Reasearch On Preparation And Properities Of Curcumin-Loaded Organogel

In recent years, people pay more attention to the security and nutrition of food, and the lack of micronutrient intake is one of the main problem in Chinese residents’ dietary structure. Actually, some of tranditional food processing exist food security risk because of the health hazards materials produced during processing. Plastic fat is one of common raw materials used in food industry which could produce by hydrogenation process, but this processing would bring trans fatty acids and saturated fatty acids that are extremely harmful to human health. Curcumin is kind of plant polyphenols with variety biological activity, such as antioxidant, anti-tumor activity, but poor water solubility and low bioavailability greatly limits its application. Structuring liquid oils has become an active areaof research in the past decade, mainly due to its potential in reduceing saturated fat and trans fats intake. Meanwhile, three-dimensional network within organogel provide a favorable condition to load curcumin. Therefore, utilizing organogel to carry curcumin could produce a kind of food raw material combine security and nutrition, which would preformance great application potential in food industry.Firstly, considering the loading capacity and encapsulation efficiency of organogel, the key factors affect the solubility of curcumin and three-dimensional network structure of organogel were studied. The results showed that the solubility of curcumin closely related to loading methods, melting temperature and melting time. The best loading effect can be obtained by dissolving structurant firstly and then dissolving curcumin. Comparing to melting temperature, melting time is more important to the solubility of curcumin, 25 min is the best melting temperature. With the same melting time, increasing melting temperature could increase curcumin loading capacity of organogel, The melting point of ethylcellulose is 170℃, the biggest loading capacity(LC) and encapsulation efficiency(EE) were achieved in this system, 4.81±0.17mg/g and 96.19±3.48%, respectively. Moreover, the loading capacity closely related to three-dimensional network structure of organogel, storage temperature, structurant type and proportion were the key factors. Sitosterol and lecithin(S+L) organogel obtained the tightest structure, gained higher LC and EE, 3.14±0.10mg/g and 62.78±2.01%, respectively. Increasing structurant proportion could also increase organogel’s loading capacity. Otherwise, the higher storage temperature the tighter structure that organogel could obtain, the LC and EE of curcumin could also increased at last, for example, LC and EE of organogel storaged in 25 and 5℃ were 3.14±0.10mg/g and 62.78±2.01%、2.54±0.19mg/g and 50.81±3.70%. Otherwise, comparing to pure corn oil, organogel could guarantee the stability of curcumin during long storage.Secondly, based on the key factors affect curcumin’s loading amount, combining the loading capacity and encapsulation efficiency of organogel, the macroscopic properties and microstructure of different organogel(with different structurant and proportion) were measured by modern instrumental analysis(rheometer,pNMR,PLM �'� XRD). The structure changes of pure organogel and curcumin+organogel system were also studied. The results showed different structurant form different structure organogel, sitosterol and lecithin(S+L) and ceramide(CO) formed a similar crystal unit, but S+L organogel obtained tighter structure; differ from S+Land CO, the crystal unit of EC was graininess granulate and the three-dimensional network is loose, gel strength was between S+L and CO. Moreover, increasing structurant proportion could increasing the mount of crystal unit and internal cross-link which lead to the increase of organoge’ strength, for instance, the strength of S+L system were: 12%>10%>8%. Otherwise, among all the samples, curcumin did not change organogel’ crystal and three-dimensional network, that is to say, curcumin did not participate the formation of organogl’ structure. From the analysis of results, the loading mechanism of curcumin in organogel could be explained as: curcumin was dissolving in oil phase at first, and then packed by three-dimensional network structure which provided by structurant.Thirdly, based on the curcumin+organogel, pure organogel and corn oil+curcumin system, Schaal oven storage test was used to study its oxidation stability; in vitro experiments were also conducted to investigated the extent of lipolysis and curcumin bioavailability. The results showed, during primary oxidation, the PV of curcumin+organogel showed the lowest rising rate, the PV still <5mmol/kg after 9 days, indicating that curcumin could play its antioxidant activity with the protection of organogel’ network. In addition, during secondary oxidation, the AV of three systems were: corn oil+curcumin > pure organogel > curcumin+organogel, indicating that the organogel network structure could limits the migration of lipid radicals, and then slow down the secondary oxidation of system. Schaal oven storage test showed curcumin-organogel performance good oxidation stability in long time storage. Meanwhile, in vitro experiments, the formation of organogel network structure did not affect the occurrence of lipolysis reaction; and compare to pure corn oil, the curcumin bioavailability has increased a lot, the highest bioavailability could reach 67.66±5.91%.Through the study of the key factors which affect organogel’s loading capacity and encapsulation efficiency and organogel’s properties, curcumin loading mechanism was explained in detail. The oxidation stability and curcumin release experiment measured the functionality of curcumin-organogel, indicating its potential application in food industry. In a word, this study provides method reference and theoretical support to curcumin-organogel’ application in practice.