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

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 CO 2 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 CO 2 extracts were observed for all species. The greatest difference was detected in A. kravanh EO containing mainly eucalyptol (78.8/72.6%), while the CO 2 extract was rich in fatty acids (13/55.92%) and long-chain alkanes (25.55/9.54%). Furthermore, the results for the CO 2 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 CO 2 extract from P. nigrum 'Kampot' fruits and the CO 2 extract from C. hystrix fruit peel, containing respective amounts 34.84/39.55% (for EO) and 54.21/55.86% (for CO 2 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 CO 2 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.