Optimization of essential oil extraction process of white pepper (Piper nigrum L.) harvested in Phu Quoc Island, Kien Giang Province, Vietnam

Abstract

Vietnam is a leading producer and exporter of products harvested from plants of the family Piperaceae such as green pepper, black pepper, red pepper and white pepper. In this study, an attempt is made to examine the essential oil extraction process with the material of white pepper grown and harvested in Phu Quoc island, Vietnam. To maximize essential oil production, three factors consisting the ratio of materials and solvents, extraction time and extraction temperature were selected and optimized. The surface response methodology optimization resulted the highest yield of 3.6%, achieved at the ratio of material and water ratio of 1:20 g/g, extraction time of 96 min and at 130 ºC. A high F values, low P values (< 0.0001), the determination coefficient (R2 = 0.9993) and a non-significant lack of fit suggested a strong correlation between actual and predicted values of the responses. The essential oil obtained was determined for chemical composition by gas chromatography-mass spectrometry (GC-MS) method. The GC-MS results showed that major constituents existing in the oil sample were limonene, 3-carene, sabinene, β-pinene, α-pinene and α-phellandrene, accounting for 27.059, 23.345, 17.903, 9.996, 5.167 and 4.588%, respectively.