薯蓣皂素在食用油脂中有机凝胶性能和氧化特性研究

研究了薯蓣皂素在油相中的有机凝胶性能及其氧化特性。质构分析表明薯蓣皂素在浓度低至3%时即可在油相中形成有机凝胶,硬度相当于三硬脂酸甘油酯的1.6倍左右。偏光显微镜观察出油相中的薯蓣皂素可自组装成簇状晶体网络结构。红外光谱图显示,样品在未完全融化时,羟基伸缩振动特征峰从3452.44 cm~(-1)红移到3 395.23 cm~(-1),谱带变宽,显示形成分子间氢键;完全融化时,羟基伸缩振动特征峰发生蓝移,并在1 720.99 cm~(-1)波数处出现新的官能团酮基,显示氢键效应减弱。快速液相色谱串联四极杆飞行时间质谱法证明了其融化样品中有环己烯酮和环己酮结构的氧化产物出现,影响到原薯蓣皂素分子间形成的氢键。随着融化时间的延长,质构分析表明薯蓣皂素油相样品的硬度下降。

Organgel properties and oxidation characteristics of diogenes in edible oil

The organgel properties and oxidation characteristics of diogenes in the oil were investigated. Texture analysis (TA) showed that diogenes can form gels at concentrations as low as 3% wt/wt, the hardness provided by diogenes was equivalently 1.6 times as that of tristearin. The diogenes in the oil phase presented a new kind of self-assembly crystal structure with turfed shape, which was observed by polarized light microscopy. The hydroxyl bond was broaden and red-shifted from 3452.44cm-1 to 3395.23cm-1 when the diogenes was not completely melt, which indicated the formation of intermolecular hydrogen bonds. While the diogenes was completely melt, the stretching vibration of hydroxyl groups resulted in blue-shifted, and keto group appeared at 1720.99 cm-1. Rapid liquid chromatography quadrupole time of flight mass spectrometry (LC-QTOF-MS) verified that oxidation generated cyclohexenone and cyclohexanone structure, which affected intermolecular hydrogen bonds. With the extension of the melting time, texture analysis showed that the hardness of diosgenin in the oil phase was reduced.