Chemical Composition of Essential Oils and Supercritical Carbon Dioxide Extracts from Amomum kravanh, Citrus hystrix and Piper nigrum ‘Kampot’

Abstract

The fruits of Amomum kravanh, Citrus hystrix and Piper nigrum ‘Kampot’ are traditionally used as spices in Cambodian cuisine. In this study, the chemical composition of essential oils (EOs) and supercritical CO2 extracts from all three species was determined using GC-MS, with two columns of different polarity (HP-5/DB-HeavyWAX). Differences between the chemical profile of the EOs and CO2 extracts were observed for all species. The greatest difference was detected in A. kravanh EO containing mainly eucalyptol (78.8/72.6%), while the CO2 extract was rich in fatty acids (13/55.92%) and long-chain alkanes (25.55/9.54%). Furthermore, the results for the CO2 extract of this species differed, where tricosane (14.74%) and oleic acid (29.26%) were the main compounds identified when utilizing the HP-5 or DB-HeavyWAX columns, respectively. Moreover, the EO and CO2 extract from P. nigrum ‘Kampot’ fruits and the CO2 extract from C. hystrix fruit peel, containing respective amounts 34.84/39.55% (for EO) and 54.21/55.86% (for CO2 extract) of β-caryophyllene and 30.2/28.9% of β-pinene, were isolated and analyzed for the first time. Generally, these findings suggest that supercritical CO2 could potentially be used for the extraction of all three spices. Nevertheless, further research determining the most efficient extraction parameters is required before its commercial application.