大豆分離蛋白/羧甲基纖維素共混包裝薄膜的制備與性能研究


內(nèi)容摘要：以羧甲基纖維素(CMC)和大豆蛋白(SPI)為原料，通過加入甘油采用共混的方法制備薄膜。羧甲基纖維素對共混薄膜的結(jié)構(gòu)、熱穩(wěn)定性和機(jī)械強(qiáng)度都有一定的系統(tǒng)改進(jìn)。通過紅外光譜分析(FTIR)，可知：CMC和SPI發(fā)生美拉德反應(yīng)，CMC中的-OH基團(tuán)和SPI中的氨基團(tuán)在升溫成鍵過程中被消耗了，生成C=N鍵；通過XRD測試，可驗(yàn)證美拉德反應(yīng)，隨著CMC和甘油的增加會對SPI的結(jié)晶結(jié)構(gòu)和結(jié)晶度構(gòu)成破壞；通過機(jī)械性能測試，可知：無甘油時，CMC/SPI共混薄膜隨CMC添加量的增加，薄膜的屈服應(yīng)力和斷裂應(yīng)力相應(yīng)增加，這是由于分子間交聯(lián)的結(jié)果，且加入甘油后共混膜會變得更加柔軟，機(jī)械力學(xué)性能增強(qiáng)；通過熱失重(TGA)，可知：混合膜的熱穩(wěn)定性均比純SPI粉末要高且隨著CMC添加比例的升高，混合膜的熱穩(wěn)定性提高。結(jié)果證明，大豆蛋白共混羧甲基纖維素可以改善和提高膜的結(jié)構(gòu)和性能。

關(guān)鍵詞：羧甲基纖維素；大豆蛋白；美拉德反應(yīng)；共混


 


 


 


 


 


 


 


 


 


 


 


 


Preparation and characterization of soy protein isolate / carboxymethyl cellulose blend films

Abstract: Films based on carboxymethyl cellulose (CMC) and soy protein isolate (SPI) with compatibilized by glycerol were respectively prepared by a solution-casting method. The effects of CMC contents on the blend structure, thermal stability, as well as mechanical properties, were systematically investigated. FTIR results showed that Maillard reactions occurred between CMC and SPI, these result show that the –OH group in CMC and amino groups in SPI were consumed during the blending process at elevated temperature. Moreover, a new C=N was inducted. XRD curves indicated Maillard reactions had broken the crystalline of SPI, with the increasing of CMC and glycerol contents in blend films. For CMC/SPI samples without glycerol, the values of σy and σb increase with increasing CMC content, respectively, that because mechanical properties of the SPI blends depend on the crosslinking methodology and the blend becomes softer due to plasticization by glycerol, the mechanical prosperities had been improved. TGA curves indicated blend reaction could improve stability of SPI. With the increasing of CMC contents in blend films, the stability had been improved. These results showed that the structure and properties of SPI films were modified and improved by blending with CMC.

Keywords: Carboxymethyl cellulose; Soy protein isolate; Maillard reactions; Blend