Maceration and Aromatisation by Sonication
Ultrasonic aromatisation and flavouring of edible oils is based on the ultrasonic extraction of flavour compounds from botanicals such as herbs, spices, fruits etc. Sonication is a process intensifying method, which releases bioactive components into the oil. As a non-thermal processing method, ultrasonics is predestined for the preparation of heat-sensitive botanicals and oils.
Flavoured Edible Oils
Aromatized or flavoured edible oils are defined as oils infused with vegetables, herbs, spices or fruits in order to improve its aroma and sensory characteristics. Besides the improvement of the sensory characteristics, the edible oil is enhanced by health-promoting phytochemicals, which are present in botanicals such as herbs and spices. Polyphenols, flavonoids, terpenes, anthocyanins, aromatic compounds, and polysaccharides are well known for their contribution to health and well-being. Oils such as olive oil, avocado oil, sunflower seed oil, rapeseed / canola oil and other vegetable or seed oils are an extraordinary carrier for bioactive compounds and flavours.
Ultrasonic Maceration and Aromatisation
Ultrasonic infusion of edible oils releases the phyto-chemicals and flavour compounds from the botanicals such as spices, herbs, vegetable or fruits and mixes them evenly into the oil. Due to the ultrasonic cavitation effects, the bioactive compounds are homogeneously dispersed into the oil matrix, which enhances the absorption rate and bioavailability of the health-promoting compounds in the human body significantly since the oil solubilizes the lipophilic bioactive compound.
Maceration is the technique by which delicate or highly volatile herbal essences are released from plant material in a “cold”, non-thermal process. Maceration can be described as a type of cold infusion. Since during maceration no heat is applied, the maceration is usually a slow, time-consuming process. To prepare a macerate, plant material (e.g. ground spices or minced herbs) is suspended in a liquid (so-called solvent) and left to sit or infuse for a relatively long time period, which can range from a several weeks to a few months. The duration of the maceration process is correlated with the intensity of the aroma.
Ultrasonication intensifies the maceration step significantly by applying intense micromixing and turbulences to the maceration mixture. Sonication can accelerate the traditional maceration, which takes weeks or months, drastically – achieving the same results of flavour infusion within a few minutes. As a non-thermal, mechanical method, ultrasonic maceration increases the mass transfer and preserves the heat-labil bioactive compounds such as volatiles, polyphenols and other phytochemicals. This makes ultrasonic maceration a unique technique for a rapid, effective production of high-quality macerates.
Another advantage of ultrasonic maceration is the use of fresh plant material. In traditional maceration, fresh material can be used but is prone to microbial spoilage, since the botanical material must remain for very long periods in the oil. Ultrasonic maceration is a rapid process of several minutes, which means there is no long period for microbial growth. Furthermore, ultrasonic cavitation is well-known to disrupt and inactivate microbial cells and contributes thereby to the macerate’s stability.
Ultrasonically aromatised oils such as extra virgin olive oil or sunflower oil have been shown a higher stability as the added antioxidants from the herbs reduce the primary oxidation of the oil’s fatty acids. Oregano, thyme, hot chili pepper, garlic, laurel, basil, olive leaves, sage, lavender, rosemary, menthe, lemon, orange as well as other fruits, leaves, flowers, roots, seeds and bark are rich in essential oils, polyphenols, flavonoids and other bioactive compounds. Ultrasonic maceration and aromatisation is a effective, rapid and safe method to upgrade edible oils, giving them a higher antioxidant and polyphenol content, improved oxidation stability and a rich flavour profile.
- Complete flavour extraction
- Rapid process
- Non-thermal, mild process
Flavouring and aromatising edible oils by ultrasonic maceration is a potent and rapid process to upgrade oils and produce so-called “gourmet oils”. With an broader range of flavours, ultrasonic aromatisation adds further value to oil products.
Industrial Ultrasonicators for Vegetable Oil Processing
High-power ultrasonic processors are already widely used in the food industry to extract flavours and bioactive compounds, to emulsify oils with water-based liquids, or to homogenize various materials. For flavoured edible oils, the ultrasound-assisted extraction allows for the production of high quality oils with a intense, full flavour profile. At the same time, ultrasonic maceration and aromatization convinces as a fast, convenient, safe, and cost-effective method.
For ultrasonically-assisted maceration, flavour extraction and aromatisation, whole spices (i.e. leaves, flowers, seeds, bark etc.), ground spices (i.e. powder), essential oils or oleoresin can be used.
Hielscher ultrasonics manufactures high-performance ultrasonic processors from lab and bench-top to full-industrial scale with the processing capacity of several tons per hour.
The table below gives you an indication of the approximate processing capacity of our ultrasonicators:
|Batch Volume||Flow Rate||Recommended Devices|
|1 to 500mL||10 to 200mL/min||UP100H|
|10 to 2000mL||20 to 400mL/min||UP200Ht, UP400St|
|0.1 to 20L||0.2 to 4L/min||UIP2000hdT|
|10 to 100L||2 to 10L/min||UIP4000hdT|
|n.a.||10 to 100L/min||UIP16000|
|n.a.||larger||cluster of UIP16000|
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- Maarit J. Rein, Mathieu Renouf, Cristina Cruz‐Hernandez, Lucas Actis‐Goretta, Sagar K. Thakkar, Marcia da Silva Pinto (2013): Bioavailability of bioactive food compounds: a challenging journey to bioefficacy. British Journal of Clinical Pharmacology 2013 Mar; 75(3): 588–602.
