Study On The Cotent, Change And Antimicrobial Effect Of Capsaicin In Pepper Fruit

The capsaicin content of pepper fruit is an important quality index.For understanding the capsaicin content,change of capsaicin content with fruit development,and antimicrobial effect of capsaicin extracts about different pepper germplasm,supplying service to pepper breeding,harvesting,and processing,the 4 types of pepper were employed as materials,those materials are line pepper(T-dan 202,Shanjiao 2001,Shanjiao 2003,Shanjiao 2006,and Qicunhong),color pepper(Shancaijiao No.1 and Shancaijiao No.2),small hot pepper ((6Ge75)G4,(6Ge76)G5),and horn pepper(6Beo7,6Beo2,6Qf038,6Qf036,and Xiangyan No.13).By means of HPLC etc,the capsaicin content of different materials and different parts in pepper fruit,the change of PAL,POD,and CS activity in pericarp and placenta during fruit development,the change of vitamin C content during fruit development,the change of free phenol and soluble protein content in pericarp and placenta during fruit development,and the antimicrobial effect of capsaicin extracts were determined in this experiment.The results are as follows:1.The separating degree is more than 1.5 when proportion of methanol:0.1%phosphoric acid aqueous solution is 65:35.The capsaicin RT=10.533,and dihydrocapsaicin RT=15.873. The regression equation of capsaicin is f(x)=0.000171793^*x+5.35616,and R=0.9995.The regression equation of dihydrocapsaicin is f(x)=0.000171793^*x+5.35616,and R=0.9995.A good linearity of capsaicin(dihydrocapsaicin) was in the rang of 0.1236(0.0759)-4.9440 (3.0384)μg.The average reclaim rate of capsaicin and dihydrocapsaicin was 100.735%and 100.785%.The RSD was 1.79%.The experiment results showed that the equipment and method for HPLC is credible.2.About the content of capsaicin,the sequence of tested breeds ranged from high to low was small hot pepper,line pepper,horn pepper,and color pepper.The capsaicin content in small hot pepper fruit was 5211.7μg·g^-1·DW.The capsaicin content in line pepper,horn pepper, and color pepper is 1294.18,739.7,and 264.5μg·g^-1·DW respectively.3.The capsaicin content of different parts of pepper fruit in(6Ge76)G5,Shanjiao 2006, 6Beo76,and Qf036 was determined.The results showed that the sequence from high to low was placenta,pericarp,and seed.4.The dynamic change of capsaicin content in Shanjiao 2006 pepper fruit was determined by means of HPLC.The results showed that the capsaicin content in pepper pericarp and placenta increased gradually with the development of fruit,but the content dropped a little in late days.From the 15^th to 30^th day after flowering,free phenolic content increased.From the 30^th to 40^th day after flowering,capsaicin content increased rapidly,while free phenolic content decreased greatly.In the last days of fruit development,capsaicin content fell slightly,however free phenolic content increased a little.The change of capsaicin content had a negative relationship with the content of free phenolic during metaphase and late stages of pepper fruit development.The contents of soluble protein and vitamin C increased gradually during pepper fruit development,and reached peak after 50^th day after flowering,and then fell a little.The change of Pr content showed a positive relationship with the content of capsaicin.The PAL activity in pepper fruit remained nearly constant from the 15^th to 25^th.Then the activity improved rapidly from 25^th to 40^th day and a major peak of activity was observed at 40^th day after flowering.After 40^th day,the PAL activity decreased. The CS activity remained a low level during the 15d after flowering,and a slight increase was detected from 15^th to 20^th day after flowering,followed by a sharp increase to attain a maximum at day 35^th after flowering,then a decrease in the CS activity was observed after 35^th day after flowering.Comparing the changes of capsaicin contents,there was an intimate relation between the content of capsaicin and activities of PAL and CS.POD activity was high in the early stage,and decreased gradually with the fruit development,and then increased in the final stage.According to the change of capsaicin content,it could be concluded that POD may be involved in capsaicin degradation.5.The experiment showed that the water extract of capsaicin had strongly antibacterial effect on Staphylococcus aureus and Escherichia coli in the content ranging from 118.3 to 1183μg·mL^-1,and had strongly inhibitory activities to Saccharomyces cerevisiae and Staphylococcus ellipoideus in the content above 354.9μg·mL^-1.The water extract of capsaicin had antifungal activites toward Aspergillus S P and Penicillium S P in the content above 828.1μg·mL^-1.