Essential oils are secondary metabolites produced by plants for protection against diseases and herbivorous insects.
Essential oils are a mixture of numerous compounds, mainly terpenes, alcohols, acids, esters, epoxides, aldehydes, ketones, amines and sulfides, that are probably produced by plants as a response to stress. Essential oils are extracted from flowers, leaves, fruits, fruit rinds seeds, stems, roots, barks, or resins of various plants.
Over the course of time, and with the benefit of many thousands of species of plants from which to produce them, countless numbers of such flavors and fragrances have found their way via essential oils onto everyday life: into foods and drinks and confectionery items, into products for personal use such as perfumes, deodorants, shampoos, bath lotions, toilets soaps, toothpastes and mouthwashes for example.
Essential oils are the highly concentrated, volatile, aromatic essences of plants. These natural plant oils are appreciated for both their aromatic and flavoring qualities.
Essential oils have been used in foods as flavoring, as well as preserving agents, due to antimicrobial and antioxidant properties. Their main active components are: thymol, carvacrol, eugenol, cinnamaldehyde and linalool.
Many essential oils such as peppermint, lemon and orange are commonly used to flavor desserts, candies and chocolates. Other, more herbal oils, such as thyme and marjoram are better suited for flavoring savory foods such as stews and sauces.
The main limitations of essential oil use in foods are: causing sensory changes in foods (due to their strong odor and flavor and their color, which may taint foods), essential oils from the same plant species presenting a high variability in quality and quantity of bioactive constituents, and such bioactive compounds potentially being lost or reduced by many food processing techniques or even essential oil extraction techniques.
There are five main methods of extraction:
• Expression
• Hydro- or water-distillation.
• Water and steam distillation • Steam distillation
• Solvent extraction
The choice of extraction method will depend on the nature of the material, the stability of the chemical components and the specification of the targeted product.
Essential oils to flavor food
