Characterization And Preparation Of Antibacterial Peptide From Perilla Seed Protein

Perilla meal is an industrial by-product after pressed perilla oil，its proteincontent is up to39.06%（dry basis），degreased in the actual production of perilla seedmeal is often uesd as animal feed or discarded directlu，causing environmentalpollution and waste of resources，in order to improve the economic value of Perillameal，the waste of resourced directly，causing environmental pollution and waste ofresoures，in order to improve the economic value of Perilla meal，the meal as the rawmaterial，the preparation of perilla seed protein isolate and perilla antibacterialpeptide，the test result are as follows：1.Perilla meal as raw materials，respectively by alkali extraction and acid precipitationmethod and Osborne preparation of protein isolates （PPI）and albumin（PAP），immunoglobulin（PGP），Glutenin（PLP）.The preparation conditions of Perilla proteinIsolate optimum process was determined by single facter and orthogonal experiments：acid precitation pH4.4，solid to liquid ratio of1﹕18，alkali extractionand pH10.0，alkali extraction temperature60℃，alkali extraction time60min，perillaseed protein isolate was34.5%under the optimum conditions，the purity of the proteinwas86.9%.According to the method of Osborne albumin（PAP）,immunoglobulin（PGP）and protein （PLP）mass fraction of60.1%,82.9%and74.7%respectively.2.Comparative analysis of precipitation from protein prepared by alkali solution andacid （PPI）prepared by Osborne and ablumin （PAP），immunoglobulin（PGP）and protein （PLP）functional properties.The results showed that four kinds of proteinpreparation of essential amino acids content could meet the recommended adultstandards FAO/WTO. PGP exposed sulfdryl content of up to27.3μmol/g，PLP twodisulfide bond content of up to20.38μmol/g；SDS-PAGE results showed that theisolated protein contains3other proteins of bands，mainly subunit molecular mass of10.5，20.1，32.7and40.6Ku；4protein solubility curve approximately is U shape，expect PGP in PGP in pH5，the other3proteins in pH4.0solubility minimum，allproteins solubility were highest in pH12.Foaming properitse near the isoelectricpoint of smaller，emulsification and emulsion stability increasing with the pH did notchange significantly;PAP water and oil holding relative maximum respectively3.81，3.93mL/g.3.Perilla separate protein as a raw material，the alkaline protease（Alcalase）wasprepared by hydrolysis of Perilla antibacterial peptide，the optimal process:6.89%of the amount of enzyme，hydrolysis temperature52.68℃，substrate concentration4.17%，pH8.98，3h hydrolysis conditions，prediction theory ofenzymatic hydrolysateof RSM value was19.33mm，the actual measured value is19.40mm.Antibacterialtests showed that perilla inhibitory effect of antibacterial peptide on Salmonella，bacillus and Staphylococcus aureus were.Heating and freezing thawing test show thatPerilla antibacterial peptide with the heating time and the increase in the number offreeze-thaw cycle inhibitory effect did not sigificantly decrease，good thermal stability.The degree of hydrolysis and bacteriostatic experiment showed that antibacterialactivityincreased with the degree of hydrolysis increased,then tends to be stable.