In this study, we investigated the effect of microwave-assisted extraction (MAE) on the yield, structure, and properties of rabbit skin gelatin. Compared to water bath extraction gelatin, short-term (5-30 min) MAE gelatin had better gel properties, which formed gels at a slower rate due to destruction of more hydrogen bonds, but had more powerful triple helix-like structures after a sufficiently long maturity (16-18 h) since more high-molecular-weight subunits were retained. Scanning electron microscope showed that MAE could form numerous holes on the surface of gelatin. This study will be of great significance for high efficiency of gelatin extraction.

In this paper, the food-grade gelatin nanoparticles (GNPs) were prepared by a two-step desolvation method and using genipin as a cross-linker. The GNPs with narrow size distribution and good dispersion could be obtained only at pH 12. The effect of the genipin dosage (8–12 wt%) on the GNPs was systematically investigated. The results showed that the cross-linking degree of the GNPs increased with the increasing dosage of genipin, thus leading to a more obvious cross-linking morphology observed from scanning electron microscope (SEM). The obtained GNPs showed a good dispersibility with a size range of 386–438 nm. However, the GNPs cross-linked by 8 wt% genipin dosage revealed a relatively higher size because of the aggregation induced by hydrogen bond. The 10 wt% group had good thermal stability and storage stability. The optical microscopy results showed that the Pickering emulsions (30–50 vol% internal phase) stabilized by the GNPs had good uniformity and stability, even after 30 days of storage time, suggesting that the stable GNPs had great potential in food-grade Pickering emulsions.

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This study was carried out to investigate the changes in the microstructure and structural proteins (titin, nebulin, desmin and tropomyosin (TPM)) of mandarin fish muscle as well as the relationship between the structural proteins and the quality characteristics of fish muscle during post‐mortem storage and after cooking. During post‐mortem storage, titin was degraded initially, accompanied with an increase of the I‐band length. Subsequently, the degradation of desmin induced a gradual breakage of the myofibrils. The following degradation of nebulin accelerated the destruction of N2‐lines, which occurred with a slightly fuzzy Z‐disc. Finally, TPM began to degrade, and the remaining desmin was also degraded further. Principal component analysis (PCA) and correlation analysis indicated that the changes in the quality characteristics of fish muscle were intimately related to the degradation of structural proteins. Hence, these structural proteins could be the biomarkers to monitor the quality characteristics of fish muscle.

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