Structure of Hyla rabbit skin gelatin as affected by microwave-assisted extraction

Abstract

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.

Extraction of Gelatin from Different Parts of Gallus Gallus Domesticus

“…The values of L* and b* of CFGal and CBG were lower compare with CFGac, CHGac, and CHGal. The lower L* values were probably due to the longer pre-treatment time as mention by [24]. According to [25], a longer pre-treatment time will result in non-enzymatic browning leading to a decrease of L* values.…”

Application of Green Technology in Gelatin Extraction: A Review

“…Since the heat was produced within the solvent medium in a microwave oven, it could have caused a drying effect on the surface of the duck feet that retarded gelatin extraction, resulting in a low gelatin yield [68]. The higher gelatin yield was obtained from duck skin, with a recovery of 28.51% [29], and the lowest was from rabbit skin (6.44%) [69]. Gelatin [68] studied the effects of extraction by a microwave oven, water bath, and pressure cooker on the quality of duck-feet gelatin.…”

“…Since the heat was produced within the solvent medium in a microwave oven, it could have caused a drying effect on the surface of the duck feet that retarded gelatin extraction, resulting in a low gelatin yield [68]. The higher gelatin yield was obtained from duck skin, with a recovery of 28.51% [29], and the lowest was from rabbit skin (6.44%) [69]. Gelatin extracted from duck skin, duck feet, and rabbit skin recorded a lower yield than the conventional method, which was 11.71% in duck skin, 51.83% in duck feet, and 7.50% in rabbit skin.…”

“…Gelatin extracted from duck skin, duck feet, and rabbit skin recorded a lower yield than the conventional method, which was 11.71% in duck skin, 51.83% in duck feet, and 7.50% in rabbit skin. However, Liu et al (2019) [69] reported that the gelatin yield increased with increased extraction time from 60 to 90 min at 65 • C using 500 W. However, the yield was still considered low when compared with conventional water-bath extraction.…”

“…Higher frequency might not affect the yield, as gelatin yield from duck skin using the lowest microwave frequency (200 W) was 28.52% compared to duck feet (310 W) and rabbit skin (500 W). A short extraction time of 5 min may not be sufficient for collagen to completely hydrolyse to extract the gelatin from duck feet [68], and a longer extraction time of 60 min [69] may over-hydrolyse the protein structure. Since collagen crosslinks are unstable at high thermal levels, a low yield of gelatin is generally obtained because there is a loss of the three-dimensional structure of the protein.…”