Salem Ali, Abdelhedi Ola, Sebii Haifa, Ben Taheur Fadia, Fakhfakh Nahed, Jridi Mourad, Zouari Nacim, Debeaufort Frederic
Laboratory of Functional Physiology and Valorization of Bio-resources (LR17ES27), Higher Institute of Biotechnology of Beja (ISBB), University of Jendouba, 9000, Beja, Tunisia.
Food Valuation and Safety Analysis Laboratory, Engineering National School of Sfax (ENIS), University of Sfax, Sfax, Tunisia.
Heliyon. 2023 Aug 29;9(9):e19620. doi: 10.1016/j.heliyon.2023.e19620. eCollection 2023 Sep.
Gelatin derived from marine by-products could be an interesting alternative to classic mammalian gelatin. The pretreatment and extraction conditions could influence the size of the resulting peptide chains and therefore their techno-functional properties. Thus, it is important to optimize the production process to get a gelatin for the appropriate applications. Skin pretreatment was done by microwaves or oven-drying and the extracted gelatin was dried by spray- or freeze-drying. Freeze-dried gelatin extracted from untreated skin (FGUS) had the highest gelatin yield (10.40%). Gelatin proximate composition showed that proteins were the major component (87.12-89.95%), while lipids showed the lowest contents (0.65-2.26%). Glycine showed the highest level (299-316/1000 residues) in the extracted gelatins. Proline and hydroxyproline residues of gelatins from untreated skin were significantly higher than those from pretreated skin-gelatin. FTIR spectra were characterized by peaks of the amide A (3430-3284 cm), B (3000-2931 cm), I (1636-1672 cm), II (1539-1586 cm) and III (1000-1107 cm). Spray-drying decreased the gelling properties of gelatins, since it reduced gelling and melting temperatures compared to freeze-drying. Skin pretreatment significantly reduced the gel strength of gelatin by about 50-100 g depending on the gelatin drying method. The FGUS showed better surface properties compared to other gelatins. The highest emulsion activity index (39.42 ± 1.02 m/g) and foaming expansion (172.33 ± 2.35%) were measured at 3% FGUS. Therefore, the promising properties of freeze-dried gelatin derived from untreated skin, gave it the opportunity to be successfully used as a techno-functional ingredient in many formulations.
源自海洋副产品的明胶可能是传统哺乳动物明胶的一个有趣替代品。预处理和提取条件会影响所得肽链的大小，进而影响其技术功能特性。因此，优化生产工艺以获得适用于相应应用的明胶非常重要。皮肤预处理通过微波或烘箱干燥进行，提取的明胶通过喷雾干燥或冷冻干燥。从未经处理的皮肤中提取的冷冻干燥明胶（FGUS）具有最高的明胶产率（10.40%）。明胶的近似成分表明蛋白质是主要成分（87.12 - 89.95%），而脂质含量最低（0.65 - 2.26%）。甘氨酸在提取的明胶中含量最高（299 - 316/1000个残基）。未经处理的皮肤明胶中的脯氨酸和羟脯氨酸残基显著高于经预处理的皮肤明胶中的残基。傅里叶变换红外光谱的特征峰为酰胺A（3430 - 3284厘米）、B（3000 - 2931厘米）、I（1636 - 1672厘米）、II（1539 - 1586厘米）和III（1000 - 1107厘米）。喷雾干燥降低了明胶的凝胶化特性，因为与冷冻干燥相比，它降低了凝胶化温度和熔化温度。根据明胶干燥方法的不同，皮肤预处理使明胶的凝胶强度显著降低约50 - 100克。与其他明胶相比，FGUS表现出更好的表面性质。在3%的FGUS浓度下测得最高的乳化活性指数（39.42±1.02米/克）和发泡膨胀率（172.33±2.35%）。因此，从未经处理的皮肤中提取的冷冻干燥明胶所具有的良好特性，使其有机会成功地用作许多配方中的技术功能成分。
