以提取的玉米秸秆纤维素为原料制备羧甲基纤维素,在其中添加甘油和不同浓度的AgNO3后制得改性复合膜.通过扫描电子显微镜(SEM)、X射线衍射(XRD)、X射线光电子能谱(XPS)、热重分析(TGA)、傅里叶红外光谱(FT-IR)对改性复合膜进行结构和形貌表征,结果表明:改性复合膜质地均匀,部分Ag+以单质银的形式与膜中的成分相互作用,膜热稳定性良好,满足保鲜材料要求.改性复合膜对大肠杆菌(E.coli)及白色葡萄球菌(S.albus)的抑制情况进一步证明了其中存在单质Ag粒子,对S.albus的抑制能力更强.用改性复合膜包裹蓝莓,存储10 d后的失重率低于7％、颜色几乎没有变化;可溶性固形物损失小于3％、可滴定酸下降不明显,当加入1 mL 0.01 mol/LAgNO3时,改性复合膜的保鲜性能相对较好.
Preparation of Modified Carboxymethyl Cellulose Composite Membrane and its Preservation Properties for Blueberry
Carboxymethyl cellulose was prepared from extracted corn stalk cellulose,and modified composite membrane was prepared by adding glycerol and different concentrations of AgNO3 into it.The structure and morpholo-gy of the modified composite film were characterized by scanning electron microscope (SEM ),X-ray diffraction (XRD),X-ray photoelectron spectroscopy (XPS),thermogravimetric analysis (TGA)and Fourier infrared spec-troscopy (FT-IR).The results indicated that the modified composite film had a uniform texture,some Ag+interac-ted with the components in the film in the form of elemental silver,and the film had good thermal stability,meeting the requirements of fresh-keeping materials.The inhibition of the modified composite membrane on E.coli and S.albus further proved that there were elemental Ag particles in it,and the inhibition ability on S.albus was stronger.When blueberries were wrapped with modified composite film,the weight loss rate was less than 7％ and the color al-most did not change after 10 days of storage.The loss of soluble solids was less than 3％,and the decrease of titrable acid was not obvious.When 1 mL of 0.01 mol/L-1 AgNO3 was added,the preservation performance of the modified composite membrane was relatively good.
万方数据
维普
