Study On Construction And Properties Of Anthocyanin Hydrogel System

The blueberry industry is the world’s second largest berry industry.In recent years,blueberries have attracted much attention because of their good biological activity.Anthocyanins(Ans)are the main bioactive components in blueberries,which have important research value.Anthocyanin is a kind of natural water-soluble pigment,and also a kind of natural antioxidant,with anti-inflammatory,lipid regulation,blood pressure regulation,blood sugar regulation and other functions,has a broad application prospect in the food industry.However,anthocyanins are susceptible to p H,microorganisms,and various enzymes,leading to structural destruction and thus reducing the bioavailability of anthocyanins in vivo.Hydrogel can improve the stability of embedded materials,and has excellent biocompatibility and biodegradability,and has a wide range of applications in drug release,tissue engineering and other aspects.Therefore,this paper intends to improve the environmental stability and in vivo bioavailability of anthocyanins through hydrogel embedding technology,and provide scientific basis for further development and utilization of anthocyanins.The main work of this paper is as follows:1.Screening of anthocyanin hydrogel carrier materials and preparation of anthocyanin hydrogel.First prepared by freeze-drying method,gellan gum and xanthan gum and carrageenan gelatin hydrogel,and liquidity of four kinds of hydrogels,apparent viscosity,gel strength and swelling degree were determined,the results showed that xanthan gum,larger kara glue is bad for the preparation of compound hydrogel,and gelatin,gellan gum has appropriate viscosity,gel strength,And it has the appropriate swelling degree in the simulated gastrointestinal digestive fluid.Therefore,gelatin and gellan gum were selected as carrier materials to prepare anthocyanin hydrogel in this study.2.Determination of anthocyanin hydrogel embedding efficiency and observation of anthocyanin distribution in hydrogel.In this study,the compound ratio of gelatin/gellan gum was 10:0(H0),9:1(H1),8:2(H2),7:3(H3)and 6:4(H4),respectively.Except for H0 hydrogel without gellan gum,the anthocyanin embedding efficiency of H1,H2,H3 and H4 composite hydrogels was higher than 85%.The results showed that anthocyanins were successfully embedded in the hydrogel,as H2 composite hydrogel had the highest embedding efficiency(96.75± 1.74%),and the distribution of anthocyanins was detected by fluorescence microscope.3.Structural characterization of anthocyanin hydrogel.Fourier transform infrared spectroscopy(FTIR),X-ray diffraction(XRD)and thermogravimetric analysis(TGA)showed that gelatin/gellan gum composite hydrogels increased the maximum weight loss temperature and crystallinity of anthocyanins in H2 composite hydrogels.The red shift of o-H absorption peak of complex hydrogels suggests that non-covalently bonded hydrogen bond may be the main interaction mode between gelatin and gellan gum.In addition,characteristic absorption peaks of gelatin,gellan gum and anthocyanins were reflected in Gel/ Gen-Ans absorption spectra,indicating the successful introduction of anthocyanins into hydrogels.4.Stability analysis of anthocyanin hydrogel.The gelatin/gellan gum composite hydrogels improved the storage stability of anthocyanin,and anthocyanin hydrogels retained a higher anthocyanin content when stored at 4℃ and 37℃ for 30 days,in which H2 was the highest(90.7% and 87.4%,respectively).Digestion stability experiment showed that after 4 h of simulated gastrointestinal digestion,anthocyanin content in H1,H2 and H3 hydrogel groups was still higher in intestinal digestive fluid,indicating that anthocyanin hydrogel realized controlled release of anthocyanin in simulated digestive fluid.Therefore,gelatin/gellan gum composite hydrogels can improve the bioavailability of anthocyanins in vivo.5.Explore the possible mechanism of anthocyanin hydrogel to improve the stability of anthocyanin.Gelatin/Gellan gum can form a dense three-dimensional network structure.By analyzing the apparent morphology,gel strength,loss modulus and swelling degree of hydrogels with different proportions,the results show that H1,H2 and H3 hydrogels have more dense gel network structure.After simulated gastrointestinal digestion,the H1,H2 and H3 hydrogels groups had higher anthocyanin content in intestinal digestive fluid,indicating that the controlled release effect of anthocyanin may be positively correlated with the compacting degree of complex hydrogels.6.Biocompatibility evaluation of hydrogel.The results of AO-EB experiment showed that IEC-6 cells showed uniform bright green fluorescence and no obvious red fluorescence after incubation in compound hydrogel for 24 h,48 h and 72 h,indicating that compound hydrogel treatment did not cause IEC-6 cells apoptosis.CCK-8 showed that the compound hydrogel did not inhibit the proliferation of IEC-6 cells,which was consistent with the results of AO-EB experiment.The above two biocompatibility experiments showed that the anthocyanin hydrogel prepared with gelatin/gellan gum as carrier material had almost no cytotoxicity and high safety.Therefore,gelatin/gellan gum composite hydrogels can be used in the future food industry.