The solvent-free microwave extraction of essential oil from ginger was optimized using a 23 full factorial design in terms of oil yield to determine the optimum extraction conditions. Sixteen experiments were carried out with three varying parameters, extraction time, microwave power, and type of sample for two levels of each. A first order regression equation best fits the experimental data. The predicted values calculated by the regression model were in good agreement with the experimental values. The results showed that the extraction time is the most prominent factor followed by microwave power level and sample type for extraction process. An average of 0.25% of ginger oil can be extracted using current setup. The optimum conditions for the ginger oil extraction using SFME were the extraction time 30 minutes, microwave power level 640 watts, and sample type, crushed sample. Solvent-free microwave extraction proves a green and promising technique for essential oil extraction. 1. Introduction The principal aim of green chemistry and engineering is to reduce chemical related impact on human health and to search alternative, environmentally friendly and energy efficient production methods. Green and clean extraction methods can offer more natural products, free from toxic solvents. The search for such green extraction methods is highly emphasized in essential oils industries since last decade because of consumer’s preference towards natural products. Essential oils are volatile extract of the spices, medicinal and aromatic plants. The history of essential oil extraction and their use for various purposes is very old. Zingiber officinale Roscoe, commonly known as ginger, is a member of Zingiberaceae family. Most Zingiberaceae family spices are fibrous rooted perennial herb which is cultivated in many tropical and subtropical areas, India, North East Asia, Australia, and Japan. The use of ginger as spice and medicine is very old and is mentioned in earliest Chinese and Sanskrit literature [1]. Ginger species possesses aromatic properties and has a commercial importance. There are two valuable extracts of ginger, essential oil which varies as 0.8–4.2% and oleoresin in the range of about 7% depending on its origin habitat and agronomic treatment of culture [2]. Ginger oil possesses the natural aroma of crude ginger and is globally used in flavour, perfumer, and pharmaceutical and liqueur industry [3]. The therapeutic properties of ginger oil are antiseptic, antispasmodic, carminative, cephalic, expectorant, febrifuge, laxative, and stomachic [4, 5]. The
References
[1]
B. N. Korla and N. P. Dohroo, “Production technology in ginger—a review,” Agricultural Reviews, vol. 12, no. 1, pp. 22–36, 1991.
[2]
M. Noor Azian, M. S. Sazalina, and M. R. Haira Rizan, Essential Oil and Active Ingredients Extraction from Ginger Plants, Annual Progress Report Centre of Lipids Engineering & Applied Research, Kuala Lumpur, Malaysia, 2001.
[3]
E. Langner, S. Greifenberg, and J. Gruenwald, “Ginger: history and use,” Advances in Therapy, vol. 15, no. 1, pp. 25–44, 1998.
[4]
Y. Hori, T. Miura, Y. Hirai et al., “Pharmacognostic studies on ginger and related drugs—part 1: five sulfonated compounds from Zingiberis rhizome (Shokyo),” Phytochemistry, vol. 62, no. 4, pp. 613–617, 2003.
[5]
B. H. Ali, G. Blunden, M. O. Tanira, and A. Nemmar, “Some phytochemical, pharmacological and toxicological properties of ginger (Zingiber officinale Roscoe): a review of recent research,” Food and Chemical Toxicology, vol. 46, no. 2, pp. 409–420, 2008.
[6]
Y. Yonei, H. Ohinata, R. Yoshida, Y. Shimizu, and C. Yokoyama, “Extraction of ginger flavor with liquid or supercritical carbon dioxide,” The Journal of Supercritical Fluids, vol. 8, no. 2, pp. 156–161, 1995.
[7]
M. J. Alfaro, J. M. R. Bélanger, F. C. Padilla, and J. R. J. Paré, “Influence of solvent, matrix dielectric properties, and applied power on the liquid-phase microwave-assisted processes (MAP？) extraction of ginger (Zingiber officinale),” Food Research International, vol. 36, no. 5, pp. 499–504, 2003.
[8]
J. R. J. Pare, “Microwave assisted process for extraction and apparatus therefore,” Canadian patent, CA 2055390, 1992.
[9]
M. E. Lucchesi, J. Smadja, S. Bradshaw, W. Louw, and F. Chemat, “Solvent free microwave extraction of Elletaria cardamomum L.: a multivariate study of a new technique for the extraction of essential oil,” Journal of Food Engineering, vol. 79, no. 3, pp. 1079–1086, 2007.
[10]
M. A. Ferhat, B. Y. Meklati, F. Visinoni, M. A. Vian, and F. Chemat, “Solvent free microwave extraction of essential oils: green chemistry in the teaching laboratory,” Chemistry Today, vol. 26, no. 2, pp. 48–50, 2008.
[11]
M. E. Lucchesi, F. Chemat, and S. Jacqueline, “Solvent free microwave extraction: an innovative tool for rapid extraction of essential oil from aromatic herbs and spices,” Journal of Microwave Power and Electromagnetic Energy, vol. 39, no. 3-4, pp. 137–140, 2004.
[12]
X. Chen, Y. Zhang, Y.-G. Zu, X.-Y. Yu, and J.-L. Li, “Optimization of solvent-free microwave extraction of essential oil from the fruits of Schisandra chinensis and its DPPH radical scavenging activity,” Food Science, vol. 32, no. 14, pp. 85–89, 2011.
[13]
M. N. Azian, A. A. M. Kamal, and M. N. Azlina, “Changes of cell structure in ginger during processing,” Journal of Food Engineering, vol. 62, no. 4, pp. 359–364, 2004.
[14]
S. S. Chen and M. Spiro, “Study of microwave extraction of essential oil constituents from plant materials,” Journal of Microwave Power and Electromagnetic Energy, vol. 29, no. 4, pp. 231–241, 1994.
[15]
D. C. Montgomery and C. R. George, Applied Statistics and Probability for Engineers, John Wiley & Sons, Singapore, 3rd edition, 2003.
[16]
G. Derringer and R. Suich, “Simultaneous optimization of several response variables,” Journal of Quality Technology, vol. 12, no. 4, pp. 214–219, 1980.
