Study On The Preparation Of Curcumin Xerogel Beads

Curcumin,as a polyphenolic substance,has many functions and is often added to functional foods.It has been reported that curcumin can inhibit the growth of colon tumor stem cells and can also be used for the treatment of colon inflammation.Oral colon-targeting drugs have the advantage of being patient friendly and low cost compared with injection and rectal administration.However,the low solubility of curcumin in water and the poor absorption of curcumin after oral administration limit its application.Curcumin was encapsulated with hydrogel to improve its stability and release in digestive tract.However,the high water content of hydrogels makes it difficult to store and expensive to transport.In order to prolong the storage time and reduce the transportation cost,the hydrogel needs to be dried to reduce the moisture content.The physicochemical properties of pectin-sodium alginate hydrogel beads prepared by different drying methods were studied.The suitable drying method of pectin-sodium alginate hydrogel bead was obtained.Then hydroxypropyl-?-cyclodextrinwas used to encapsulate curcumin to improve the solubility.Then,hydrogel beads containing the inclusion complex were prepared by encapsulating curcumin with hydroxypropyl-?-cyclodextrin to delay the release of curcumin in vivo.Then the effect of different drying methods on the properties of curcumin inclusion hydrogel beads was studied,and the suitable drying method of pectin-sodium alginate hydrogel beads containing HP-?-CD-Cin was obtained.The main research results of this paper are as follows:1.The hydrogel beads of pectin and sodium alginate were dried by natural drying,far-infrared drying,vacuum freeze drying,hot air drying and fluidized bed drying.The energy consumption in drying process and the physicochemical properties of hydrogel beads were measured.The results show that the sample sizes from small to large are hot air drying sample(153.47±11.63 ?m),fluidized bed drying sample(149.83±1.18?m),far infrared drying sample(229.91±12.08 ?m),vacuum freeze drying sample(249.98±6.82 ?m),natural drying sample(252.27±7.26 ?m).The sample total color difference from small to large is fluidized bed drying(14.09),hot air drying(30.35),far infrared drying(30.55),vacuum freeze drying(30.60),natural drying(43.41).The order of energy consumption from small to large is far infrared hot air drying(16.00 k W·h/kg),hot air drying(19.50 k W·h/kg),fluidized bed drying(51.43 k W·h/kg),vacuum freeze drying(70.40 k W·h/kg).The sample swelling degree from small to large is hot air drying,far infrared drying,natural drying,fluidized bed drying,vacuum freeze-drying,and the fluidized bed drying remains undissolved for a period of time.The water distribution of hydrogel beads during the drying process showed that the water migration mode was different in different drying processes.Therefore,it can be concluded that the properties of pectin-sodium alginate hydrogel beads prepared by fluidized bed drying are better.2.HP-?-CD-Cin was prepared by solvent evaporation,grinding and p H method.The results showed that compared with the grinding method and p H method,the HP-?-CD-Cin prepared by solvent evaporation method had higher encapsulation efficiency(45.34 %)and better solubility(78.75 ?g/m L).The inclusion complex of curcumin prepared by solvent evaporation method was successfully incorporated into the complex by Fourier transform infrared spectroscopy and X-ray diffraction.The encapsulation rate and loading rate of curcumin in the hydrogel beads were studied by preparing hydrogel beads loaded with different amounts of inclusion complex.It was concluded that the encapsulation rate and loading rate of curcumin in the hydrogel beads were better when 3.0 mg/m L curcumin inclusion complex was added.By comparing the stability of the hydrogel beads containing the inclusion complex and the inclusion complex,the hydrogel beads containing the inclusion complex had better stability than the inclusion complex in the protection of the relative content of curcumin.3.The effects of hot air drying,vacuum freeze drying and fluidized bed drying on the physicochemical properties of hydrogel beads containing curcumin inclusion complex pectin and sodium alginate were studied.The sample size of hot air drying is the smallest(128.84±2.16 ?m),the microstructure surface sag is the largest,the color difference is the largest(61.41),the swelling degree is the smallest,the volume of curcumin encapsulation is the smallest(76.28 ?g/mg),the curcumin release is the slowest.Vacuum freeze drying has the largest sample size(257.10 ?m),followed by color difference(23.28),the drying process has the largest energy consumption(70.40 k W·h/kg),the largest swelling degree,the largest amount of curcumin encapsulation(152.35 ?g/mg),and the fastest curcumin release.Fluidized bed drying sample has the minimum color difference(17.65),the minimum specific surface(1.061m2/g),the fastest release of curcumin.In vitro simulated digestion experiments showed that curcumin in the colon of fluidized bed drying samples was the most reserved,while hot air drying was the least.In conclusion,fluidized bed drying has little effect on the physical and chemical properties of hydrogel beads,and has a better sustained-release effect,fluidized bed dried hydrogel beads better release curcumin in the colon.This study concluded that the fluidized bed drying method is suitable for the drying of pectin-sodium alginate hydrogel beads containing curcumin inclusion complex,which solves the problem that the wet base of hydrogel beads is difficult to transport and preserve,and provides a feasible way for the drying of hydrogel beads.