DERIVATIZATION OF CHLOROPHYLL FROM PANDAN (Pandanus amaryllifolius Roxb.) LEAVES AND THEIR ANTIOXIDANT ACTIVITY

Chlorophyll is a natural coloring agent that has antioxidant activity. During the extraction and food processing process, chlorophyll is easily degraded and derivatized. The derivatization process results in changes in the chemical structure of chlorophyll which can result in a change in color and its antioxidant activity. The other extracted minor compounds can affect its antioxidant activity. This study aimed to identify the chemical structure changes of chlorophyll extracted from pandan (Pandanus amaryllifolius Roxb) leaves as affected by the derivatization process and evaluate the antioxidant activity of the extracts and fractions of chlorophyll and its derivatives. Chlorophyll was extracted from pandan leaves with acetone, derivatized, and then purified by fractionation using column chromatography. Chlorophyll extract and its derivatives were analyzed for total carotenoid, total phenolic, and flavonoid contents. The antioxidant activity of extract and fraction was measured by the inhibition of peroxidation of linoleic acid, radical scavenging activity of 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing/ antioxidant power (FRAP) ability, and metal chelating assay. Based on the FTIR and MS/MS spectra, it was observed that the first derivatives were pheophytin and chlorophyllide, while the second derivative was pheophorbide. The other extracted compounds, including phenolic compounds, flavonoids, and carotenoids, might enhance the antioxidant activity of the chlorophyll derivatives. The inhibition rate of linoleic acid peroxidation by chlorophyll, chlorophyllide, and pheophorbide extract was not significantly different from BHT, where pheophytin extract was lower. The radical scavenging activity of DPPH and FRAP assay showed that chlorophyll and chlorophyllide extracts exhibited higher activity, followed by pheophytin and pheophorbide. Meanwhile, the metal chelating assay showed that chlorophyllide fraction exhibited the lowest activity. Therefore, the antioxidant activity of the first derivatives of chlorophyll was higher than the second derivatives. In general, the extract of chlorophyll and its derivatives exhibited higher antioxidant activity than that of their fraction.