Processing Technology And Functional Properties Of Black Chokeberry(Aronia Melanocarpa Elliot.) Fruit Juice

In this study,black chokeberry fruit was used as raw material,and the composite enzyme of pectinase and cellulase was used as the enzyme preparation to prepare the black chokeberry juice by the enzymatic liquefaction technology.More than that the preparation process conditions were optimized.Based on this,the effects of different treatment conditions on the bioactive components and physicochemical properties of the black chokeberry fruit juice were investigated.The antioxidant and enzyme kinetics of the fruit juice under different treatment conditions were explored preliminarily.The obtained results were as follows(1)The effects of K2SO3 inhibitors and steam blanching on the polyphenol oxidase in the fruit of the black chokeberry were studied.The results indicated that the treatment of steam blanching for 2 min could completely inactivate polyphenol oxidase and effectively inhibit the enzymatic browning of juice(2)The effects of ratio of composite enzyme,enzyme amount,temperature,and time on the juice yield,proanthocyanidins and anthocyanins content of black chokeberry juice were investigated.Based on the research of single factor,box-Behnken response surface model was employed to optimize the optimum technological parameters for enzymatic hydrolysis of the black chokeberry juice with the content of proanthocyanidins and anthocyanins as indicators.The optimum process parameters for the enzymatic hydrolysis of the black chokeberry were given below:the ratio of composite enzyme was 0.78,the amount of enzyme was 0.06%,temperature was 45?,and time was 3.56 hours.The fruit juice rate of the black chokeberry fruit was 78.65%under the optimal conditions,The proanthocyanidins content in the black chokeberry fruit juice was 1679.85mg/100g,and the relative error from the model prediction was 0.684%.The anthocyanins content was 187.91 mg/100g.and the relative error from the model prediction was 1.786%.(3)The effects of different treatment conditions on the bioactive components and physicochemical properties of the black chokeberry fruit juice were studied.The results indicated that compared with the juice without enzyme treatment,the juice prepared by enzyme treatment increased the content of proanthocyanidins by 78.41%,the anthocyanins increased by 96.82%,the phenolic acids increased by 40.13%,and the flavonoids increased by 35.99%.The contents of basic nutrients such as soluble sugar and vitamin C were increased,the stability of the juice was enhanced,and the color and lustre of juice was more brighter.(4)The effects of different treatment conditions on the antioxidant activity of the black chokeberry fruit juice was researched.These findings indicated that the black chokeberry fruit juice showed strong elimination and inhibition ability on DPPH free radicals,total reducing power,superoxide anion,hydroxyl radicals,lipid peroxidation,free radical ABTS and nitrite system.And its antioxidant capacity was gradually increased with the increase of juice concentration.Compared with the non-enzyme treated fruit juice,the enzymatic hydrolysis of pectinase and cellulase enhanced the antioxidant capacity of the juice.(5)The effects of different processing conditions on the enzyme kinetics of the black chokeberry fruit juice of was studied.The results showed that the fruit juice treated with enzyme illustrated a more significant effect on the activities of a-amylase,a-glucosidase,tyrosinase,xanthine oxidase,alcohol dehydrogenase and acetaldehyde dehydrogenase than those without enzyme treatment.These findings indicated that black chokeberry fruit juice will have a place in the application of functional food materials,such as auxiliary hypoglycaemia,freckle whitening,gout control and alcohol-induced liver injury.