Supercritical fluid extraction of natural flavors
In recent years, supercritical fluid extraction technology has been widely used in various heat-sensitive, high-boiling substances for purification and separation, and has made great progress in applications and research in the fields of chemical, food, pharmaceutical, fragrance and chemical analysis.
In the fragrance industry, it is difficult to artificially synthesize some of the key aromas and aromas of natural flavors with the state of the art, and it is not harmful to the environment.
Therefore, how to effectively extract and extract the flavors and fragrances that people need from natural raw materials has become a research topic.
Due to the traditional methods of steam distillation, rectification, solvent extraction, leaching, pressing, etc., in the process of extracting perfume, it is prone to thermal decomposition, solvent residue, or partial aromatics volatilization loss.
Supercritical fluid extraction technology can solve these problems and obtain high-quality flavors and fragrances that can maintain natural color, aroma and taste.
Selection of supercritical fluids
The fluids that can be used for supercritical extraction are CO2, ammonia, ethane, propane, ethylene, toluene and freon, etc., but the most popular fluid for supercritical extraction of natural flavors and fragrances is CO2.
This is due to: CO2 has a critical point of 31.1 ° C and 7280 KPa. The extraction temperature is generally about 40 ° C, which is particularly advantageous for heat sensitive materials, and the aromatic components do not thermally decompose.
CO2 is an inert gas. During the extraction of flavor and fragrance, the aromatic component is not susceptible to oxidative deterioration.
CO2 has stable chemical properties, no burning, no corrosion, safe and non-toxic, easy to separate from extracts, no residue. 4 In particular, CO2 has good solubility for aromatic, non-polar or weak aromatic compounds such as esters, ketones, and terpenes, and many polarities such as proteins, sugars, glycosides, and phospholipids.
The substance is almost insoluble, so it is especially suitable for the extraction of natural flavors and fragrances.
CO2 supercritical fluid extraction process and equipment The use of supercritical CO2 fluid to extract natural flavors and fragrances generally does not work at high temperatures, but the working pressure is high.
At present, batch extraction processes are used. The equipment is generally made of stainless steel pressure vessels.
The CO2 is compressed by the compressor through the filter and then enters the extractor (used by several extractors in order to improve the working efficiency), and is extracted and extracted in the extractor with the pre-packed natural flavor raw material.
The fluid containing the extract then enters the separator where it is depressurized and separated, the solubility of the solute (extracted perfume) in CO2 is reduced, and the solvent CO2 is withdrawn from the top of the separator and returned to the compressor for recycling.
CO2 supercritical extraction of natural flavors and fragrances
It is hoped that the extracted natural flavors and fragrances will retain their original natural aroma and natural color as much as possible, while CO2 supercritical extraction technology can achieve both extraction and assurance.
The fragrances retain their natural aromas and aromas while retaining their natural qualities.
For example, people have used this method to extract high-quality essential oils from fragrant flowers such as lilacs, roses, and the like, and extract high-quality essential oils from edible spices such as almonds, star anise, and mint.
Flavors and fragrances obtained by conventional methods are often difficult to maintain their original flavor.
For example, ginger oil is extracted from ginger, and the traditional steam distillation method not only takes a long time for heating, but also has low oil yield and cannot extract gingerolin component, and supercritical extraction method can simultaneously obtain volatile oil and gingerol.
Another example is lilac with a unique floral aroma. With the conventional steam distillation method, since a part of the fragrant component is decomposed during the distillation, the obtained essential oil does not completely reflect the floral scent. When the essential oil is obtained by CO2 supercritical extraction, it has a perfect floral aroma.
Compared with the separation extraction method, supercritical fluid extraction has many irreplaceable advantages, which can meet some special requirements in many industrial fields, but the high pressure technology and equipment required are not conducive to its popularization and application, but The production of high-value flavors and fragrances industry has aroused great interest and has achieved great success.
In addition, the combination of micronized technology and supercritical fluid extraction technology can greatly increase the extraction rate and shorten the extraction time. Recently, the combination of electric pulse, ultrasonic wave, magnetic field and supercritical fluid extraction technology has attracted people’s attention. These aspects of research are likely to bring amazing effects, further promoting the application of supercritical fluid extraction technology in the flavor and fragrance industry.
In short, supercritical fluid extraction technology is a highly promising high-tech separation method. The prospects in the flavor and fragrance industry are very bright. Of course, there are still problems to be solved.