ANTHOCYANIN CONTENT, ANTIBACTERIAL ACTIVITY AND ANTIOXIDANT CAPACITY OF PURPLE CORN COB EXTRACT VIA ULTRASONIC EXTRACTION
This research work was a study of anthocyanin extraction from purple waxy corn cob using acetone acidified by hydrochloric acid as an extracting solvent accompany with ultrasonic technique. The work was emphasized on the amount of anthocyanin extract and the evaluation of their antimicrobial activity and antioxidant capacity. The extract was analyzed by UV-VIS spectroscopy for its total anthocyanin content. The results showed that the total anthocyanins content was 7,869.26 μg CGE/g DW. The antibacterial activity test of the extract was performed and determined for their minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) in two species of bacteria namely Escherichia coli and Staphylococcus aureus. It was found that the MIC and MBC values of Escherichia coli were similar and they were equal to 25 mg/mL. Whereas the MIC value of 50 mg/mL and the MBC value greater than 200 mg/mL were found for Staphylococcus aureus. The antioxidant capacity of anthocyanin extract was tested with two methods namely DPPH assay and FRAP assay. It was revealed that anthocyanin extract exhibited antioxidant characteristic in both tests. Result from DPPH assay showed that antioxidant activity of anthocyanin extract was 1.5 and 4 times higher than vitamin C and vitamin E, respectively.
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