How are plant essential oils valuable as functional ingredients?
What is natural essential oil?
Essential oils, also called natural essential oils, are derived from the steam distillation of plant components, like seeds, flowers, leaves, stems, aromatic woods and roots and retain the flavour and smell of their source [1].
Introduction
Essential oils are colourless liquids consisting of organic, aromatic, volatile and lipid-soluble molecules. They are widely used as a perfume due to their distinctive scent. About 3000 essential oils have been identified till now, and 300 of them are used in perfumery. In addition, plant essential oils have also played a role in the defence mechanism of plants and, therefore, have medicinal properties [2]. They are used extensively in aromatherapy, an alternative medicine that gained attention in the early 20th century.
In the food and beverage industries, they are used as flavouring agents-for example, vanilla essential oil and cardamom essential oil. The Food and Drug Administration has categorised about 300 essential oils as Generally Recognised as Safe (GRAS). Recently, they have gained attention for their use as natural food preservatives due to their antimicrobial and antioxidant properties. There is also an increasing interest in incorporating essential oils as a valuable ingredient in dietary supplements and nutraceuticals [1].
Essential oils as food preservatives
Essential oils are rich in bioactive compounds, and there are multiple mechanisms involved in their antimicrobial activity, for they are significantly different in their chemical structure. However, the hydrophobic nature of the bioactive compounds destroys the bacteria, thereby preventing food degradation, leading to increased shelf life and functioning as a food preservative. Research has shown that lemon essential oil, oregano essential oil, rosemary essential oil and vanilla essential oils can be used to preserve seafood, meat, fruits, vegetables and cereal products. There has also been research on using essential oils in bakery products [3].
Essential oils as functional ingredients
- Probiotics have been gaining attention in recent years for restoring the microbial balance in the digestive system and promoting digestive health. Probiotics contain microorganisms such as bacteria and yeast and are available as fermented food. They can also be added to other food products and dietary supplements. Yoghurt is the most common probiotic-enriched food and has shown benefits like supporting immunity and preventing age-related weight gain.
Since essential oils have antimicrobial properties, they can be used with probiotics to treat pathogenic infections in the digestive system. Flavoured curd, flavoured yoghurt and fermented drinks from milk are some examples of essential-oil-enriched probiotics. In addition, the anti-inflammatory properties of the probiotics were also significantly increased. Examples of essential oils included in probiotics are- eucalyptus, myrrh, Mexican mint and holy basil. In addition, the shelf-life of these products was also significantly increased.
- Essential oils have also been studied for managing inflammatory bowel disease. Essential oils from coriander showed a reduction in the symptoms of Ulcerative Colitis (UC) in rats and can potentially be used to manage the symptoms of Ulcerative Colitis in humans. Other essential oils researched for managing the symptoms of Irritable Bowel Disease Include lavender, lemon and myrtle.
- Other disorders where essential oils could be used to manage their symptoms include metabolic disorders like diabetes, hypertension and obesity and protect liver health and promote digestive health, owing to their anti-inflammatory properties.
- One drawback of essential oils is their intense aroma and flavour, and techniques like microencapsulation have been studied to mitigate this undesirable effect [1].
Conclusion
Essential oils have been gaining attention as preservatives used in food, and there have been studies on the beneficial effects of essential oils when used as a functional ingredient in nutraceuticals and supplements. Techniques like microencapsulation could be implemented to reduce their intense flavour and aroma, and thus they can be incorporated as a nutraceutical into functional foods and beverages.
How the Food Research Lab can help
The Food Research Lab offers ingredient development solutions for clients worldwide. We thoroughly assess the suppliers and food raw materials for their safety and quality. Apart from developing products, we ensure the beverage, nutraceutical and food product label adheres to the regulations, making them successful.