Rosmariinin uuttaminen tehoultraäänellä

Rosemary is a fragrant, evergreen herb rich in bioactive compounds and essential oils, which are used in medicinal, food and cosmetic products. Ultrasonic extraction is a mild, yet highly efficient technique to isolate bioactive compounds and essential oils from rosemary and other herbs. Ultrasonic extraction gives higher yields and superior extract quality within short processing time.

Rosemary Extract Production with Ultrasonication

Ultrasonicators are highly efficient when it comes to production of botanical extracts. Ultrasound is a mild, non-thermal extraction technique, which allows for a gentle processing and isolation of delicate bioactive molecules from plants. As sonication applies only purely mechanical forces, damaging of heat-sensitive molecules is avoided. This allows to prepare full-spectrum extract containing numerous bioactive compounds, which interact with each other and result in the so-called entourage effect. For instance, ultrasonic rosemary extract contains high amounts of bioactive molecules such as carnosic acid, carnosol, rosmarinic acid, oleanolic acid, ursolic acid, camphor, 1,8-cineole, p-coumaric acid and caffeic acid.
To produce a rosemary extract, bioactive compounds are isolated from the needle-like leaves of the rosemary plant (Salvia rosmarinus, Rosmarinus officinalis). It is commonly used as a natural preservative and flavoring agent in the food and cosmetic industries.
 

Rosemary extract contains several bioactive compounds, including antioxidants such as carnosic acid and rosmarinic acid, which have been shown to have anti-inflammatory, antimicrobial, and anti-cancer properties. These properties make rosemary extract useful for preserving the freshness and quality of food products, as well as providing potential health benefits in dietary supplements and natural remedies.
In the food industry, rosemary extract is often added to processed meats, baked goods, and snack foods to extend their shelf life and prevent oxidation. It is also used as a natural flavouring agent in sauces, dressings, and marinades.
In the cosmetic industry, rosemary extract is used in skincare and haircare products for its antioxidant and anti-inflammatory properties, which can help to protect and nourish the skin and hair. It is also used as a natural fragrance and colorant in some cosmetic products.

The mechanism of cell wall disruption (a) breaking of cell wall due to cavitation. (b) diffusion of solvent into the cell structure.
(Graphic adapted from Shirsath et al., 2012)

How does the production of rosemary extract work using a probe-type ultrasonicator?

The production of rosemary extract using a probe-type ultrasonicator typically involves the following steps:

1. Preparation of the Rosemary: The rosemary leaves are cleaned, dried, and ground into a fine powder.
2. Uuttaminen: The ground rosemary powder is mixed with a solvent such as ethanol or water, and the mixture is sonicated using a probe-type ultrasonicator. The ultrasonicator uses high-frequency sound waves to create cavitation bubbles, which help to break down the plant material and release the active compounds.
3. Filtration: The mixture is filtered to remove any remaining plant material, leaving behind a liquid extract.
4. Concentration: The liquid extract is concentrated using a rotary evaporator or other suitable method, to increase the concentration of the active compounds.
5. Kuivaus: The concentrated extract is dried using a suitable method, such as spray drying or freeze drying (lyophilization) in order to produce an extract in dry powder form.
6. Pakkaaminen: The dry powder is then packaged and stored in a cool, dry place until it is ready for use.

The use of a probe-type ultrasonicator in the extraction process allows for a more efficient and effective extraction of the active compounds from the rosemary leaves, resulting in a higher-quality extract with a greater concentration of beneficial compounds. Additionally, this method can be used on a large scale, making it suitable for commercial production. Hielscher ultrasonicators allow for precise process parameter control and the linear scale-up of extraction process to any desired volume.

Scientifically-Proven Superiority of Ultrasonic Rosemary Extraction

In their scientific research report, Dhoubi et al. (2020) investigate the impact of different extraction methods on the chemical composition and antioxidant potency of Rosmarinus officinalis L. extracts. They compare three extraction methods: supercritical fluid extraction, ultrasound-assisted extraction (UAE) using the Hielscher ultrasonicator UIP1000hdT, and microwave-assisted extraction (MAE).

