Effects Of Different Heat Treatments On The Content Of Anthocyanin Extract And Antioxidant Activity

Anthocyanins,the member of the “flavonoid” family of natural products,exist in plant food widely and perform as a kind of water-soluble natural pigments and powerful antioxidants which could protect human against the free radical damage.However,anthocyanins are easy to be degraded under the effect of temperature,light and p H during the manufacturing process.This paper selected purple potato,which is rich in the main anthocyanins,as the material to mainly study on the following points : First,the different extraction methods of anthocyanins from purple potato were compared to obtain the most efficient and economic one,as well as the conditions of purification were optimized.Then this paper determined the effects of different treatments including microwaving,steaming,boiling,and frying on the changes of structure and antioxidant activities of anthocyanins in a simple food system consisting of cellulose and the purified anthocyanins extraction of purple potato.Furthermore,the effect of anthocyanin product on hepatocyte function was evaluated through examining Liver cell viability and antioxidant enzymes.Moreover,the antioxidative capacity and safety of the processed food rich in anthocyanins are investigated by the cell-based1.The main research results were as follows:1.Comparing the three conditions of extraction basing on the contents of extractable anthocyanin,the result of ultrasonic assisted extraction was best,then was room temperature extraction,and water bath heating extraction was worst.Takin the convenience of operation into consideration,this paper selected the room temperature extraction to conduct the extraction of anthocyanin.2 The crude extract was subjected to macroporous adsorption resins and the best purify was got when the eluent concentration(methanol)elution was 100% and the elution was rate 4 m L/min.3.Study the effects of four kinds of thermal processing on the simple simulation system against oxidative composition and antioxidant activity.Results show that microwaving,the anthocyanins.Polyphenols,flavonoids and antioxidant activity also was decrease in high power while in the rest power,content was increased first and then decreased.The content of anthocyanin,polyphenol and flavonoids and antioxidant activitywas decreased with steaming time.In the case of p H4,the performance was most stable.The effect of different ion concentration on cooking process is different.All the substances under Cu ion are reduced;Under the action of Fe ion,anthocyanin was decrease continuously,while the others was increased continuously at 0 and 2 mmo/L,and then was decreased at a higher concentration.Ions have a certain effect on both ions and the greater the concentration,the greater the influence.Under the condition of Al and Na ions,ions have little influence on them,and the degradation law was consistent with that of Fe ion.During frying,anthocyanin is continuously degraded,polyphenol was increased,and flavonoids content and antioxidant activity are reduced in the whole process.4 Total 10 components of anthocyanins from purple potato were identified according to the mass spectra and literature:cyanidin-3 – p –hydroxybenzoylsophoroside – 5 – glucoside,? peonidin-3 – p –hydroxybenzoylsophoroside–5–glucoside,?peonidin-3–(6?–feruloylsophoroside)–5 – glucoside? cyanidin-3 –(6 – caffeoyl – 6 – feruloylsophoroside)–5 –glucoside ? cyanidin-3 – caffeoyol – p – hydroxybenzoylsophoroside – 5 –glucoside?cyanidin 3–(6 – caffeoyl–6–feruloylsophoroside)–5–glucoside?peonidin 3–caffeoyol–p– hydroxybenzoylsophoroside–5–glucoside?peonidin 3–(6–caffeoyl–6? –feruloylsophoroside)–5–glucoside? It was observed by HPLC that the content of anthocyanins was reduced after dealt with different heating processions,which meant the degradation of anthocyanins happened.The degradation abilities of microwaving and frying were stronger than that of steaming and boiling but all can totally decompose anthocyanins after a long time procession.The degradation products were not detected on 280 nm by HPLC,suggesting that such products were the same as original phenolics in purple potato or they didn't have characteristic absorption on 280 nm.5.The effects of different heat treatment on liver cell activity and different enzyme activities were consistent,and had a certain relationship with antioxidant activity.Among them,microwaving and steaming reduce the activity gradually.However,the boiling increased the activity.The effect of boiling was the least,followed by evaporation,while the microwave effect was greater.In the end,the influence of microwave processing is more complex.