香榧油-薯蓣皂素油凝胶的制备及其结构和消化特性研究

Investigation of the preparation,structure,and digestive characteristics of Torreya grandis oil-diosgenin oleogels

以香榧油(Torreya grandis oil, TGO)为油相、薯蓣皂素(Diosgenin, DSG)为凝胶剂制备TGO-DSG油凝胶(TDOG油凝胶),研究其微观结构、流变特性、质构特性、晶体结构等,以及其凝胶形成原理及凝胶化对其消化特性的影响规律。结果表明:TDOG油凝胶是由小而密和大而松散的两种球状DSG结晶通过纤维交联的三维网络构建而成。TDOG油凝胶的储能模量(G′)大于损耗模量(G″),呈现剪切稀化特征,相转变温度约为86.8℃。当消化时间为120 min时,TDOG油凝胶的消化率为40.7%,显著低于TGO(50.9%),即凝胶化能降低TDOG中TGO的消化率;另外,TDOG油凝胶消化上清液中的饱和脂肪酸含量高于不饱和脂肪酸,即凝胶化会增加不饱和脂肪酸的消化难度,且不饱和度越高其消化难度越大。因此,TDOG油凝胶可作为固体脂肪的替代品,应用于健康功能食品的开发。

TGO-DSG oleogel(TDOG oleogel)was prepared with Torreya grandis oil(TGO)as the oil phase and Diosgenin(DSG)as the gelator,and its microstructure,rheological properties,texture properties,and crystal structure were investigated.The gelation mechanism of TDOG oleogel and the effect of gelation on the in-vitro digestion characteristics were also discussed.The results presented that TDOG oleogel was composed of small and dense or large and loose flocs DSG crystals,which were constructed through the fiber cross-linked three-dimensional network;the storage modulus(G′)of TDOG oleogel was larger than the loss modulus(G″),and TDOG oleogel presented shear thinning characteristics,and the phase transition temperature was about 86.8℃.When the digestion time was 120 min,the digestibility of TDOG oleogel was 40.7%,significantly lower than that of TGO(50.9%),indicating that gelation could reduce the digestibility of TGO in TDOG.In addition,the content of saturated fatty acids in the 120 min digestible supernatant of TDOG oleogel was higher than unsaturated fatty acids,indicating that oil gelation would increase the difficulty of digestion of unsaturated fatty acids,and the higher the unsaturation,the greater the digestion difficulty was.Therefore,TDOG oleogels could be used as an alternative to solid fats for the development of healthy functional foods.