Extraction And Separation Of Yellow Pigment Components From Gardenia Jasminoides

Gardenia yellow pigment is a kind of food pigment extracted from Gardenia jasminoides.Its main active ingredients are croctin and crocin,which are the same as the active ingredients of saffron.Gardenia jasminoides are abundant and cheap in China,so it is of great significance and economic value to use Gardenia jasminoides as raw materials for the extraction of croctin and crocin.Ionic liquid is known as the21st century green solvent,which has the advantages of not volatile,good thermal stability,etc.,and is widely used in extraction research.At present,there are few reports on the extraction of croctin and crocin by ionic liquid.In this paper,two aqueous phase system and microemulsion system were constructed based on ionic liquid.They can be used to extract crocin and croctin from Gardenia jasminoides,which provides a reference for the extraction of microemulsion and two aqueous phase.The main experimental contents and results are as follows:(1)A two-phase system of ionic liquid was used to extract croctin.The phase forming capacity of five Ionic liquids with K₃PO₄for constructing a two-aqueous phase system was evaluated.The results show that the longer the alkyl side chain of ionic liquid is,the easier it was to form two aqueous phases.the phase forming capacity is[N₄₄₄₄]Cl<[P₄₄₄₄]Cl<[N₄₄₄₄]Br<[P₄₄₄₄]Br<[P₄₄₄₈]Br.Under the condition of the same cationic group,the phase forming ability of Br^-is greater than that of Cl^-.The physicochemical properties of ionic liquid two-phase system(ILs:K₃PO₄:H₂O=25%:15%:60%)were determined,The p H of the top phase is lower than that of the bottom phase,and the density of the top phase is smaller than that of the bottom phase.The length of the tie line(TLL)increases with the increase of the hydrogen bond basicity(?)of the ionic liquid.ILs are enriched in the top phase of the two aqueous phase,while K₃PO₄is enriched in the bottom phase.The optimal extraction parameters were obtained by using response surface as follows:aqueous two-phase extraction system([P₄₄₄₄]Br:K₃PO₄:H₂O=21%:17%:62%),extraction temperature 65?,extraction time 20 min.Under these conditions,the extraction yield of croctin was 14.28±0.18 mg/g,and the partition coefficient was 592.61.The purity and recovery of croctin were 65.43%and 44.37%after one precipitation.(2)Extraction of crocin by ionic liquid microemulsion system.The microemulsion phase diagrams of the three ionic liquids were drawn by water titration.The results showed that the larger the Km value was,the larger the microemulsion region was.The longer the alkyl side chain of ionic liquid,the larger the microemulsion region.The particle size of microemulsion composed of different ionic liquids is slightly different.[C₄mim]PF₆<[C₆mim]PF₆<[C₈mim]PF₆,The maximum particle size is 29.42±1.78 nm and the minimum is 8.62±0.95 nm.The effects of Km value,ultrasonic power,microemulsion compositions and temperature on the extraction yield of crocin were investigated.The results showed that the composition of microemulsion had the greatest influence on the extraction rate of crocin,while the influence of ultrasonic power was relatively small.The optimal extraction parameters were as follows:microemulsion system(IL_S:H₂O:surfactant=20%:30%:50%),Km value is 2,ultrasonic power is 180 W,extraction temperature is 60?.The optimal extraction yield was 17.09±0.02 mg/g.(3)The macroporous resin was used to separate and purify the crocin in microemulsion.The macroporous resin HPD100 had the best adsorption rate and elution rate of crocin.The kinetics of adsorption of crocin by macroporous resin showed that the equilibrium adsorption rate of crocin by macroporous resin increased with the increase of temperature.The data of adsorption isotherm are more consistent with Freundlich model,and R²is all greater than 0.98.The process flow of crocin in macroporous resin separation emulsion was determined.First,the surfactant(TX100)in the extraction system was removed by H103 macroporous resin,and then the crocin was separated by HPD100 macroporous resin.The gardenoside could be completely eluted by 20%ethanol solution at the flow rate of 1 BV/h and the elution volume of 3 BV,and the crocin was desorbed by 80%ethanol at the flow rate of 3BV/h and the elution volume of 3 BV.Due to the large amount of surfactant in the microemulsion,it is difficult to separate the crocin.The purity and recovery of crocin was 40.51%and 61.49%.(4)Gardenia yellow was used in the preparation of noodles.Xanthan gum,compound phosphate and?-cyclodextrin were used to improve the quality of noodles,When the addition amount of xanthan gum was 0.5%,Gardenia yellow noodles had the least breaking rate,the lowest cooking loss rate and the best quality.When the amount of compound phosphate was 1.0%,the breaking rate of gardenia yellow noodles was the lowest 3.33%,and the cooking loss rate was 4.2%.?-cyclodextrin had little effect on the cooking loss rate of gardenia yellow noodles.With the increase of the addition amount,the breaking rate and water absorption of the noodles showed an increasing trend.In the experiment of the storage stability of gardenia yellow noodles,it was found that cyclodextrin had little effect on the stability of gardenia yellow noodles.After 14 days of storage,the b^*value of gardenia yellow noodles prepared by gardenia yellow solution with different OD values decreased by 6.9%,9.6%,8.2%and 14.6%,respectively.The lower the OD value,the more stable the noodle color was,the noodles were not get green in all.