Effect of enzyme pre-treatment on extraction yield and quality of cardamom (Elettaria cardamomum maton.) volatile oil

Abstract

The effect of enzyme pretreatment on extraction yield and quality of volatile oil of cardamom seeds were evaluated using various enzymes viz., Celluclast 1.5L, Pectinex Ultra SP.L, ViscozymeL and Protease. Scanning Electron Microscopic (SEM) studies were conducted to visualize the effect of these enzymes on cardamom seed cell walls. The quality of the oil was further evaluated using Gas Chromatography Mass spectroscopy (GC–MS). The enzyme pretreatment resulted in an increase in yield of oil in the range of 7.23–7.83% as against 6.73% of the control sample. The enzyme pretreatment with ViscozymeL was proved to be most effective than all other tested samples. Scanning electron microscopic analysis of cardamom seeds revealed that the cell rupture in enzyme treated seeds are smooth and open due to the hydrolysis of cell wall compounds, whereas water treatment resulted only in structural damage. It was further observed that enzyme pretreatment facilitated the release of oil from oil glands without affecting the physico-chemical properties or flavor profile of the oil. GC–MS studies indicated that the flavor profile of cardamom oil contains the major flavor compounds viz., 1, 8 cineol and terpinyl acetate increased from 34.3 to 37.6% and 40.8–42.3% respectively with enzyme pre-treatment. In economic point of view, the results of the present study could be used effectively in spice industry to increase the extraction yield and quality of volatile oil from cardamom seeds.