Study On The Interaction Of Gelatin And Polyphenols

There are a lot of phenolic hydroxyl groups in plant polyphenols which are rich in tea, vegetables，fruits, grains and other plants.With people paying more and more attention on the awareness of healthy diet,more studies on polyphenols are being done. Much more research is on how to extract and purify polyphenols from plants and how to remove polyphenols from fruit or vegetable juice to improve its stability. There is few reports about the utilization of polyphenols. In this paper, the interaction of gelatin and polyphenols is studied aiming at utilization of plant polyphenols technical foundation.Complex reactions respectly among gelatin and kinds of polyphenol like epigallocatechin gallate (EGCG), punicalagins, proanthocyanidins, polyphenols chlorogenic acid are studied with the factors of gelatin concentration, reaction time, polysaccharide’s amount. Gelatin microspheres are prepared with the method of emulsion and cross-linking. Adsorption properties of gelatin microspheres for polyphenols are preliminarily studied with the factors of mass ratio of microspheres/polyphenol, the time, the temperature. Take EGCG for example, the polyphenols adsorbed by microspheres are desorped by the method of high-temperature water bath, and gelatin microspheres are reused for10times. There are some main results as following:1. In the complex tests between gelatin and polyphenols, it showed that, as the concentration of polyphenol is0.88mg/mL and volume ratio was1:1, the complex didn’t occur to form precipitate until the concentration of gelatin solution was0.2-20mg/mL. The reactions of complex were obvious among gelatin/EGCG, gelatin/punicalagins and gelatin/proanthocyanidin.2. It showed that, with the adding of sugar, pectin, xanthan gum respectly, polysaccharide’s impact on the complexation reaction was enhancing.3. Preparation of gelatin microspheres: the precise amount of liquid paraffin30mL in250mL conical flask, added450μL0.05g/mL Span80and stirred. Water bath was heated to55~60℃,10mL0.05g/mL of gelatin solution were added, emulsified under60℃for10min. Then ice bath till the temperature dropped to below10℃,50μL50%glutaraldehyde was added with the ice bath removing, cured for2h.Washed with acetone for3-4times, the microspheres prepared was immersed in10mL acetone to stand for some time under4℃, filtered acetone off and dried them to get the ones.4. The pH was3.5, the time was120min and the optimum temperature was35~45℃in the system of adsorption of Gelatin microspheres for polyphenols. The amount of polyphenols adsorbed by per mass microspheres could reach to the maximum while the mass ratio of polyphenols/microspheres was1:1. When the mass ratio was1:5, the adsorption rate of gelatin microspheres was54.86%for EGCG,78.01%for punicalagins,54.94%for proanthocyanidins and7.42%for chlorogenic acid.5. Take EGCG for example, the desorption rate of microspheres for the adsorbed polyphenols could be to100%when the ratio was1:0.5with the method of high temperature water bath. Gelatin microspheres were repeated using for10times and could be achieved respectively till the8th time. The adsorption rate was up to72.6%at the4th and the highest desorption rate was62.5%.