超临界CO_2流体处理玉米淀粉产物性质的研究

Study on the properties of corn starch treated by SCF CO_2

以玉米原淀粉作对照,考察了超临界CO2流体萃取处理对淀粉的粗脂肪含量、颗粒形貌、晶体结构和吸附性能的影响。实验结果表明,分别在8、13、18、23、28MPa5个压力和40℃温度的超临界条件下处理淀粉4h后,其脂肪含量显著下降,扫描电镜(SEM)观察淀粉的颗粒形貌无明显变化。X-衍射分析显示:在28MPa的压力下所处理的淀粉样品,其衍射角为19.82°的衍射峰明显削弱;处理后样品结晶度有所增加,且在18MPa压力时达到最大值30.06%。超临界CO2流体处理后,淀粉吸附性能较原淀粉提高,在18MPa时达到最大,每克淀粉吸附芦丁的量为0.38mg,接近原淀粉吸附量的3倍。

The native corn starch was subjected to supercritical fluid extraction in 40℃ for 4h, with the treating pressure set as 8,13,18,23 and 28MPa respectively.Compared with native corn starch,the corn starch treated with SCF CO2 was characterized by Soxhlet extraction, scanning electronic microscope and X-ray diffraction. The adsorptive volume of rutin was studied as well.The results showed that the yield of total fat of the starch reduced significantly.The granules appearance was similar,the crystallinity increased slightly and achieved the maximum of 30.06%.In the curve of X-ray diffraction of the sample which was obtained at 28MPa,the peak occurred at 19.82° weakened obviously.The adsorptive volume of rutin increased to 0.38mg per gram starch,which was nearly 3 times of the native＇ s.