The Research On Effect Of Fruits (Such As Strawberry) Preservation And Mechanism Of Mulberry Leaves Compound

In the study, through using compatibility theory of Traditional Chinese Medicine(TCM), mulberry leaves, folium artemisiae argyi, dandelion and mint were selected as a compound and chitosan as a film-forming agent. The proportion of mulberry leaves compound was optimized through the orthogonal experiment which regarded the weight loss rate as index; The effect on preserving different types of fruits (strawberry, grape and pear) was indicated by the index of the weight loss rate and nutriment such as Vitamin C, soluble solids and titratable acid; The mechanism of fruit preservation and active ingredient was further researched.The key results are shown as below.1. Through the three factors and three levels orthogonal experiment, the compound were made up with chitosan and then used to keep strawberries fresh. The weight loss rate of strawberry treated with the compound coating agent were determined to analyze and optimize the optimal formulation of the compound as the mulberry leaves37.5g, folium artemisiae argyi37.5g, dandelion12.5g and mint10.Og. The compound mixed with chitosan was used to preserve strawberry, grape and pear which can effectively reduce three kinds of fruits weightlessness, slow the degradation speed of Vitamin C, soluble solids and titratable acid, so it played a significant effect on fruit preservation.2. The mechanism of fruit preservation and active ingredient of mulberry leaves compound was researched. The method of cutting a single drug of mulberry leaves compound was used to study the abilities of anti-oxidation and tyrosinase inhibition, the contents of polysaccharides, flavonoid and polyphenol. Software SPSS was used to analysis the correlation. The results that the Compound was more effective than the other Compositions on antioxidant and tyrosinase inhibition; The content of flavonoid and polyphenol had a significant positive correlation with the anti-oxidation, and the content of flavonoid had a significant negative correlation with the inhibition of tyrosinase; the folium artemisiae argyi and mulberry leaves respectively played a main role in anti-oxidation and tyrosinase inhibition could be concluded.3. The mechanism of inhibiting tyrosinase was further researched. The mulberry leaves compound had the inhibition abilities of monophenoloxidase and diphenoloxidase. The mechanism was defined as a reversible mixed-type by Lineweaver-Burk plot. And the KI and KIS value was5.71mg/ml and7.24mg/ml, KI<KIS, meant the inhibition effect on free enzymes of Compound extract was stronger than that on enzyme-substrate complex which was between competitive and noncompetitive inhibition. In the process of inhibiting diphenoloxidase, with increasing in concentration of L-dopa protected the enzymes.The experimental results that TCM compound extract had an effect on keeping different types of fruit fresh, which achieved from its anti-oxidation and tyrosinase inhibition were confirmed. The results laid the foundation for the development of TCM compound used to preserve fruit.