Yunnan Ten Kinds Of Chili Antioxidant And Antibacterial Activity

In this paper, the main function ingredients of ten peppers of Yunnan were determined and antioxidant and antimicrobial activities were evaluated.The contents of total capsaicins, total carotenoids, vitamin C and total polyphenols were assayed. The results showed that the functional components of red peppers were generally higher than green peppers. The highest content of Vc (3.930mg·g-1) and carotenoids (1414.78μg·g-1) were in long red chilli fruit.The highest content of total capsaicins (1380.977μg·g-1) and total polyphenols (4992.391μg·g-1) were obtained from Capsicum frutescens L fruit.The component and content of flavonoids and phenolic compounds in extracts of peppers were determined by HPLC. Gallic acid, protocatechuic acid, caffeotannic acid, vanillin, capsaicin, dihydrocapsaicin, quercetin and luteolin could be found in the ten different peppers of Yunnan. The highest total content of capsaicins and phenolic acids were found in Capsicum frutescens L fruit. The long red chilli had the highest content of benzoic acid, vanillin and quercetin, which were 176.763μg·g-1, 3.26μg·g-1 and 3.26μg·g-1, respectively. The wrinkled pepper had the highest content of gallic acid, which was 16.124μg·g-1. The capsicum frutescens L had the highest content of protocatechuic acid, caffeotannic acid, campherol, rutin, luteolin and capsaicins, which were 31.393μg·g-1,73.618μg·g-1,2.196μg·g-1,73.015μg·g-1, 0.844μg·g-1 and 1380.977μg·g-1, respectively. The red chilli had the highest content of salylic acid, which was 70.611μg·g-1.Antioxidant activities of pepper extract were comprehensive evaluated by using DPPH radical scavenging activities, reducing power, hydroxide radical scavenging abilities and liposome peroxidation inhibiting test. Capsicum frutescens L had the strongest antioxidant capability on scavenging DPPH radical and inhibiting liposome peroxidation activities, and the IC50 were 0.834mg.mL-I and 3.0mg·mL-1 respectively. Long red chilli had the strongest antioxidant capability on reducing power and scavenging hydroxide radical activity, and the IC50 of hydroxide radical scavenging activity was 3.577mg·mL-1. The antioxidant capability of red peppers was generally higher than green peppers. Capsicum frutescens L. and long red chilli had good antioxidant activities compared to that of Vc.Results showed the antimicrobial activities of the pepper extracts against fungi were weak because of the different strains of microbes. The extract of capsicum frutescens L had the best antibacterial activity on Staphylococcus aureus, whose minimum inhibit concentration was 1.75mg·mL-1.The minimum inhibit concentrations of the extract of capsicum frutescens L on Bacillus coli and Bacillus subtilis were 3.5mg·mL-1 and 3.5mg·mL-1, respectively. Extracts of green peppers had no antimicrobial activities on Penicillium, Aspergillus and far lower antibacterial activity on Staphylococcus aureus, Bacillus coli and Bacillus subtilis than those of red peppers.The MIC of the screw pepper extract on Staphylococcus aureus, Bacillus coli and Bacillus subtilis were 7.0mg·mL-1,7.0mg·mL-1,14.0mg·mL-1.