Study On The Technology And Efficacy Evaluation Of Compound Juice Of Aronia Melanocarpa

Aronia melanocarpa is a new kind of small berry.In recent years,it has been introduced into China and mainly planted in Northeast China and Liaoning Province.Its fruits are rich in anthocyanins,which is a precious crop integrating food and medicine.In this paper,the processing technology of compound juice of Aronia melanocarpa was optimized,the dynamic model of the storage period of compound juice under different sterilization methods were analyzed,the storage period prediction model of compound juice of Aronia melanocarpa under different sterilization methods was established,and the flavor stability of the compound juice under different sterilization methods was studied.The main conclusions are as follows:For the enzymatic hydrolysis process,taking juice yield as evaluation index,the optimum enzymatic hydrolysis conditions of Aronia melanocarpa juice were 0.04%pectinase and 0.02%cellulase based on the single factor and response surface optimization experiment,enzymatic hydrolysis temperature 50℃,enzymatic hydrolysis time 2 h,the final juice yield of Aronia melanocarpa was 75.58%.For the study of color protection process,taking browning degree and total color difference(ΔE)as the evaluation index,On the basis of single factor and orthogonal experiment,the optimum technological conditions for color protection were obtained as follows:0.4%ascorbic acid(Vc),0.1%citric acid and color protection time 2 h.For clarification process research:taking the transmittance as the main evaluation index,the best compound clarification conditions are obtained by single clarification and compound clarification experiments:first clarification with chitosan(adding amount was 2%,clarification temperature is 50℃,clarification time is 1 h),then clarification with pectinase(adding amount was 0.4%,clarification temperature is 50℃,clarification time is 2.5 h).The final transmittance was 61.39%,On the basis of composite clarification,the best clarification effect of the membrane was NFC-50,and the final transmittance of the juice was 77.82%.For the study of the compound technology,the sensory quality was the main index,through sensory evaluation experiment,the optimum combination conditions were:Aronia melanocarpa juice:concentrated jujube juice:concentrated apple juice ratio was 6:1:0.5.After pasteurization,boiling sterilization and UHT sterilization respectively,the changes of total anthocyanins content,Ho and color sensory evaluation value of compound juice of Aronia melanocarpa in different sterilization conditions were studied.The results showed the changes of total anthocyanins content,color phase angle(Ho),and color sensory evaluation value under different sterilization conditions were followed the first-order reaction,and the linear relationship between the three indicators fits well.Taking the total anthocyanin content as the quality change factor,the storage period prediction model was obtained.Flavor stabilization of fruit juice before and after different sterilization methods was studied by Gas chromatography-mass spectrometry(GC-MS).The results showed that after UHT sterilization,not only greatly retained the flavor of the original juice,but also produced a variety of new ester substances,which increased the aroma of the juice.The efficacy was evaluated by measuring DPPH scavenging free radical ability,ABTS+scavenging free radical ability and superoxide anion scavenging free radical ability.