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Mallus doumeri is a kind of rosaceae and malus plant. There are many active ingredient in Mallus doumeri, and it has many kinds of functions such as anticancer effect, bacteriostasis, antioxidation, and etc. At present, the researches of Mallus doumeri focus on the developments of health functions and the evaluation of antibacterial effect in vitro. In this research, Mallus doumeri leaf was used as the material, the technical conditions of microwave-assisted extraction on the antiseptic compositions of Mallus doumeri Leaf were optimized. Moreover, the evaluation of experiment in vitro was conducted, the activity of bacteriostasis and antioxidation and the application in food of the antiseptic compositions from Mallus doumeri Leaf were studied.In the research of the antiseptic compositions which come from Mallus doumeri Leaf by Microwave-assisted Extraction, Model was constructed through uniform experimental, and the regression equation of extraction process was determined by the tool of regression analysis in the Excle. It was as follows:Y=0.069096—0.034319X1+ 0.000045X2+0.004729X3+0.068109X4+0.004138X12—0.000038 X32—0.009692X42. All the tested factors affected the yield significantly in the microwave-assisted extraction, with the order as microwave power> ratio of solvents and material >extracting times>microwave time. Predicting the regression model equation, and according to instrument parameters of the practical situation, the optimal process conditions for Microwave-assisted Extraction was as follows:microwave time at 1 min, microwave power at 700 W, ratio of solvents and material at 60:1, extracting times at 4. Through the verification test, the yield of the antiseptic compositions was 35.16±0.11%. The active ingredients of Mallus doumeri were proved to be flavone, polyphenolic, saponins and etc.by chemical qualitative determination.The antibacterial experiment in vitro showed that the antiseptic compositions from Mallus doumeri Leaf in March and June and September had inhibitory effect on Escherichia coli, Bacillus subtili, Proteus vulgaris, Staphyloclccus aureus, Aspergillus niger, Penicillium sp, Mucor racemosus, Hansenula anomala, Rhodotorula, Sacchar-omyces cerevisiae. Among them, the September of the antiseptic compositions had the most significant antibacterial activity. The minimum inhibition concentrations (MIC) were 2.50 mg/mL,5.00 mg/mL,5.00 mg/mL,2.50 mg/mL,5.00 mg/mL,10.00 mg/mL, 10.00 mg/mL, respectively. The half inhibiting time(IC5o) were 5.00 mg/mL,10.00 mg/mL,10.00 mg/mL,5.00 mg/mL,10.00 mg/mL,10.00 mg/mL,20.00 mg/mL, respectively.In the experiment of scavenging on free radical in vitro, the antiseptic compositions of Mallus doumeri Leaf in different seasons showed the scavenging effect on hydroxyl radical(·OH), superoxide anion radical (·OH) and DPPH, the scavenging order was DPPH>·OH>O2·. Among them, the September of Mallus doumeri Leaf natural antiseptic and preservative had the most significant scavenging effect. The half scavenging concentration(IC5o) were 1.62 mg/mL,3.45 mg/mL,4.13 mg/mL, respectively.The stability test of the antiseptic compositions from Mallus doumeri Leaf showed that it need to avoid light, and could keep better stability in acidic condition and in the temperature less than 60 degrees. The tolerance of the September of the antiseptic compositions was superior to March and June.The application test of the antiseptic compositions from Mallus doumeri Leaf showed that the antibacterial effect of it combined with the common chemical preservative(sodium benzoate, potassium sorbate) and vitamin C was much better than that of the antiseptic compositions from Mallus doumeri Leaf single use. The antiseptic compositions had significantly preservation effect on pork. Moreover, the oxidation rate of oil was decreased by the antiseptic compositions, and the effect of antioxidation on oil was increased along with the increasing of the test sample concentration. The antiseptic compositions from Mallus doumeri Leaf had synergistic action with VC, PG.In summary, Microwave-assisted Extraction had benefits to the extraction of the antiseptic compositions of Mallus doumeri Leaf, it was a high-efficient, fast and had protective effect to active compositions of Mallus doumeri Leaf. It would be applied to extraction of Mallus doumeri Leaf natural antiseptic and preservative and the active compositions of Mallus doumeri Leaf. Moreover, three seasons of the antiseptic compositions had the functions of bacteriostasis free radical scavenging, antioxidation on oil. It could be applied in food industry as a new type of natural preservative preservative, meanwhile, it could extend the food shelf life and reduce the addition of chemical synthesis The research would offer a new approach for the utilizational of Mallus doumeri Leaf.
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