Study On The Effect Of Mulberry Leaf Volatile Oil Active Ingredients On The Preservation Of Fruits And Vegetables

Plant volatile oils are secondary metabolites in plants,the chemical composition is complex,low boiling point and easy to evaporate,with non-toxic,antioxidant,antibacteriial and other characteristics,plant volatile oils are unique natural fruit and vegetable preservatives.Mulberry Leaf,belonged to the Moraceae,has been used as a drug since the Eastern Han Dynasty.Early studies show that,Mulberry Leaf has a variety of pharmacological activity,such as expelling wind,removing liver fire for improving eyesight,protecting joints,diuresis,hypotensive,eliminating stasis to resolve swelling.China hasa a wealth of Mulberry resources and some of which are used as feed for sericulture,and most of the rest are burned,causing waste of resources and irrational use.The study of Mulberry Leaf in recent years has been focused on total flavonoids,total alkaloids,total polysaccharides,etc.But on Mulberry Leaf volatile oil is very few.The research took Mulberry Leaf essential oil as our research object,studied the optimization of extraction the oil conditions,and also studied the scavenge free radicals antibacterial effect,and explored the application of fresh fruies and vegetables afford theoretical basis for depth development Mulberry Leaf,also had certein significance for China's pure plant resources in the research direction of fruies and vegetables preservation.In the paper,the steam distillation extraction was used to extraction rate,studied extraction process of the steam distillation extraction,the results showed that,the base combination of conditions:Crush degree was 60 mesh,solid-to-liquid ratio was 1:9,soak time was 7 hours,extraction time was 9 hours.The antioxidant activity activity of Mulberry Leavf volatile oil was studied.The results showed that Mulberry Leaf volatile oil has certain scavenging ability for DPPH radical,superoxide radical and hydroxyl radical,and increases with the increase of the concentration of volatile oil in Mulberry Leaf.The results showed that 10%of the oil solution of DPPH clearance rate was as high as 91.4%,clearance rate of O₂^-was 88.6%,clearance rate of�OH was 59.2%.Under the same concentration,the free radicals removal ability order was DPPH>O₂^->�OH.The antibacterial activity activity of Mulberry Leavf volatile oil was studied.The volatile oil of mulberry leaves has a certain inhibitory effect on Staphylococcus.aureus,Eumychyta,Bacillus.Subtilis.The minimum bacteriostatic concentractions of the oil for various microbes were as follow:Staphylococcus.aureus 12.5?L/mL;Bacillus.Subtilis 6.25?L/mL;Eumychyta 6.25?L/mL.Use Mulberry Leaf volatile oil for corrosion test on fruits and vegetables,select six kinds of fruits and vegetables?grapes,pears,kiwi,cucumbers,tomatoes and green peppers?,by measuring the fruit hardness,soluble sugar content,MDA content,SOD,PAL,POD enzyme activity to study the effect of Mulberry Leaf volatile oil on the preservation of fruits and vegetables.The results of fruit firmness showed that the hardness of five kinds of fruits and vegetables in the test group was greater than that of the control group at 14 days,show that the volatile oil of Mulberry Leaf can retard the decrease of fruit hardness.The results of the soluble sugar content of fruits and vegetables show that from the 14th day onwards,the trend of decreasing soluble sugar content of fruits and vegetables in the experimental group was significantly slower than that of the control group.The results of malondialdehyde content in fruits and vegetables show that the volatile oil of mulberry leaves can effectively prevent the rate of peroxidation of membrane lipids and increase the content of malondialdehyde.The results of studies on superoxide dismutase,phenylalanine ammonia-lyase,and peroxidase showed that the volatile oil of mulberry leaves can effectively inhibit thedecrease of superoxide dismutase activity and phenylalanine ammonia-lyase activity and delay the growth of fruits and vegetables.The rate of decay caused by lignification significantly inhibited the increase of peroxidase and prolonged the defense time of fruits and vegetables against external stress.GC-MS analysis of the composition and content of the volatile oil from Mulberry Leaf,a total of 77 chemical components were identified:analyzing the chemical constituents in the volatile oil of mulberry leaves,we can see that there are ingredients that can effectively inhibit the propagation of rot fungi caused by fruits and vegetables,such as nerolidol,geraniol,carveol and limonene.There are components that can exert a certain bacteriostatic effect by destroying the bacterial redox system,such as geranyl geranone,damasceneandlarge-leafterpenes.Thecomponentsof citral,phenylacetaldehyde and benzaldehyde also have obvious inhibitory effects on the growth and sporulation of fungi.Butylated Hydroxytoluene and other phenols can affect bacterial intrusion by inhibiting bacterial protein synthesis.