Tourism and Cuisine College, Yangzhou University, Yangzhou 225127, China.
Tourism and Cuisine College, Yangzhou University, Yangzhou 225127, China.
Ultrason Sonochem. 2023 Aug;98:106478. doi: 10.1016/j.ultsonch.2023.106478. Epub 2023 Jun 9.
The β-conglycinin (7S) was pre-treated with high-intensity ultrasonic (HIU) and subsequently formed into composite edible films with the transglutaminase (TGase) method. Effects of HIU pretreatment time (0, 5, 10, 15, and 20 min) on the conformation of 7S and structural and application properties of 7S-TGase films were evaluated. The analysis of 7S conformation results revealed that HIU pretreatment for 0-10 min significantly dissociated the 7S, exposed internal hydrophobic groups of protein, increased its intermolecular hydrogen bonds, and altered the protein secondary and tertiary structure. The structural properties of films were evaluated by SEM, XRD, and ATR-FTIR. SEM showed that HIU reduced film wrinkles and cracks and improved unevenness. XRD and ATR-FTIR indicated that the film obtained an enlarged crystallinity, and the amide I and amide II regions of films were peak-shifted which is usually associated with the formation of covalent bonds. Notably, analysis of intermolecular force showed that HIU facilitated the formation of hydrogen bonds, hydrophobic interactions, and ε-(γ-glutamyl) lysine bonds in 7S-TGase films. The above structural changes in 7S and films were beneficial for the application properties of films. Results indicated that 10 min HIU pretreatment effectively improved the mechanical properties and water resistance, reduced water vapor permeability and oxygen permeability, and decreased the opacity of 7S-TGase films. However, the color of the film was not affected by the HIU, with an overall bright and yellowish color.
β-伴球蛋白（7S）经高强度超声（HIU）预处理，随后用转谷氨酰胺酶（TGase）法制成复合可食用膜。评价 HIU 预处理时间（0、5、10、15 和 20 分钟）对 7S 构象及 7S-TGase 膜结构和应用性能的影响。7S 构象分析结果表明，HIU 预处理 0-10 分钟可显著解离 7S，暴露出蛋白质内部疏水基团，增加其分子间氢键，并改变蛋白质二级和三级结构。通过 SEM、XRD 和 ATR-FTIR 对膜的结构性能进行评价。SEM 表明 HIU 减少了膜的皱纹和裂纹，提高了膜的均匀性。XRD 和 ATR-FTIR 表明，所获得的膜结晶度增大，且酰胺 I 和酰胺 II 区域的峰发生偏移，这通常与共价键的形成有关。值得注意的是，分子间作用力分析表明，HIU 促进了氢键、疏水相互作用和 ε-（γ-谷氨酰基）赖氨酸键在 7S-TGase 膜中的形成。7S 和膜的上述结构变化有利于膜的应用性能。结果表明，10 分钟 HIU 预处理可有效提高 7S-TGase 膜的力学性能和耐水性，降低水蒸气透过率和氧气透过率，降低膜的不透明度。然而，HIU 对膜的颜色没有影响，整体呈明亮的浅黄色。
