In recent years, with the gradual launch of various natural concept cosmetics, the consumer demand for personal care products containing natural ingredients has continued to grow, and plant extracts have become increasingly important in cosmetics, which also requires various plant extracts to be further optimized in terms of safety and efficacy.
Supercritical CO2 extraction Process can not only complete deacidification, decolorization, and deodorization in the extractor at one time, but also use CO2 as an extractant to ensure the characteristics of no pollution, no residue, and pure natural.
Compared with traditional extraction methods, SFE has great advantages in the purity, yield, active ingredient content, color and aroma of essential oils in the extraction of plant extracts and essential oils.
Application advantages of supercritical CO2 extraction te
(1) In terms of the purity of extract products: Magnolia officinalis is an important traditional Chinese medicinal material in my country, and its main active ingredients are magnolol and honokiol. Because of its significant antibacterial and antioxidant effects, it can be used as an effective ingredient in food, health products, medicines and daily chemical products. Traditional extraction processes have the disadvantages of low yield, low purity and dark color. Luo Andong et al. extracted Magnolia officinalis extract using supercritical CO2. After simple refining, the purity of its active ingredients can reach more than 98% [4]. At present, plant extracts extracted using supercritical CO2, such as Polygonum cuspidatum extract, Cnidium monnieri extract, and Paeonol, can reach a purity of more than 98% after simple refining. The industrial production of these extract products has become quite mature.
(2) In terms of improving the yield of extracts: Licorice is the root and rhizome of a perennial herbaceous plant in the Leguminosae family. Its extracts, glycyrrhizic acid and glycyrrhizic flavonoids, are the preferred active ingredients in cosmetics. However, the high prices of these two products have forced engineers to use other raw materials to replace these two products in some cosmetics. Comparison between supercritical CO2 extraction technology and traditional extraction methods found that the yield of glycyrrhizic acid extracted by supercritical CO2 extraction technology is 8-12 times that of traditional extraction methods [5], and the extraction yield of glycyrrhizic flavonoids is also increased by 1-1.5 times [6,7]. This has also laid a solid foundation for the large-scale application of these two raw materials.
(3) In terms of removing odor from plant extracts: Spirulina is rich in protein and a variety of bioactive ingredients. It has good skin care ability in cosmetics. It not only has good moisturizing and skin care effects, but also has the ability to remove and inhibit free radicals, so it can play an anti-wrinkle, sun protection, anti-radiation, freckle removal and anti-aging role [8]. Spirulina extracted using traditional methods has a strong fishy smell. After deodorization, its active ingredients are reduced, which limits its deep processing development. The method of combining supercritical CO2 extraction technology with other extraction technologies can effectively solve the problem of removing the fishy smell without reducing its active ingredients [9,10].
(4) Extraction of effective ingredients and active substances in plant oils and fats: Lü Xuebin et al. used supercritical technology to extract pomegranate seed oil, and the content of pomegranate acid was above 80% [11]. The results showed that pomegranate seed oil extracted by supercritical CO2 is rich in conjugated unsaturated fatty acids, and the oil has no solvent residue, light color, and high nutritional value. It meets the needs of food, medical care, cosmetics and other industries for high-quality oils and fats. Similarly, the content of the active ingredient ligustilide in Chuanxiong oil and Angelica sinensis oil extracted by supercritical CO2 technology can be as high as 70% [12].
(5) Extraction of volatile oils (essential oils): Essential oils are generally extracted by solvent extraction, but the application of traditional extraction methods will cause some unstable aroma components to deteriorate due to heat, solvent residues and loss of low-boiling point head aroma components, thus affecting the aroma of the product. Non-toxic and residue-free supercritical CO2 extraction can extract essential oils and special aroma components at room temperature. Since volatile oils have low boiling points, small molecular weights and low polarity, they have good solubility in supercritical CO2 fluids and are suitable for extraction with supercritical CO2 fluids.
(6) Extraction of natural pigments: As the insecurity of synthetic pigments has attracted increasing attention, the types of synthetic pigments used in countries around the world are decreasing. Natural pigments are not only safe to use, but also have certain nutritional value and are deeply loved by consumers. Taking capsicum red pigment as an example, supercritical CO2 can be used to remove the odor and residual solvent in capsicum oleoresin, and at the same time separate the capsicum pigment into red and yellow pigments with less loss, which has obvious advantages compared with the traditional despicating process. Supercritical fluid CO2 extraction technology can also separate other natural pigments, such as lycopene, cocoa pigment and β-carotene [14].
(7) Extraction of natural antioxidants: Rosemary extract extracted from rosemary leaves is a highly effective natural antioxidant with higher antioxidant effect than VC, VE, tea polyphenols, and chemical antioxidants BHA and BHT. Because it is derived from natural plants, it can meet consumers’ demand for clean labels and natural safety. Luo Andong et al. extracted rosemary extract using supercritical CO2 technology [15]. The extract has a high content of active ingredients (carnosic acid and rosmarinic acid) and has antioxidant, moisturizing, freckle removal and skin repair effects. It is an excellent additive in cosmetics.
Conclusion
Supercritical CO2 extraction Process is not only used in the cosmetics industry, but also has a large application in other industries. For example, in the food industry, it is used to process various natural antibacterial or antioxidant extracts, extract hops, extract pigments, etc.; in the pharmaceutical industry, it is used to extract the new anti-malarial drug artemisinin and alkaloids.