The Research Of Physical And Chemical Properties Of Anthocyanin Comounds In Red Cabbage And Applied In Analytical Chemistry

Based on the red cabbage as raw materials, solvent extraction and ultrasonic extraction baptized two methods of extracting anthocyanins were studied. The optimal extraction conditions of two methods were respectively determined, comparing the advantages and disadvantages of the two methods. The physical and chemical properties of anthocyanins were studied, including the stability and pH of anthocyanins metal ion to the influence of anthocyanins, the influence of anthocyanins, antioxidants and to the influence of reductant. Finally, to explore the nature of food additive effects of anthocyanins.The results show that:(1) The optimal conditions of Solvent extraction of red cabbage anthocyanins extracted emulated:best extraction solvent10%ethanol, optimum temperature50℃, best material to liquid0.6g/25mL, best extraction time90min.(2) The optimal conditions of Ultrasonic extraction method for anthocyanins:best extraction solvent water, optimum temperature50℃, best extraction time60min. best ultrasonic power is100%(777w).(3) The stability of anthocyanins extracts in room temperature hold time is generally72h, in lower temperature it is able to maintain a longer time.(4) When the pH<3, the anthocyanins show the red, pH3～10, the anthocyanins present in purple, When the pH>10, the anthocyanins becomes blue, even green and yellow, In the4-9pH range stability of the fluorescence intensity of anthocyanins, When pH <4or pH>9fluorescence intensity decreased.(5) Na+, K+and other ions have little effect on the fluorescence properties of anthocyanins, however, Cu2+, Pb2+, Cr3+, on the fluorescent properties of the plasma will affect.(6) Oxidant hydrogen peroxide greater impact on the anthocyanins, The higher the concentration, the smaller the anthocyanins absorbance. The reducing agent on the absorbance of anthocyanins is smaller.(7) Absorbance of sucrose on anthocyanins food additives less affected, while the citric acid of the larger.A new method of the quantitative determination of Al3+was created basing on the different color between anthocyanin itself extracted from the red cabbage and the product of the complexation that Al3+reacting to anthocyanin. Anthocyanins colored with Al3+in acetic acid-sodium acetate buffer at pH4.7. The maximum absorption wavelength of the complex was580nm. There was well linear relationship between absorbance and Al3+of which content is in the range of0.1-1.0mg/25mL, correlation coefficient R2=0.9995. The molar absorption coefficient of complex is236L· mol-1· cm-1. The precision of replicate measurements was2.13%at Al concentrations of25μg·mL. A quantitative solution detection limit of0.059mg/25mL-1was obtained. The analytical procedure was critically evaluated by analysing certified soil reference materials (GBW07408) and determining the recovery of Al in the materials. Excellent agreement between the experimental values and the certified concentrations and the optimum recoveries of98%～109%by addition of the standard solution in the digestion solution of the soil reference materials was obtained. Because of less interference ions, short colored time, stable complex, accurate and reliable characteristics, this method can be used for the quantitative determination of trace amounts and low levels of aluminum.A new method of the quantitative determination of Fe(Ⅲ) was created basing on the different color between anthocyanin itself extracted from the red cabbage and the product of the complexation that Fe(Ⅲ) reacting to anthocyanin and CTMAB.In the presence of3.5g· L-1cationic surfactant CTMAB, Anthocyanins colored with Fe(Ⅲ) in acetic acid-sodium acetate buffer at pH4.7. The maximum absorption wavelength of the complex was620nm. There was well linear relationship between absorbance and Fe(Ⅲ) of which content is in the range of0.1～1.0mg/25mL, correlation coefficient R2=0.9989. The molar absorption coefficient of complex is2.0×103L· mol-1· cm-1. The precision of replicate measurements was1.84%at Fe concentrations of25μgmL. A quantitative solution detection limit of0.023mg/25mL was obtained. The analytical procedure was critically evaluated by analysing certified rock reference materials (super mafic rocks DZE-2) and determining the recovery of Fe in the materials. Excellent agreement between the experimental values and the certified concentrations and the optimum recoveries of95.6%～107.7%by addition of the standard solution in the rock reference. After anthocyanin extracted from red cabbage was purified by macroporous resin,a new method of dual-wavelength to determine iron and aluminum simultaneously in the soil was established basing on the difference of maximum absorption between anthocyanin-Fe and anthocyanin-Al being45nm. Anthocyanins colored with Fe(Ⅲ) and Al(Ⅲ) in acetic acid-sodium acetate buffer at pH4.7. There was well linear relationship between absorbance and Fe(Ⅲ) and Al(Ⅲ) of which content is in the range of0.1～1.0mg/25mL, correlation coefficient:The molar absorption coefficient of complex is:The precision of replicate measurements was RSD585nm=0.57%, RSD630nm=0.91%at Al3+and Fe3+concentrations of25μg·mL. A quantitative solution detection limit of was obtained.The analytical procedure was critically evaluated by analysing certified soil reference materials (GBW07408) and determining the recovery of Al and Fe in the materials. Excellent agreement between the experimental values and the certified concentrations and the optimum recoveries of Fe95.4～108.1%, Al96.1～108.0%98%～109%y addition of the standard solution in the digestion solution of the soil reference materials was obtained.