Study On Ultra High Pressure Assistant Extraction Of Anthocyanins From Aronia Melanocarpa And Its Stability

Aronia melancarpa is a precious species which well boasts edible,medicinal,ornamental and ecological values,with its fruit abundant in anthocyanins.Because of the great antioxidation,anthocyanins have a variety of function in physiology and healthcare in terms of free radicals scavenging,livers and eyesight protecting,anti-tumor,anti-inflammation,anti-cancer,etc.Therefore,there is a great potential application prospect in health-care products as well as drugs,and it is very necessary to find an extraction method to increase anthocyanins' extraction efficiency and maintain its bioactivity.Scientific researches have shown that the ultrahigh pressure-assisted extraction(UPE)technology has the abilities to enhance yield and activity of bioactive components.This thesis,based on Aronia melancarpa as the raw material,the effects of ultrahigh pressure technology on the anthocyanins'extraction efficiency,monomer content stability and antioxidant activity were studied,compared with solvents extraction.The main conclusions are as follow:(1)The results of effects of ultrahigh pressure-assisted extraction on anthocyanins of Aronia melancarpa.This study initially evaluated the optimum extraction conditions of ultrahigh pressure-assisted technology by response surface methodology,with the base on single-factor experiments.The optimum processing conditions were determined as follows:solid-liquid ratio 1:22(g/mL),UPE time 12 min,extraction pressure 410 MPa.The extraction yield of Aronia melancarpa reached 486.12 mg/100g under the best condition,compared with the solvent extraction method acquired from references which was 412.16 mg/100 g.(2)HPLC and HPLC-MS were applied to analyze and preliminarily identify the components of Aronia melanocarpa.Three monomers of the anthocyanins were identified as follows:cyaniding-3-galactoside,cyaniding-3-arabinoside,cyaniding-3-xyloside.The comparison of extraction methods' effects between UPE and solvents on the content of the same anthocyanin monomer was detennined as follows:The percentages of cyanidin-3-galactoside accounted for the total anthocyanins extracted by UPE and solvents were 73.08%and 76.39%,respectively.22.35%of the total anthocyanins was cyaniding-3-arabinoside extracted by UPE and 20.57%by solvents.Cyaniding-3-xyloside made up 4.57%of the total anthocyanins by UPE and 3.04%by solvents(3)The results indicated that the stability of anthocyanins of Aronia melancarpa was affected by pH level,temperature,light,oxidants,reductants,metal ions as well as food additives to some degree The anthocyanins' stability extracted by UPE was better than that extracted by solvents under the condition of same content of anthocyanins.(4)There was a big difference between UPE and solvents under different storage conditions in terms of the retention ratio and antioxidant activity of anthocyanins through the juice simulation system.The result showed the retention ratio of anthocyanins extracted by UPE was higher than that extracted by solvents,with the same trend in antioxidant activity.Moreover,the longer it stored,the bigger difference between UPE and solvents was.