ISSN 1715-7862 [PRINT] ISSN 1715-7870 [ONLINE] www.cscanada.net www.cscanada.org Advances in Natural Science Vol. 6, No. 4, 2013, pp. 84-95 DOI:10.3968/j.ans.1715787020130604.1638 84 Copyright © Canadian Research & Development Center of Sciences and Cultures Biological Signifcance of Spicy Essential Oils Sumitra Maurya [a] ; Ajeet Kumar Kushwaha [b] ; Gurdip Singh [c],* [a] PhD. Chemistry Department, Brahmanand PG College, Kanpur, India. [b] Research scholar. Chemistry Department, Brahmanand PG College, Kanpur, India. [c] Professor. PhD. Chemistry Department, DDU Gorakhpur University, Gorakhpur, India. * Corresponding author. Received 20 August 2013; accepted 5 November 2013 Abstract Spices are used as food additives since ancient times, as flavouring agents but also as natural food preservatives. Spice essential oils are complex mixtures of volatile substances, ordinarily terpenes, sesquiterpenes and oxygenated derivatives. They have been largely employed for their properties already observed in nature i.e., for their antibacterial, antifungal and insecticidal properties. At present, approximately 3000 essential oils are known, 300 of which are commercially important especially for pharmaceutical, agronomic, food, sainitary, cosmetic and perfume industries. It is important to develop a better understanding of their mode of action for new applications in human health, agriculture and environment. Some of them constitute effective alternatives or complements to synthetic compounds of chemical industry. Key words: Spice essential oil; Antibacterial; Antifungal; Insecticidal; Food additives Sumitra Maurya, Ajeet Kumar Kushwaha, Gurdip Singh (2013). Biological Significance of Spicy Essential Oils. Advances in Natural Science, 6 (4), 84-95. Available from: http://www.cscanada. net/index.php/ans/article/view/j.ans.1715787020130604.1638 DOI: http://dx.doi.org/10.3968/j.ans.1715787020130604.1638 INTRODUCTION Spices, which are important part of human diets, have been used for thousands of years to enhance the flavour, colour and aroma of food. In addition to boosting flavour, herbs and spices are also known for their preservative (Neilsen & Rios, 2000), antioxidative (Shobana & Naidu, 2000), antimicrobial and various other medicinal values (Wood et al., 2001), which forms one of the oldest sciences. Scientific experiments since 19 th century have documented the antioxidative and antimicrobial properties of spices and their components. Essential oils of spices are volatile, natural complex compounds, characterized by a strong odour and are found in aromatic plant as secondary metabolites for which aromatic plants are used in the pharmaceutical, food and fragrance industries. They comprise as several hundred constituents, especially hydrocarbon (terpenes and sesquiterpenes) and oxygenated compound (aldehydes, ketones, alcohols, acids, phenols, oxides, lactones, acetate, ethers and esters) (Anitescu et al., 1997). The extraction of essential oil components using solvents at high pressure, or supercritical fluids, has received much attention in the past several years, especially in food, pharmaceutical and cosmetic industries, because it presents an alternative to conventional processes such as organic extraction and steam distillation (Eikani et al., 1999). The extraction product can vary in quality, quantity and in composition according to climate, soil composition, plant organ, age and vegetative cycle stage (Masotti et al., 2003; Angioni et al., 2006). A lot of data of spice essential oils are reported in the literature but they are not systematical and concise. Therefore, this review is written in keeping in view to provide a better understanding of methods of extraction of spices essential oils and their mode of biological action for new applications in human health, agriculture and environment. Some of them constitute effective alternatives or complements to synthetic compounds of chemical industry.