Preparation And Characterization Of Medium-chain Triglycerides Microcapsules

Medium-chain triglycerides is a lipid modified from natural oil, with less accumulation of fat increases and potential role in regulating blood Cholesterol, therefore, as a widely used functional oil in food, medicine and chemical industry. But the human intake of more than a certain amount of medium-chain triglycerides may cause abdominal pain and diarrhea, making the use of medium chain triglycerides limited. Preparation of MCT-load microcapsules can change the MCT from a liquid to a solid, improve its mobility and mixing, ease of processing and preservation, and controlled release microcapsules can make MCT release and absorped slowly, thus the avoidance of abdominal pain and diarrhea.Using the screening test of wall material and emulsifier to selected suitable wall material and emulsifier for preparation of medium-chain triglycerides microcapsule. Base on single factor test, a series of Box-Benhnken design experiments was used to obtain a mathematical regression model for entrapment efficiency as response of three variables. Three independent variables were used:ratio of core material to wall material, emulsifier concentration, emulsion concentration. Response surfaces were drawn for analyzing the interactive effects of the above variables on entrapment efficiency. Results indicated the optimum preparation conditions of MCT-load microcapsules were as follows:wall material were dextrin and casein, emulsifier were monoglycerides and Lactylate stearic, temperature of emulsifying was 60℃, ratio of core material to wall material was 3.56:6.44, emulsifier concentration was 3.59%, and emulsion concentration was 27.6%, with entrapment efficiency of 96.33%.By investigating the MCT-load microcapsules' quality, the results showed that: moisture content was low (2.5%), density was 0.36g/cm, the power was exquisite and uniform, the color was ivory, the smell was pure. Its physical and chemical indicators of quality was in line with the standard of microcapsules. IR spectra results show that the encapsulated medium-chain triglyceride remained the original structure; scanning electron microscopy confirmed that the microcapsules have entrapment efficiency and microencapsulation can protect the core material; differential scanning calorimetry (DSC) and thermo gravimetric analysis showed that the thermal melting temperature of microcapsules was high, and the microcapsule was stable in the majority of processing. The heat intensity experiment showed that, the micro-capsule destruction rate increased with increasing temperature, indicating that the microcapsules should not be storaged at a high temperature.The presence of time test of MCT-load microcapsules in artificial gastric and intestinal fluid showed that microcapsules existed in the artificial gastric juice longer and existed in the artificial intestinal fluid shorter, it had a good sustained release and enteric. The performance of release of the microcapsules in artificial gastric was investigated, and the release curve fitting results showed that the release of MCT-load microcapsules in artificial gastric followed first-class reaction kinetics. In other words, the release rate was proportional to the mass of the remaining core, the greater the microcapsule particles, the thicker wall membrane, release rate was smaller.We fed mice with basal diet, diet containing MCT-load microcapsules and diet containing LCT (soybean oil)-load microcapsules, respectively. The results showed that body weight of MCT group was significantly lower than that of LCT group, total cholesterol and low density lipoprotein cholesterol is also lower than LCT group. Therefore, MCT-load microcapsules can replace the current LCT-load microcapsules in some of applications, to prevent obesity and reduce weight gain and body fat accumulation, thus protect the human health.