témavezető: Kózelné Székely Edit
helyszín (magyar oldal): BME Kémiai és Környezeti Folyamatmérnöki Tanszék helyszín rövidítés: BME
A kutatási téma leírása:
Natural extracts, while the range and type of compounds depends on the selected solvent, always include a large number of different chemicals. When the solvent is evaporated the extracts are typically sticky, gelly, dark complex materials, very often difficult to handle. Even the solvent removal is problematic while it is necessary to avoid bacterial contamination: foaming and degradation of thermally sensitive compounds is often observed if evaporation is applied; vacuum dryers require a lot of time and the extract sticks to the plates in the dryers, it is difficult to remove; lyophilisation is a good but rather expensive option for mainly water extracts. Refining of natural extracts can be performed by several liquid – liquid extractions and column chromatographies.
Antisolvent fractionation with supercritical carbon dioxide recently gained attention in the scientific literature. Supercritical fluid extraction has worldwide large scale sites (>300 processing plants) for natural extract production, however this is only applicable for the selective recovery of relatively nonpolar components having relatively low molecular mass like oils, fitosterols, colorants, etc. Other families of compounds, very common in plants, are not soluble in supercritical carbon dioxide to an extent of designing economic recovery techniques. Most important examples of such chemical groups are polyphenols, bioflavonoids, typical antioxidants, tannins, some alkaloids and in general the glycosylated forms of nonpolar components. In the recent years our attention turned to the separation of valuable bioactives for different purposes from a single plant raw material. Besides the combination of extraction techniques (e.g. supercritical carbon dioxide and hydroalcoholic extraction still resulting safe products with non-restricted solvent residues only, suitable for organic –bio- products as well) further processing of industrial residues (e.g. essential oil production) is also an exciting possibility with clear environmental and economical benefits. As an option antisolvent fractionation was also tested, with great success. Aim of the doctoral research is to develop novel separation processes and gain a deeper understanding on the applicability on the antisolvent processes for the purification of natural extracts.
felvehető hallgatók száma: 1
Jelentkezési határidő: 2018-05-22
2024. IV. 17. ODT ülés Az ODT következő ülésére 2024. június 14-én, pénteken 10.00 órakor kerül sor a Semmelweis Egyetem Szenátusi termében (Bp. Üllői út 26. I. emelet).
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