Construction,Mechanism And Application Research Of Natural Preservative System

In recent years,consumers’demand for cosmetics has mostly focused on functionality and safety.Preservatives in cosmetics are essential parts of product protection.They are also the main sources of irritation in cosmetics.Therefore,the development of an efficient,mild and natural preservative system is a hot topic in the development of cosmetic raw materials.In this study,antimicrobial plants from different natural sources were extracted and compounded to obtain natural antimicrobial compounds with high efficacy and broad spectrum.The antimicrobial mechanism,safety,and preservative properties of the compounds were studied.Four Chinese herbal medicine plants,Syzygium aromaticum,Coptis chinensis,Houpoea officinalis and Punica granatum,with antimicrobial efficacy and a wide range of sources were extracted by different solvents.The most effective for each test microbial was selected by determining the inhibition zone of Staphylococcus aureus,Escherichia coli,Pseudomonas aeruginosa,Candida albicans and Aspergillus brasiliensis.Extracts with high inhibitory effect:clove alcohol extract,coptis water extract and pomegranate alcohol extract were selected.A natural antimicrobial compound with high efficacy and broad-spectrum antimicrobial were constructed through the orthogonal table L₁₆（4³）.In this natural antimicrobial compound,the volume ratio of clove,coptis and pomegranate peel is 4:4:1,and the diameters of inhibition zones of S.aureus,E.coli,P.aeruginosa,C.albicans and A.brasiliensis are（25.50±0.56）mm,（19.00±0.57）mm,（16.30±0.41）mm,（27.95±0.35）mm,（31.93±1.12）mm,and the minimum inhibitory concentrations（MIC）are:0.49 mg/m L,3.91 mg/m L,3.91 mg/m L,1.95 mg/m L,3.91 mg/m L.The antimicrobial components of clove extract,coptis extract and pomegranate extract were analyzed by high performance liquid chromatography,and the main antimicrobial components were determined to be eugenol,berberine and punicalagin.Then,by analyzing the microbial growth curves,cell membrane permeability and intracellular protein leakage of each single component and compound affecting on Staphylococcus aureus,Escherichia coli,Pseudomonas aeruginosa and Candida albicans,it was shown that plant extracts achieve antimicrobial effects by disrupting the microbial growth cycle and affecting cell structure.The irritation and preservative efficacy of the natural antimicrobial compound were studied.The irritation test（HET-CAM assay）showed that the natural antimicrobial compound has no irritation at the tested concentration,and is milder than traditional preservatives.The natural antimicrobial compound was applied to skin toner,lotion and cream.Preservative challenge test results showed that the addition of 1%or more of the compound could meet the preservative requirements of different formulation.