The Preparation And Characteristics Of Oryzanol/Sitosterol And Monoglyceride Oleogel

At present,the food grade gelators with great potential were oryzanol/sitosterol and monoglyceride,however,there were some defects for this two kinds of small molecules oleogels,among which oryzanol/sitosterol oleogel was expensive,and the hardness was too high to smear even in the critical gel concentration.Other studies show that sitosterol and water can form a sterol compound,which will disturb the formation of intermolecular hydrogen bonds between oryzanol and sitosterol,as the result the hollow tubes structure which depends on the intermolecular hydrogen bond would be affected.While the hardness and oil binding ability of oleogel formed by monoglyceride was weak.According to the characteristics of these two kinds of oleogels,a feasible way was to combine the oryzanol/sitosterol and monoglyceride to form a composite oleogel,so that the quality would be improved.There were no reports on the study of two kinds of gelators which could be used to form oleogel alone.This paper studied the interaction between two gelators with different structured mechanism.At the same time,according to the nature of solid oil products on the market,a more perfect oleogel was developed as a substitute for solid oil.Oryzanol/sitosterol and monoglyceride were selected as gelators and structured the vegetable oil from the perspective of gelator molecular structure and nutrition.Preparation conditions of sunflower oil oleogels was optimised by Response Surface based on the single factor experiment,and a oleogel with low oil losing rate was obtained.Besides,the properties between liquid oil and oleogel were compared,as well as the properties of oleogels prepared by single and composite gelator.The results show that basic physical and chemical indexes of the composite-gelator oleogel can meet the national standard,and the linear viscoelastic region is wider than that of the single-gelator oleogels.After the optimum process conditions was obtained,the effect of ratio among gelators which was the main factors on the properties of oleogel was analyzed,different ratio among gelators wonld affect the intermolecular interaction of gelators,thus,different assembly structures are obtained and ultimately lead to the differences in the performance of macro view.The results show that a synergistic effect may be occurred between monoglyceride and sitosterol,as the result oleogel was prepared below the critical gelation concentration of each gelators,the viscoelastic modulus of oleogels decreased with the increase of monoglyceride proportion,which improved movement capacity of gelators in oil,and increased a highly assembled tendency of gelators along single axis,and finally led to the changes of assembled aggregation structure and superamolecular network topology,and then enhanced the interaction between the building elements in the network and increased the storage stability of oleogels.Modern analytical techniques were used to thoroughly study the gelation mechanism,crystal structure,condensed structure and the finally changes of macroscopic properties.With the decrease of monoglyceride proportion,it would be increasingly difficult for the system to achieve the supercooled state,and in general the time for oleogel formation would also be lagged,this lagged phenomenon is more significant in oleogel with oryzanol/sitosterol and monoglyceride ratio was 6:4.At the same time,the solubility of oryzanol/sitosterol in vegetable oil could be increased by monoglyceride,as the result the energy barrier of crystallographic mismatch of sitosterol molecules would be reduced,which would promote the crystal growth along the one-dimensional direction,and finally caused the change of network topology structure of gelators.Monoglyceride would increase the crystallization in oleogel,and accelerate the formation of oleogel network structure,those changes on arrangement,assembly and network topology structure leads to the improvement of macroscopic properties(such as texture,elasticity,thermoplastic).In addition,the potential application of oleogel used as base oil for preparating margarine was investigated.The study show that the gelation ability of gelators was influenced by water content in system with aqueous,the more the water content,the greater the hardness of oleogel-basd margarine,many characteristics of oleogel-basd margarine with 7% water content was similar to that of commercially available margarine,but there were some difference on crystallization characteristics between saturated fat in commercially available margarine and oleogel in oleogel-basd margarine.This paper built a mechanism model based on the change of stacked geometric structure of gelator induced gelation,and put forward a self-assembly growth model for oleogels,and moreover,mastered the rules of change in different oleogel systems and in multi-scale structure changes of oleogels during storage as well as its consequence on the physical properties,which could provide valuable basic data and theory for more reasonable design of oleogelators and guiding the processing and application of oleogels.