Composition And Biological Activity Analysis Of Polyphenols In Walnut Valve

Diaphragma juglandis is a wooden diaphragm between walnut nuts,and it contains various active ingredients such as phenolic acid,brass,and saponin.Traditional Chinese medicine believes that it has the effect of tonifying kidney and astringent essence,but it is often abandoned in daily life.In this paper,the composition and physiological functions of polyphenols in diaphragma juglandis and their preservation effects on mutton and goat milk were investigated to provide a theoretical basis for the development and application of diaphragma juglandis.The main exprement results are presented in the follows:(1)The composition of polyphenols in diaphragma juglandis was analyzed and the anti-oxidation and antibacterial effects of diaphragma juglandis polyphenols at different concentrations were determined.Optimum extraction concentration of ethanol on diaphragma juglandis polyphenols was screened,and its compositions were analyzed by HPLC.The reducing capacity of diaphragma juglandis polyphenols on potassium ferricyanide,the scavenging capacity on DPPH radical and hydroxyl radical were detenrmined.The inhibitory effects of different concentrations of diaphragma juglandis polyphenols on Escherichia coli(Gram-negative bacteria)and Staphylococcus aureus aureus(Gram-positive bacteria)were determined by oxford cup,microbial growth curve and laser scanning confocal microscopy.The compositions of diaphragma juglandis polyphenols were analyzed.The results showed that the extraction rate of diaphragma juglandis polyphenols with 60%ethanol.The main components of diaphragma.juglandis polyphenols were gallic acid,protocatechuic acid,chlorogenic acid,catechin,rutin ellagic acid,and mass fractions were 1.66,0.97,3.01,9.72,0.68 and 0.93%respectively.The anti-oxidation effects of different concentrations of diaphragma juglandis polyphenols were analyzed.The reduction capacity on potassium ferricyanide and the DPPH radicals and hydroxyl radicals scavenging capacity of diaphragma juglandis polyphenols were strong.The reducing capacity on potassium ferricyanide and the scavenging capacity on DPPH radical all increased with increasing polyphenols concentration(P<0.05).When the polyphenol concentration reached 0.26 mg/mL,the scavenging rate of hydroxyl radical increased significantly with increasing concentration(P<0.05).The inhibitory effects of different concentrations of diaphrag,ma juglandis polyphenols on Escherichia coli and Staphylococcus aureus were analyzed.When the concentration of polyphenols in diaphragma juglandis was 0.26 mg/mL and 0.52 mg/mL,there was no significant difference in the size of inhibition zone(P>0.05),and there was a significant difference in the size of inhibition zone when the concentration of polyphenols was 0.17 mg/mL compared with that of high concentration treatment(P<0.05).The minimum inhibitory concentration of walnut valve polyphenols to E.scherichia coli and Staphylococcus aureus was 59.0 ?g/mL.At 7.8 and 15.5 pg/mL,the growth trend of Escherichia coli was not significantly different from that of blank control,but when the concentration was 30.5 ?g/mL,the optical density were lower than those of the control.The results showed that diaphragma juglandis polyphenols had certain inhibitory effect on Escherichia coli at this concentration.When the concentration of polyphenol reached 59.0 ?g/mL,the OD value did not change significantly,that is,there was no significant growth of Escherichia coli.Staphylococcus aureus were inhibited when the concentration of polyphenols in diaphragma juglandis was greater than 7.8 pg/mL,and they did not grow significantly when the concentration was higher than 59.0 ?g/mL.Escherichia coli and Staphylococcus aureus were treated with diaphragma juglandis polyphenols at concentrations of 30.5 ?g/mL and 59 ?g/mL,respectively.Polyphenols of high concentration has strong inhibitory effect on microorganisms.The extraction rate of polyphenols in diaphragma juglandis by 60%ethanol was the highest.The main component of diaphragma juglandis polyphenols were gallic acid,protocatechuic acid,chlorogenic acid,catechin,rutin ellagic acid,which had significant antioxidant activity and had certain inhibitory effects on Escherichia coli and Staphylococcus aureus.(2)The preservation effect of different concentrations of diaphragma juglandis polyphenols on mutton and goat milk were studied.The colony number,the concentration of ammonia nitrogen compounds,volatile base nitrogen,aflatoxin and ATP on mutton and goat milk,and color value of mutton before and after treatment with different concentrations of diaphragma juglandis polyphenols were determined.The results of preservation on mutton showed that the colony number,ammonia nitrogen compounds,volatile base nitrogen and ATP contents on mutton decreased significantly with the increase of the concentration of diaphragma juglandis polyphenols(P<0.05).The inhibitory effect on volatile base nitrogen was not significant when the concentration of polyphenols was more than 0.17 mg/mL(P>0.05).The inhibitory effect on aflatoxin of mutton was not significant at low concentration of polyphenols(P>0.05),and the aflatoxin content decreased significantly with the increase of the concentration polyphenols when the concentration reached 0.26 mg/mL(P<0.05).The redness value(a*)and brightness value(L*)of mutton increased significantly with the increase of the concentration of diaphragma juglandis polyphenols(P<0.05).The results of preservation on goat milk showed that the colony number on goat milk decreased significantly compared with untreated group(P<0.05)when the concentration of diaphragma juglandis polyphenols reached 0.17 mg/mL,but there was no concentration-dependent relationship,that is,when the concentration of diaphragma juglandis polyphenols was more than 0.17 mg/mL,the growth and reproduction of microorganisms on goat milk could be inhibited.The concentration of ammonia nitrogen compounds and volatile base nitrogen on goat milk decreased significantly with the increase of diaphragma juglandis polyphenols concentration(P<0.05),and the inhibition reached the maximum when the concentration of polyphenols reached 0.17 mg/mL and 0.26 mg/mL respectively.The conent of ATP on goat milk was significantly lower than other concentrations when the polyphenols concentration was 0.52 mg/mL(P<0.05).Diaphragma juglandis polyphenols had significant effects on preservation of mutton and goat milk,and had good protective effect on meat color.