- Petigny L., Périno-Issartier S., Wajsman J., Chemat F. (2013): Batch and Continuous Ultrasound Assisted Extraction of Boldo Leaves (Peumus boldus Mol.). International journal of Molecular Science 14, 2013. 5750-5764.
Facts Worth Knowing
What is Maceration?
The traditional maceration process, by which oils such as olive or sunflower oil are infused with the aromatic compounds and essential oils of botanicals (e.g. spices, herbs, fruits etc.), is an infusion process, which works by soaking the plant material in the oil. This is a very slow process, which takes from several weeks up to a few months, since the mass transfer between the botanical solids and the oil is slow. Another factor, which is responsible for the slowness of traditional maceration, is the temperature during maceration. As a cold infusion, the suspension of botanical and oil is kept at room temperature in order to prevent the sensitive volatile compounds, oleoresins and essential oils from thermal degradation. These factors slow the process and make it very time-consuming.
The maceration process can be used to infuse edible oils, as well as oils and tinctures for skincare, medicinal tinctures and alcoholic beverages. Common herbs and spices used for the maceration of oils and tinctures include mint, basil, chilis, rosemary, thyme, vanilla, cinnamon, lavender, elderflower, calendula, St. John’s Wort, sea buckthorn and many others.
Common oils for maceration are olive, sunflower seed, coconut, jojoba, rapeseed, flaxseed or hemp oil. To prepare tinctures or alcoholic beverages, alcohol is used as liquid.
Edible oils are vegetable oils extracted from plants. These oils are triglycerides and are used in food, both in cooking and as supplements. In example, olive oil is used as cooking oil, condiment and as dietary supplement since it is rich in omega 9 fatty acids. Besides its use as food, olive oil is also used as cosmetic product for skin and hair care.
Edible oils can be extracted from fruits (e.g. olives, avocado, jojoba), nuts (e.g. walnut, macadamia,almond), seeds (e.g. canola, sunflower, flax, hemp, argan) or from citrus (e.g. lemon, bergamotte, grapefruit, which are essential oils).
A great number of different sources of natural biological active substances, also known as functional, can be potentially used to enrich edible oils such as extra virgin olive oil.
Phytochemicals are non-nutritive chemicals in plants that protect or prevents the plant against disease or vermin. When phytochemical-rich food is consumed as part of a healthy diet, these plant compounds have many positive effects on the body by acting as antioxidants, hormone stimulants, enzymatic stimulation and showing antibacterial properties.
Various kinds of plants and plant parts can be rich in phytochemicals, such as vegetables (e.g. broccoli, garlic, fennel), fruits (berries, grapes, oranges), nuts and seeds (e.g. almonds, flaxseeds, hazelnuts, macadamia, pepitas, walnuts), medinical plants (e.g. echinacea, gingko, periwinkle, valerian), herbs (e.g. hawthorn, hops, licorice, rooibos, schizandra), grains (oats, quinoa, barley) and legumes (e.g. soybeans, mungbeans, chickpeas).
Phytochemicals can be distinguished into alkaloids, anthocyanins, carotenoids, coumestans, flavonoids, hydroxycinnamic acids, isoflavones, lignans, monophenols, monoterpenes, organosulfides, phenolic acids, phytosterols, saponins, stylbenes, triterpenoids, and xanthophylls.
An essential oil is a concentrated hydrophobic liquid containing volatile chemical compounds from botanicals. Essential oils are also known as volatile oils, ethereal oils, aetherolea. Essential oils are often referred to as the oil of the plant extracted from, such as rose oil, teatree oils, or bergamotte oil. Essential oils are termed “essential” because they contain the “essence of” the plant’s fragrance. When used for essential oils, the term “essential” does not mean that the oil is an indispensable compoud, as with the terms essential amino acid or essential fatty acid, which are so called because they are nutritionally required by a given living organism. Essential oils are produced by distillation, hydrodistillation, solvent extraction or pressing. Ultrasonic processing is often used to intensify and accelerate the extraction rate and increase the essential oil yield.
Read more about ultrasonic hydrodistillation of essential oils!
Oleoresins are a natural combination of oil and resin in plants. Being a highly concentrated substance, oleoresins are semi-solid extracts composed of a resin in solution in an essential and/or fatty oil (trigylcerides).
In contrast to essential oils, oleoresins are plentiful in heavier, less volatile and lipophilic compounds, such as resins, waxes, fats and fatty oils.
Oleoresins can be prepared from spices, such as basil, capsicum, cardamom, celery seed, cinnamon bark, clove bud, fenugreek, fir balsam, ginger, jambu, labdanum, mace, marjoram, nutmeg, parsley, pepper (black/white), pimenta (allspice), rosemary, sage, savory, thyme, turmeric, vanilla, West Indian bay leaves. The solvents used are nonaqueous and can be either polar (i.e. alcohols) or nonpolar (i.e. hydrocarbons, carbon dioxide). Ultrasonic extraction method is compatible with those solvents and accelerates the extraction rate and yield.
Both, essential oils and oleoresins are excellent natural substances, which can be added as concentrated flavour ingredient to various foods and beverages. Essential oils and oleoresins are isolated from plants via extraction (e.g. ultrasonically assisted extraction) and subsequent distillation. Herbs, spices and other botanicals are used as raw materials for the production of essential oils and oleoresins.