超音波タバコ抽出

Facts Worth Knowing

Why is Ultrasonic Extraction so Effective?

Ultrasonically-assisted extraction (UAE) is based on coupling highly intense ultrasound waves (acoustic waves) into a liquid or slurry. The acoustic waves create alternating high pressure / low pressure cycles, which result in the phenomenon of acoustic cavitation. The phenomenon of ultrasonic or acoustic cavitation is characterized by extreme, locally confined conditions of very high pressures, temperatures and shear forces. In proximity of the imploding cavitation bubbles, temperatures of up to 5000K, pressures of 1000 atmosphere, heating-cooling rate above 1010 K/s and liquids jets with up to 280m/s velocity, which appear as very high shear force and turbulences in the cavitational zone, can be measured. The combination of these factors (pressure, heat, shear and turbulence) disrupt cells (lysis) and intensify mass transfer during the extraction process. Thereby, the liquid-solid extraction of phytoconstituents from plant cells is promoted. The ultrasonic extraction technique is widely applied for the successful and efficient extraction of flavonoids, polysaccharides, alkaloids, phytosterols, polyphenols, and pigments from plants.

Ultrasonic extraction from plant cells: the microscopic transverse section (TS) shows the mechanism of actions during ultrasonic extraction from cells (magnification 2000x) [resource: Vilkhu et al. 2011]

Tobacco

Various plants in the Nicotiana genus and the Solanaceae (nightshade) family are known as tobacco plants. Besides being the commonly used term for the plant, tobacco describes also the products prepared from the cured leaves of the tobacco plant. Whilst Nicotiana tabacum is the main crop use for tobacco and nicotine production, there are over 70 plant species of tobacco. N. tabacum is the dominant species used for tobacco products, however the more potent variant N. rustica can be found around the world and is used for.
Tobacco contains the stimulant alkaloid nicotine as well as harmala alkaloids. Dried and cured tobacco leaves are mainly used for smoking in cigarettes, cigars, pipes, shishas as well as e-cigarettes, e-cigars, e-pipes and vaporizers. Alternatively, they can be consumed as snuff, chewing tobacco, dipping tobacco and snus.

The tobacco plant family contains various (sub-)species, which exhibit different alkaloid and flavour profiles.
Oriental tobacco (Nicotiana tabacum L.) is a species of tobacco grown mainly in Turkey, Greece, and neighboring areas, which is used for the commercial production of cigarettes, cigars and chewing tobacco. It has a strong characteristic flavor, is relatively low in nicotine and high in reducing sugars, acids, and volatile flavor oil, which gives the tobacco products an intense aroma.

There are 67 natural species of tobacco known. Below the most common species are listed:

• Nicotiana acuminata (Graham) Hook. – manyflower tobacco
• Nicotiana africana Merxm.
• Nicotiana alata Link & Otto – winged tobacco, jasmine tobacco, tanbaku (Persian)
• Nicotiana attenuata Torrey ex S. Watson – coyote tobacco
• Nicotiana benthamiana Domin
• Nicotiana clevelandii A. Gray
• Nicotiana glauca Graham – tree tobacco, Brazilian tree tobacco, shrub tobacco, mustard tree
• Nicotiana glutinosa L.
• Nicotiana langsdorffii Weinm.
• Nicotiana longiflora Cav.
• Nicotiana occidentalis H.-M. Wheeler
• Nicotiana obtusifolia M. Martens & Galeotti – desert tobacco, punche, “tabaquillo”
• Nicotiana otophora Griseb.
• Nicotiana plumbaginifolia Viv.
• Nicotiana quadrivalvis Pursh
• Nicotiana rustica L. – Aztec tobacco, mapacho
• Nicotiana suaveolens Lehm. – Australian tobacco
• Nicotiana sylvestris Speg. & Comes – South American tobacco, woodland tobacco
• Nicotiana tabacum L. – commercial tobacco grown for the production of cigarettes, cigars, chewing tobacco, etc.
• Nicotiana tomentosiformis Goodsp.

The three species below are man-made hybrids:

• Nicotiana × didepta N. debneyi × N. tabacum
• Nicotiana × digluta N. glutinosa × N. tabacum
• Nicotiana × sanderae Hort. ex Wats. N. alata × N. forgetiana

Types of Tobacco
The curing and subsequent aging process of tobacco leaves induces a slow oxidation and degradation of the present carotenoids in tobacco leaf. Due to the oxidation, certain compounds in the tobacco leaves are synthesized, which result in sweet hay, tea, rose oil, or fruity aromatic flavors, which contribute to the “smoothness” of the smoke. Starches are converted into sugars, which subsequently glycate proteins, and are oxidized into advanced glycation endproducts (AGEs). This is a caramelization process that also gives the smoke its flavor.
The preparation and curing method of tobacco influences its final aroma characteristics. Curing can be achieved by air-, fire-, flue-, and sun-curing. For example, flue-cured tobacco (e.g. from France) contains only low levels of alkaloids, whilst air-cured Burley tobacco (e.g. sourced from Guatemala) is known for its high content of alkaloids.