Studies On Extraction, Purification, Stability And Antioxidant Activity Of Anthocyanins From Red Cabbage

Red Cabbage ,also known as purple cabbage, is rich in vitamin C, vitamin E and vitamin B ,and abundant anthocyanins and cellulose,etc.The pigments in Red Cabbage belong to anthocyanins.Anthocyanins in Red Cabbage have many physiological functions such as,anti-oxidation,anti-mutation,prevent cardiovascular and cerebrovascular diseases,protect the liver, inhibit tumor cells,etc. Cyanidin-3-glucoside thereinto is an important biological activity substance, has functions of reducing blood serum albumen and lipide,it also had protection effect of oxidation damnification of the local anaemia liver.In this paper,the experiment used Red Cabbage (Dongnong-8D50)provided by College of Horticulture,Northeast Agricultural University, as raw material, to explore the process of extraction,purification and stability and antioxidant activity analysis of anthocyanins in Red Cabbage, extraction methods of anthocyanins in Red Cabbage with Harbin Zhengyang River rice vinegar were studied, to provide a theoretical basis for empoldering anthocyanins-rich rice vinegar products which can reduce blood fat and protect the liver.We first established analysis methods that are pectrophotometry method to measure content of anthocyanins , HPLC method to measure content of cyanidin in anthocyanins, adopted four measurements of antioxidant activity:·OH free radical scavenging activity measurement , O2- free radical scavenging activity measurement, DPPH free radical scavenging activity measurement, inhibition of linoleic acid peroxidation measurement.The anthocyanins in Red Cabbage were extracted by solvent extraction and ultrasonic-assisted extraction methods.The optimum conditions of solvent extraction through the single factor and orthogonal experiments were obtained,namely extracted for 2h by using 40% acetic acid solution at 30°C with the material-solution ratio of 1:4(g/mL), the extraction yield of this method was 3.02mg/g.The optimum conditions of ultrasonic-assisted method were obtained,namely extracted for 50 min by using 30% acetic acid solution at 40°C with the material-solution ratio of 1:4(g/mL),the extraction yield was 1.87mg/g.Compared the two methods,the extraction method of solvent extraction was better than the ultrasonic-assisted method,but longer extraction time than ultrasonic-assisted method.In this experiment,the macroporous resin was applied to the process of purification.By choosing HPD-300 macroporous resin as adsorbent.The appropriate absorption conditions were as follows, sample concentration 0.2mg/mL, velocity 1mL/min, adsorption temperature 20℃.Appropriate analytical conditions were as follows: elution solvent 40% ethanol solution, with a flow rate of 1mL/min. Purified extracts (calculated by cyanidin) were increased to 12.2%.Stability study showed that with increasing pH value, the maximum absorption wavelength caused red shift. In acidic condition,stability of anthocyanins was good. With pH value increasing, the pigment faded fast. Anthocyanins extracts under direct nature light faded fast,and slow under dark.. In acidic condition, the temperature of 80℃or less,the thermal stability of anthocyanins was good, at 100℃, anthocyanins of pH value 4.0 ~ 6.0 had poor thermal stability.Addition of Cu2+ , Mg2+ , K+ , Zn2+ , Ba2+, Fe3+ caused decline of stability, Fe2+ had little effect.Saccharose,fructose,glucose all caused stability enhancement.Addition of tartaric acid and citric acid enhanced the stability of anthocyanins. Addition of Vc didn't cause adverse effect. Addition of H2O2 caused decline of stability.In this paper, antioxidant activity of anthocyanins in Red Cabbage were studied. The results showed that, anthocyanins in Red Cabbage had antioxidant activity, DPPH free radical scavenging activity(72.2%),and·OH free radical scavenging activity(82.5%), O2- free radical scavenging activity is better than Vc,linoleic acid peroxidation inhibiting activity(47.6%).Extraction method of anthocyanins in Red Cabbage with Harbin Zhengyang River 9°rice vinegar were studied, The optimum conditions of ultrasonic-assisted extraction were obtained,namely extracted for 30min at 40℃with the material-solution ratio of 1:3(g/mL). The extract was namely rice vinegar of blood fat reduction and liver protection. the content of Cyanidin in the product was 0.3 mg/mL .Through determining antioxidation activity, indicated that the antioxidant ability of the product and Vc at the same concentration was similar.