Thermal properties and adhesion strength of modified soybean storage proteins
Thermal properties and adhesion strength of modified soybean storage proteins
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DOI：
10.1007/s11746-004-0912-9
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发表时间：
2004-04
期刊：
影响因子：
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通讯作者：
Xiaoqun Mo;X. Sun;Donghai Wang
中科院分区：
文献类型：
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作者：
Xiaoqun Mo;X. Sun;Donghai Wang
大豆蛋白在粘合剂和树脂应用中显示出巨大的潜力。本研究表征了化学改性后大豆蛋白主要成分伴大豆球蛋白 (7S) 和大豆球蛋白 (11S) 的热性能和粘合性能。这些球蛋白是从脱脂大豆粉中提取的，然后用氢氧化钠、十二烷基硫酸钠 (SDS) 或尿素进行修饰。使用 DSC 评估改性 7S、11S 以及不同比例的 7S 和 11S 混合物与樱桃木单板胶合板的胶合强度以及热变性。所有用氢氧化钠修饰的蛋白质的粘合强度和耐水性均得到显着提高。含有较多 7S 球蛋白的 SDS 和脲修饰蛋白的粘合强度和耐水性得到改善。对于含有大量 11S 球蛋白的蛋白质，观察到相反的行为。 DSC结果表明，用氢氧化钠或尿素修饰的蛋白质的变性温度（Td）降低，而用SDS修饰的蛋白质的Td值与未修饰的蛋白质相似。这些结果表明，在研究的浓度下，氢氧化钠或尿素可以比 SDS 更有效地使大豆蛋白变性，从而导致蛋白质热稳定性较低。 11S 比例高的大豆蛋白具有更有序的结构，DSC 测量中观察到的蛋白质变性的高焓值证明了这一点。
Soy proteins have shown great potential for adhesive and resin applications. This investigation characterized the thermal and adhesive properties of the major soy protein components conglycinin (7S) and glycinin (11S) after chemical modification. These globulins were extracted from defatted soy flour, then modified with either sodium hydroxide, sodium dodecyl sulfate (SDS), or urea. Modified 7S, 11S, and mixtures of 7S and 11S at varying ratios were evaluated for gluing strength with cherry veneer plywood and for thermal denaturation using DSC. Adhesive strength and water resistance were significantly improved for all proteins modified with sodium hydroxide. Gluing strength and water resistance were improved for SDS‐ and ureamodified proteins containing greater portions of 7S globulins. The opposite behavior was observed for proteins containing large amounts of 11S globulins. DSC results showed that the temperatures of denaturation (Td) decreased for the proteins modified with sodium hydroxide or urea, whereas theTdvalues of proteins modified with SDS were similar to the unmodified proteins. These results suggested that, at the concentrations studied, sodium hydroxide or urea could denature soybean protein more effectively than SDS, resulting in lower protein thermal stability. Soybean proteins with high ratios of 11S had more ordered structures, as evidenced by the high enthalpy values of protein denaturation observed in DSC measurements.