Development And Research Of Gardenia Pigments

Our country is rich in Gardenia resources, especially in recent years, the natural pigment industry has a very good development trends, development and application of Gardenia pigment has become a hot spot. The purpose of this research is to improve multipurpose utilization of Gardenia fruits. Making full use of geniposide produced as byproduct from the extraction of yellow pigment as material to prepare Gardenia blue pigment and red pigment. To discuss the preparation of Gardenia blue pigment and red pigment by immobilized enzyme, and to study the purification and concentration process of pigments by precipitation, then further to explore physicochemical property of Gardenia pigment.The main research content were as follows:（1） The study selects concentration of sodium alginate, VEnzyme/VSodium alginate, concentration of CaCl₂ and immobilized time as the influencing factors, builds the corresponding two-order polynomial equation by Box-Behnken experiment design method. And by the equation, the optimum conditions for the immobilization process are obtained. The highest rate of immobilized of cellulose is 59.686% in the condition of sodium alginate concentration 2.97%, VEnzyme/VSodium alginate 1:5, CaCl2 concentration 1.91% and immobilized time 1.67h. And the stability of the immobilized enzyme is better than free cellulose. By re-use 20 times the activity of mmobilized enzyme retains more than 45%. In the 1L continuous hydrolysis process, the enzymolysis effect is best when the flow rate at 1.0ml/min.（2） The best condition for preparation of Gardenia blue pigment by immobilized enzyme is: reaction temperature 50℃, the flow rate 1.0ml/min, reaction time 60h, amino acids and glycosides mass ratio 5:10. The best condition for purification and concentration is: Al3+solution concentration 0.01mol/L, concentration rate 70%. By comparison with the existing technology, this study develops a new technology for preparation of Gardenia blue pigment, and has certain advantages at E590nm, the utilization of enzymes, the reaction cycle and energy consumption.The molecular weight distribution of Gardenia blue pigment is near 190kDa, analyzed by HPGPC. And in the reaction process, with creasing of the reaction time, the molecular weight distribution of Gardenia blue is increasing gradually.（3） HPLC conditions of Gardenia blue pigment is established. Column: Waters Ultrahydrogel linear column. Mobile phase: 0.1 mol/L NaNO3 solution. The molecular weight distribution of Gardenia blue pigment distributes 45.5kDa nearby, analyzed by HPGPC. And in the reaction process, with creasing of the reaction time, the molecular weight distribution of Gardenia blue is increasing gradually.（4） The best condition for preparation of Gardenia red pigment by immobilized enzyme is: reaction temperature 50℃, the flow rate 0.5ml/min, reaction time 60h, amino acids and glycosides mass ratio 5:10. Then, purification and concentration by acid precipitation, the E540nm （1%） of Gardenia red pigment increases from 46 to 197. Comparing with the existing technology, there are certain advantages of the new technology for preparation of Gardenia red pigment that developed in this study.（5） The maximum absorption wavelength of Gardenia red pigment is obtained at 540 nm. IR results show that Gardenia red pigment may retains the aromatic ring structure, and Ar-OH is formed. The molecular weight distribution of Gardenia red pigment is determined near 38.6kDa by HPLC, and use 0.1 mol/L NaNO3 solution as the mobile phase. Gardenia red pigment has good stability while pH > 3, precipitate appeared if pH value was less than 3. The alkaline environment can protect the color of pigment at certain extent. Gardenia red pigment is stable with these additives, temperature, Na⁺, K⁺, Fe²⁺, Mg²⁺, Ca²⁺, Zn²⁺ and is highly resistant to reduction, but not to light, oxidation and Fe³⁺, Cu²⁺, Al³⁺, Sn²⁺.