating can effectively inhibit the loss of water dispersion and slow down the oxidation reaction, coating treatments could significantly (p < 0.05) retarded the weight loss of pork slices, with values of 20.19%, 15.95%, 13.12% for uncoated, gelatin coated, and GEO-gelatin coated samples during 24 h of storage, respectively. Compared with control group, the color, texture, smell, and taste evaluations demonstrated that coating treatments had improved sensory and texture attributes during the storage period. Furthermore, the comprehensive results from the physical property assays (especially the texture), morphological assay and volatile odor assays showed that the GEO-fish gelatin composite coating had better preservation effect on pork flavor than the fish gelatin coating. The study suggests that the gelatin composite coating could be developed as a prospective active packaging to preserve pork meat at room temperature.

Adding Kaffir Lime (Citrus hystrix) Leaf Essential Oil to Gelatin Coating for Extending the Shelf Life of Red Snapper Fillet

Red Snappers contain high content protein and water which makes them highly perishable. However, they are widely processed into the fillet. One of the disadvantages of filleting is the short shelf life due to the high water content turning the fillets into an ideal media for bacteria. The edible coating protects the meat from perishability by reducing the water vapor, aroma, and lipid migration. One of the potential protein sources for coating is gelatin. The essential oil content that has a role in inhibiting bacterial growth is citronellal. The present study aimed to determine the effects of adding Kaffir limes (Citrus hystrix) leaf essential oil to a gelatin coating on the shelf life of red snappers’ fillet. An experiment was conducted using a completely randomized design with four treatment groups based on the concentration of Citrus hystrix essential oil and five replications (n = 3 per group). In this regard, the treatments were named P0 (0% of Citrus hystrix), P1 (1% of Citrus hystrix), P2 (1.5% of Citrus hystrix), and P3 (2% of Citrus hystrix). The investigated parameters included total plate count, sensory quality, and acidity. Data analysis was performed using ANOVA followed by Duncan’s multiple range test. The results showed that the addition of 1.5% and 2% Citrus hystrix essential oil decreased the number of bacteria, and led to a higher sensory quality. In conclusion, The addition of Citrus hystrix essential oil in the gelatin-coating process can be used as a method of processing the fishery products to extend the shelf life of red snappers’ fillet at room temperature and inhibit bacterial growth.

Coating of Polystyrene Surface with REDV-Gelatin Conjugate for Selective Isolation of Endothelial Cells

Endothelial cells (EC), which line the internal surface of blood vessels, play various essential roles in controlling vascular function. The mouse is an important animal model for the study of vascular biology and cardiovascular diseases. However, the isolation of primary EC from the murine aorta is challenging because they are readily contaminated by smooth muscle cells (SMC). A previous study developed a simple method to isolate murine EC from SMC. By taking advantage of the differential sedimentation rate between the two cells, the EC was selectively enriched with collagen-coated polystyrene surfaces. Our study further improved this method by introducing a biomimetic peptide REDV (Arg-Glu-Asp-Val), which may bind specifically to EC but not to SMC or fibroblasts. Firstly, REDV-gelatin conjugate was synthesized by using the amine-to-sulfhydryl crosslinker SMCC. REDV-gelatin coating was then prepared on polystyrene surfaces, and their affinities to EC and SMC were subsequently investigated. Fluorescence microscopy and flow cytometric analysis showed that EC adhesion to the gelatin coating was significantly promoted by REDV peptide conjugation. Moreover, cell migration assay and cell viability assay also showed that the conjugation of REDV does not affect EC migration, and this coating did not show cytotoxicity against EC. This gelatin-REDV coating provides a cost-effective and straightforward tool for isolating EC from SMC, which may facilitate in vitro investigations of EC from mice.

Development of Gelatin-Coated Microspheres for Novel Bioink Design

A major challenge in tissue engineering is the formation of vasculature in tissue and organs. Recent studies have shown that positively charged microspheres promote vascularization, while also supporting the controlled release of bioactive molecules. This study investigated the development of gelatin-coated pectin microspheres for incorporation into a novel bioink. Electrospray was used to produce the microspheres. The process was optimized using Design-Expert® software. Microspheres underwent gelatin coating and EDC catalysis modifications. The results showed that the concentration of pectin solution impacted roundness and uniformity primarily, while flow rate affected size most significantly. The optimal gelatin concentration for microsphere coating was determined to be 0.75%, and gelatin coating led to a positively charged surface. When incorporated into bioink, the microspheres did not significantly alter viscosity, and they distributed evenly in bioink. These microspheres show great promise for incorporation into bioink for tissue engineering applications.