Highlights of the Study:

• The authors found that the extraction method significantly affected the chemical composition and antioxidant potency of the rosemary extracts. When compared with the other both extraction techniques of supercritical fluid extraction and microwave, ultrasound-assisted extraction gave best results.
• Ultrasonic extract of rosemary with ethanol was very rich in polyphenols.
• With sonication, higher antioxidant capacity was observed at short time extraction (10 mins).

Protocol for Ultrasonic Rosemary Extraction

The ultrasound-assisted extraction was performed in a probe-type ultrasonicator using a sonotrode (UIP1000hd, Hielscher Ultrasonics, see picture below). A mixture of powdered rosemary and absolute ethanol (1:3 w/v) was placed in a double jacket reactor and exposed to ultrasound at 750 W for 10 min. The extraction temperature was regulated at 25°C. The ultrasonic extract was centrifuged at 4000 rpm for 10 min. The supernatant was removed and concentrated under a vacuum by using a rotary vacuum evaporator.

Ultrasonic extraction setup using the Hielscher probe-type ultrasonicator UIP1000hdT for batch extraction of botanicals.
(picture: © Petigny et al., 2013)

Specifically, ultrasonic extraction produced extracts with higher concentrations of total phenolic compounds, flavonoids, and carotenoids, as well as higher antioxidant activity, compared to maceration. Additionally, ultrasonic extraction was more efficient methods, producing higher yields of extract in a shorter amount of time.
The authors conclude that the choice of extraction method is an important factor to consider when producing rosemary extracts for use in food, cosmetic, and pharmaceutical industries. Ultrasonic extraction is a promising extraction method that may produce more potent and efficient extracts with higher yields.
The research team concluded that “among the studied extracts, ultrasonically extracted rosemary exhibited higher antioxidant activity according to both antioxidant activity assays. This was related to the higher Total Phenolic Content, and particularly, carnosic acid and rosmarinic acid contents. Moreover, tested in fibroblast human cells exposed to oxidative stress, our ultrasonic extract performed a strong antioxidant activity compared to gallic acid and N-acetyl cysteine. Hence, aiming to substitute synthetic antioxidants, our ultrasonically prepared rosemary extract, a natural source of antioxidants, may be of interest for several industrial applications.”

Antioxidant activity of rosemary extracts. Blue columns: at 60°C using distilled water; Orange columns: after ultrasonic treatment.
(study and graphic: Suchkova et al., 2021)

High Performance Ultrasonicators for Rosemary and Herbal Extraction

Hielscher Ultrasonics manufactures and supplies high-performance ultrasonicators at any power and size. Our portfolio of ultrasonic homogenizers and extractors ranges from hand-held, portable devices to fully-industrial production systems for the inline processing of large volumes on commercial scale.

Suunnittelu, valmistus ja konsultointi – Laatu valmistettu Saksassa

Hielscher-ultraääniastiat ovat tunnettuja korkeimmista laatu- ja suunnittelustandardeistaan. Kestävyys ja helppokäyttöisyys mahdollistavat ultraäänilaitteidemme sujuvan integroinnin teollisuuslaitoksiin. Hielscher-ultraäänilaitteet käsittelevät helposti karkeita olosuhteita ja vaativia ympäristöjä.

Hielscher Ultrasonics on ISO-sertifioitu yritys ja painottaa erityisesti korkean suorituskyvyn ultraäänilaitteita, joissa on huipputeknologia ja käyttäjäystävällisyys. Tietenkin, Hielscher-ultraäänilaitteet ovat CE-yhteensopivia ja täyttävät UL: n, CSA: n ja RoHs: n vaatimukset.
Contact us now! Our well-trained, long-experienced technical staff will be glad to discuss your extraction process with you and to recommend you the most suitable ultrasonic extractor!

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