OPTIMIZING ENZYMATIC EXTRACTION OF Zn-CHLOROPHYLL DERIVATIVES FROM PANDAN LEAF USING RESPONSE SURFACE METHODOLOGY

Abstract

ABSTRACT The objective of this research was to investigate the formation of Zn–chlorophyll complexes in the pandan leaf with the goal of producing a greener, more stable and natural chlorophyll colorant using enzymatic extraction to produce the highest yield of Zn–chlorophyll derivatives. The reaction of chlorophyll compounds in fresh pandan leaves with 300 ppm zinc chloride at pH 5 and 110C for 15 min produced the optimal conditions for Zn–chlorophyll complex formation. The commercial enzyme pectinase (Pectinex Ultra SP-L) assisted in the extraction process and an experimental design using response surface methodology was further optimized for the highest yield. The optimum conditions were 2.3–2.5% v/w pectinase, 240–260 min incubation time and extraction repeated twice at 35C. Under the optimum conditions, the extraction yields of green chlorophyll derivatives and antioxidant values were increased 17.31- and 1.92-fold, respectively, over untreated samples. PRACTICAL APPLICATIONS There is demand for natural colorant in the food industry and the green color from chlorophyll is highly desired. However, chlorophyll in natural sources is in the unsuitable form for use as a colorant because of its rapid degradation. Thus, the extraction procedure should start with formation of stable chlorophyll derivatives by creating a reaction using zinc chloride with the purpose of forming Zn–chlorophyll derivatives. This product has a more stable green color and has higher amounts of antioxidants. Subsequently, hydrolytic enzyme is used to extract the derivatives. The outcome has a natural green color with higher stability and is also safe because there are no solvents used during extraction which can bring about toxic residues. The process studied could be an alternative for the production of natural green colorant in the food industry.