Study On Preparation Of Lycopene Microcapsules

Tomatoes are one of the most widely produced vegetables in the world. China is the world’s third largest tomato-producing country,next to the United Stated and Italy.More than one million tonnes of tomatoes are produced annually in China,mostly from Xinjiang province.Lycopene is known to the scientific and medical world for its ability to cardiovascular decrease the risk of disease as well as reducing the risk of some cancers. This fact has made lycopene popular in the healthy food markets in many countries.The way used to extract lycopene from tomatoes is efficient,but the high degree of unsaturation in the structure renders lycopene extremely sensitive to light,oxygen and humidity.Therefore,the nature lycopene must be protected in some forms from all kinds of damage before industrial application.Compared with the conventional methods,ultrasonic -emulsion solvent evaporation method can made the raw materials and emulsion much fine and homogeneous which was helpful to produce nanometer-sized microcapsules and it also associated with low temperature, speediness,high efficiency and environmental protection.In this article, ultrasonic-emulsion solvent evaporation method was studied to obtain the formations of lycopene microcapsules with two kinds of content.All the technological parameters impacted on encapsulation efficiency, lycopene-microcapsules’ stability and absorption of microcapsules in rat intestine were studied.The main results and conclusions were listed as followers:1.The lycopene-microcapsules were obtained by ultrasonic emulsication.Several factors affecting encapsulation efficiency of lycopene micro-encapsulation were investigated in details and optimized by Plackett-Burman and central composite design.Response surface methodology was applied to optimize the most obvious impact factors,the two results were as followers:Formation of lycopene injection:0.55g glycerin monostearate was fully dissolved in 5.00 mL ethyl acetate and then added 0.02 g lycopene to form an organic phase,101.0 mL distilled water which dissolved 0.60 g F68 as the aqueous phase.The organic phase was pulled into the aqueous phase with agitation in 60℃water bath for 5 min.The mixture was then ultrasonic homogenized in an ultrasonic comminution of cell equipment under 380 W homogenization power for 20 min to form a homogenous emulsion.The resulting emulsion was rotary evaporated while equipped with a pear-shaped flask with dimensions of 250 mL in 50℃water bath for 10 min under a pressure of 200 hPa.The optimized formation reached an encapsulation efficiency of 61.59%.Formation of lycopene oral dosage:0.04 g glycerin monostearate was fully dissolved in 5.00 mL ethyl acetate and then added 0.02 g lycopene to form an organic phase,100.0 mL distilled water which dissolved 0.04 g RH-40 as the aqueous phase.The organic phase was pulled into the aqueous phase with agitation in 60℃water bath for 5.5 min.Then the mixture was ultrasonic homogenized in an ultrasonic comminution of cell equipment under 836 W homogenization power for 20 min to form a homogenous emulsion.The resulting emulsion was rotary evaporated while equipped with a pear-shaped flask with dimensions of 250 mL in 50℃water bath for 10 min under a pressure of 200 hPa.The optimized formation reached an encapsulation efficiency of 56.32%.2.Vacuum freeze-drying was used to prepare the lycopene nano-microcapsule powder to convenient conservation,transportation and application.To prepare lycopene nano-microcapsule powder with high stability,several different cryoprotectors were studied through comparing with their physicochemical characteristics.The protective effects were evaluated by measuring the particle diameter,appearance and dissolution, as well as the stability before and after freeze-drying process.The lycopenen powder contained 5%mannitol was round or ellipse,smooth with even distributions and easy to be dissolved with 0.80±0.30μm particle diameter.When stored at 4℃for 2 month,the content of lycopene nano-microcapsules powder without cryoprotectors and with 5%mannitol were 7.14%and 88.10%separately.Infra-red spectrum and differential scanning calorimetry showed that lycopene nano-microcapsules were well encapsulated in the wall material.Lycopene nano-microcapsules acquired substantially increased ability to withstand degration through exposure to light,oxygen and humidity when compared to the nature lycopene.3.After microencapsulation,the solubilization capacity of lycopene was improved and bioavailability was increased.To evaluate the absorption of lycopene microencapsule in rat intestine,in-situ recirculation model was used and the concentration of lycopene in the perfusate was determined by spectrophotometric method.The diameter of lycopene microcapsule was 1.333μm and the absorption rate constants at the entire intestine was（0.39±0.08） h^-1,while the absorption rate of lycopene micelle was（0.28±0.03 ） h^-1.The absorption was a first-order process with the passive diffusion mechanism.The absorption appeared a concentration adependence.Compared with the male,the female rats had a higher absorption rate constants and accumulative absorption percentage.