| Diospyros lotus,belonging to the genus Diospyros,is abundant in the Yellow River Valley in China.Diospyros lotws is not only rich in nutrients,but also has therapeutic functions such as lowering blood pressure,blood lipids,and anti-oxidation.In this paper,the Diospyros lotus from Shexian County,Hebei Province was selected as raw material to study the extraction process,chemical composition,antioxidative activity,antibacterial activity and cytotoxicity of Diospyros lotus essentia]oil.The purpose was to improve the processing technology of Diospyros lotus essential oil and promote the development of industrial structure of the Diospyros lotus in the Yellow River Basin,Provide theoretical reference for the efficacy and safety of Diospyros lotus essential oil.In this paper,the organic solvent method and supercritical CO2 extraction method were used to extract Diospyros lotus essential oil,and the optimun extraction process was optimized and compared.The chemical composition of Diospyros lotus essential oil was detected by the liquid quality method;three methods were used(clear DPPH free radical method,The antioxidant activity of Diospyros lotus essential oil was determined by scavenging Hydroxyl radical method and P·carotene linoleic acid system inhibition method).The agar disk diffusion method and minimal inhibitory concentration method were used to evaluate the ability of Diospyros lotus oil to inhibit microorganisms.The cell membrane integrity test was used to explore the antibacterial mechanism;MTT staining method was used to determine the cytotoxicity of Diospyros lotus oil,and the safety of Diospyros lotos oil was evaluated.The results showed that:the organic solvent extraction method of Diospyros lotus essential oil,orthogonal test method to optimize the process flow:the extraction agent is petroleum ether,the length of 4 h,the temperature is 50?,the ratio of material to liquid 1:20,the extraction rate is 5.10±0.12%;supercritical carbon dioxide extraction extraction of Diospyros ltus essential oil,the response surface experiment after optimization of the process:pressure of 25 MPa,temperature of 52.4oC,time of 2.12 h,extraction rate of 5.91±0.04%.The yield of Diospyros lotus essential oil extracted by supercritical extraction method was slightly higher than that of organic solvent extraction method,indicating that supercritical fluid extraction method is more conducive to the enrichment of the active components of Diospyros lotus essential oil.The composition of Diospyros lotus essential oil extracted by supercritical carbon dioxide was studied using GC-MS analysis:aldehydes 55.20%,alcohols 25.84%,ketones 6.73%,esters 5.76%,acids 5.27%,alkanes 0.34%.The DPPH radical scavenging method,scavenging Hydroxyl radical method,and ?-carotene Iinoleic acid system inhibition method were used to detenmine the antioxidant capacity of Diospyros lotus oil,and the IC50 value of Diospyros lotus oil to DPPH clearance was 46.27±1.70?g/mL.The IC50 value for the scavenging of hydroxyl radicals was 0.56±0.03 mg/mL,and the IC50 value for inhibition of?-carotene linoleic acid system was 0.96±0.01 mg/mL,Diospyroslorus essential oil has moderate antioxidant activity.The antibacterial experiment of Diospyros lotus showed that the diameters of the zone of inhibition of Escherichia coli,Staphylococcus aureus,Bacillus subtilis,Penicillium and Aspergillus liger were 12,11,10,13 and 12 mm,respectively;Escherichia coli,Staphylococcus aureus The minimum inhibitory concentrations of Bacillus sublilis,Penicillium and Aspergillus niger were 0.8,0.5,0.5,1.0,and 1.0 mg/mL,respectively.Diospyros lotus oil had moderate antibacterial activity against bacteria and fungi.The cell membrane integrity test showed that the antibacterial mechanism of Diospyros lotus essential oil may be achieved by destroying the bacterial cell membrane system and changing the cell membrane permeability to overflow the contents.Cytotoxicity experiments showed that the concentration of Diospyros lotus essential oil does not exceed 100 ?g/mL and may not affect cell survival. |
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