碱性微晶纤维素在茶籽油脱酸工艺中的应用

Application of alkaline microcrystalline cellulose in deacidification of tea seed oil

为改进茶籽油脱酸工艺,以微晶纤维素(microcrystalline cellulose,MCC)和氢氧化钠(Na OH)为原料,采用固相合成的方法制成一种碱性微晶纤维素(alkaline microcrystalline cellulose,AMC),并通过傅里叶红外光谱分析、X-射线衍射分析、热重分析和扫描电子显微镜对其进行了结构表征,继而考察AMC对低温压榨茶籽油中游离脂肪酸(free fatty acid,FFA)的吸附效果,通过单因素和正交实验得出了最优的脱酸工艺条件。结果表明,AMC的制成过程中,MCC与Na OH发生了络合,分子间原有的结构被破坏,结晶度降低,氢键作用力减弱,热稳定性下降,表面疏松程度和孔隙增加,吸附能力增强。在脱酸时间为2h,AMC添加量为2.5%,脱酸温度为45℃的条件下,AMC的吸附脱酸效果最好,此条件下茶籽油的酸价降低了3.15mg KOH/g。

For better deacidification of tea seed oil,alkaline microcrystalline cellulose（ AMC） was modified by solid- phase synthesis with microcrystalline cellulose（ MCC） and sodium hydroxide（ Na OH）. AMC and MCC were analyzed by Fourier infrared spectrum,X- ray diffraction,thermal gravimetric analyzer and scanning electron microscope. The effect of AMC on removal of free fatty acids（ FFA） from cold- pressed tea seed oil was also studied. Results showed that compared with MCC,crystallinity,hydrogen bonding force and thermal stability of AMC were decreased,while its surface loose degree and porosity increased,and adsorption capacity increased. The optimal deacidification conditions were determined through single- factor and orthogonal experiments. The optimum deacidification time was 2 hours at 45℃,and AMC amount was 2. 5%. Under the above conditions,acid value of tea seed oil could be reduced by 3. 15 mg KOH / g.