等离子体辅助处理对鹰嘴豆淀粉-姜黄素复合物结构和功能性质的影响

Effects of plasma assisted pretreatment on the structure and functional property of chickpea starch-curcumin complex

目的探究等离子体辅助处理对鹰嘴豆淀粉-姜黄素复合物结构及功能性质的影响。方法采用介质阻挡等离子体技术辅助制备了鹰嘴豆淀粉-姜黄素复合物,运用扫描电子显微镜、傅里叶红外光谱仪与X-射线衍射仪等仪器手段表征了复合物微观结构、淀粉双螺旋结构和晶体结构,采用体外模型研究了淀粉消化特性。结果随着等离子体改性时间的增加,淀粉与姜黄素的复合指数逐渐升高,在等离子体处理90 s(电压60.0 V、电流1.0 A)时二者的复合指数最高为28.69%±2.51%,远高于对照组(8.50%±0.78%)。红外光谱显示改性后的淀粉与姜黄素之间氢键作用力增强,且随着等离子体改性时间的延长,特定波数出峰比值R1022/995由0.98降低至0.88,表明改性淀粉与姜黄素复合后的淀粉双螺旋结构有序性逐渐增加;并且复合物的结晶度略有上升,预示着姜黄素的晶体结构在复合物中的占比增加。淀粉体外消化实验表明,与对照组相比,等离子体辅助制备的复合物中淀粉消化速率和程度明显降低,且随着姜黄素复合指数逐渐升高,一阶动力学拟合的消化速率k值由0.085大幅度下降至0.029,快消化淀粉含量下降,慢消化淀粉含量显著升高。结论介质阻挡放电等离子体辅助处理显著提高了鹰嘴豆淀粉与姜黄素的复合率,本研究拟为拓展等离子体改性技术在制备淀粉-多酚复合物中的应用提供理论基础。

Objective To investigate the effects of plasma assisted pretreatment on the structure and functional properties of chickpea starch-curcumin complex.Methods The dielectric barrier discharge plasma was applied to assist the preparation of starch-curcumin complex,and the microstructure,double helix structure and crystal structure of the compound were characterized by scanning electron microscopy,Fourier transform infrared spectrometer and X-ray diffractometer.The digestion characteristics of starch were studied in vitro.Results The complex index between starch and curcumin was increased gradually with the extension of plasma modification duration.The highest complex index(28.69%±2.51%)was obtained when treated with 90 s plasma(generation voltage 60.0 V and input current 1.0 A),much higher than that of control group(8.50%±0.78%).Infrared spectra showed that the hydrogen bond between modified starch and curcumin was enhanced,and the peak ratio of specific wave number R1022/995 decreased from 0.98 to 0.88 with the extension of plasma modification time,indicating that the double helix structure of modified starch and curcumin was gradually increased.The X-ray diffraction showed that the relative crystallinity was slightly increased,indicating the increasing proportion of the crystalline structure of curcumin within complex.In vitro starch digestibility showed that the digestion rate and extent of complex prepared with plasma treatment was obviously reduced,compared with the control group.With the increasing complex index,the first-order kinetics fitting parameter k value gradually reduced from 0.085 to 0.029,and the rapid digestible starch content decreased,slow digestible starch content was significantly increased.Conclusion Dielectric barrier discharge plasma assisted pretreatment significantly improves the complexation efficiency between chickpea starch and curcumin.The conclusion of this study can provide theoretical basis for broadening the application of plasma modification technology in the preparation of starch-polyphenol complex.