Extration And Separation And Function Of Acorn Shell Polyphenols

Acorn shells are a rich resources by-product of acorn processing,contents abundant functional components such as polyphenols and have many functional activities.For the development and utilization of acorn shells,the Quercus acorn shells as raw material,the extraction method of acorn shell polyphenols were investigated by ultrasonic assisted solvent extraction and single factor test and orthogonal test,the acorn shell polyphenols were separated by solvent extraction method,the structure and component composition of acorn shell polyphenols was analyzed by chemical qualitative test,ultraviolet spectrum,infrared spectrum and high performance liquid chromatography,the functional activity of acorn shell polyphenols were also investigated by in vitro antioxidant and antibacterial test.The results show that:(1)The optimum extraction conditions of acorn shell polyphenol is that Acorn shells power which were crushed through 25 mesh sieve were extracted for 2 hour with 40% ethanol at 1:20 ratio of material to liquid under 60℃ by ultrasonic assisted extraction three time,the extraction rate of the acorn shell polyphenols was the highest to 4.39%.(2)Acorn shell polyphenols can be separated into F1,F2,F3 components by extracting with ethyl acetate and n-butanol.F1,F2,F3 was identified as polyphenols by chemical qualitative test.UV spectrum analysis showed that F1 have absorption peak in 190 nm and 274 nm,F2 have absorption peak in 198 nm and 273 nm,F3 have absorption peak in 213 nm and 273 nm,consistent with the UV absorption features of the polyphenols,acorn shell separation components was also identified as polyphenols by UV spectrum analysis.Infrared spectrum analysis showed that the absorption peaks of F1,F2 and F3 separation fractions is similar in other wavenumber except in the range of 2950-2900 cm-1,1300-1250 cm-1 and 850-800 cm-1,that prove to contain the structure of phenolic hydroxyl,carbonyl,C=C aromatic skeleton,C-H and C-O-C bond.(3)HPLC analysis showed that the component of F1,F2 and F3 have remarkable difference.F1 contains 4 kinds of phenols,the content of ellagic acid is the highest,the next is gallic acid,catechin,the content of protocatechuic acid is the lowest.F2 contains 11 kinds of phenolic,the content of ferulic acid is the highest,next were ellagic acid,gallic acid,catechin,epigallocatechin,epicatechin,chlorogenic acid,protocatechuic acid,caffeic acid,epicatechin gallate,the content of kaempferol is the lowest.F3 contains 4 kinds of phenolic,the content of ferulic acid is the highest,the gallic acid and ellagic acid is second,the content of quercetin is the lowest.All of F1,F2 and F3 separation fractions contains gallic acid and ellagic acid,but the content of gallic acid and ellagic acid in F1 is the highest,the F2 is second,the F3 is the lowest,this shows that the solubility of gallic acid and ellagic acid is the largest in ethyl acetate,the second in n-butanol,the smallest in water.(4)The vitro antioxidant experiment results showed that the DPPH radical scavenging rate of the crude extraction of acorn shells,separation fractions and control Vc is Vc > F3 > F2 > crude extractive > F1;ABTS radical scavenging rate is Vc > F2 > F3 > F1 > crude extractive,hydroxyl radical scavenging rate is Vc>F 3> crude extractive > F2 > F3,the total reducing capacity is Vc > crude extractive > F3 > F2 > F1.Under certain concentration range,the antioxidant capacity of the acorn shell extractive,three separation fractions exhibited good linear relationship enhancing with raising concentration.(5)The antimicrobial test results showed that the acorn shell crude extractive and F1,F2,F3 separation fractions have different degrees inhibition to Staphylococcus aureus,Listeria Lester bacteria,Escherichia coli and Salmonella,the antibacterial effect of the acorn shell crude extractive and F1,F2,F3 separation fractions is the best inhibition to Staphylococcus aureus and Listeria Lester,the worst inhibition to Escherichia coli and Salmonella.The antibacterial effect of F1 is the best to 4 kinds of bacteria,this prove the acorn shell polyphenols had broad bacteriostasis effect,the antibacterial effect to the gram positive bacteria is strong than gram negative bacteria.