In an era where information is at our fingertips, consumer behavior has evolved significantly. With greater access to knowledge via the internet and social media, people are now more informed and discerning about their purchases. This shift has compelled companies to adapt their marketing strategies to meet the expectations of this informed consumer base, with a notable pivot towards products that are less reliant on chemicals and more on organic, natural ingredients. This movement, however, is not without its challenges, as the authenticity and effectiveness of these “natural” claims are sometimes questionable.
Plant extracts have emerged as a key ingredient in this new wave of product development, celebrated for their natural properties and benefits. These extracts are aqueous solutions or suspensions of bioactive molecules, derived from various parts of plants. The extraction process is designed to harness these bioactive molecules for incorporation into hair or skincare formulas, offering therapeutic or cosmetic benefits for the scalp, hair, and skin.
In our exploration of this topic, we delve into the specifics of plant extracts: their preparation, the common types used in hair care products, and the advantages they bring, particularly for those with curly hair. To ensure that our discussion is grounded in scientific accuracy and industry knowledge, I’ve sought the insights of a hair scientist and cosmetic formulator who holds a PhD in Chemistry. His expertise will guide our understanding of how plant extracts can be optimally used in hair products to achieve the desired benefits without compromising on safety or efficacy.
What are Plant Extracts?
As the name suggests, plant extracts are plant-derived compounds that are used as ingredients in products.
Plant extracts are aqueous solutions or suspensions of bioactive molecules extracted from different parts of plants.
The goal is to access these bioactive molecules and then use them in a hair or skin care formula that will give users therapeutic or cosmetic benefits for their scalp, hair, and skin.1
For centuries, humans have relied on plants to heal ailments and topical beauty applications. These natural extracts now serve a much broader range of purposes from pharmaceuticals to cosmetics products.
Overtime, extensive scientific research has been carried out to uncover new plant sources and extraction techniques, as well as formulate methods of incorporating these bioactive molecules into products that are easily accessible for consumers.
Nowadays, customers are looking for eco-friendly solutions to their hair and skin concerns. Worrying about an ingredient’s biodegradation rate, its bioavailability, and how it interacts with other ingredients has driven formulators to seek out greener options.
Particularly in hair care, research work is focused on finding a new range of bioactive molecules to improve scalp quality, hair fiber health, stimulate hair growth, and address the hair loss and other related concerns.2
Now, let’s take a detailed look at the most prolific botanical extracts and their cosmetic benefits to hair.
Plant Extracts: How Are They Made?
Numerous extraction methods have been recorded by analytical chemists and botanists alike.
The first step is to choose the desired part of the plant, which could be a plant’s flower, bark, nascent leaves, fresh or dried fruit, or even the roots.
A common extraction process involves multiple steps, such as:
• Obtaining and selecting the desired parts of the plant body, and removal of undesired materials.
• Cleansing with water without compromising the natural texture of the plant and without damaging the plant body tissues. This generally involves rinsing off plant body parts at a normal temperature without using any surfactant.
• Drying the plant body parts under the shade (avoiding direct solar radiation), or in an oven at 40 degrees Celcius and controlled humidity.
• After the extraction process has been completed, a crude extract will be obtained. In order for this to be suitable for cosmetic formulations, it must then go through purification and concentration processes.
Different Methods of the Extraction Process
The extraction process can be carried out via different methods:
Steam Distillation
Plant body parts are soaked in distilled water and the liquid is boiled in a closed container. Vapors are condensed using a condenser and the condensate liquid is collected.
Extraction Under Vacuum
This process is the same as steam distillation, except the entire procedure happens within a closed container with a negative internal pressure.
The apparatus is connected to a vacuum pump, which accelerates the boiling process and requires low heating input thus, extraction can be carried out at low temperatures.
The goal is to extract heat-sensitive biomolecules, minimize their evaporation, improve their stability, and preserve them during the extraction process to obtain higher bioactivity of the final extract.
Crude extract is purified and further concentrated under vacuum. The extract can be solubilized in water-glycerin or water-propylene glycol mixture to have higher solubility for organic components of extract.
Solvent Extraction
Solvent extraction uses organic solvent instead of distilled water. Generally, alcohols are used e.g. ethyl alcohol, propyl alcohol, or even acetone, and sometimes alcohol is mixed with distilled water (mixed solvent system).
With higher solubility in alcohols, some biomolecules from plants make it easier to achieve a higher concentrated solution of bioactive molecules.
Can We Make Plant Extracts at Home?
Yes, we can! There are various plant extraction methods that can be done at home.
Here is a simple step by step process for plant extraction:
- Gather the plant material you are looking to extract. This can include plant stems, leaves, flowers, fruits, or roots.
- Soak the plant body parts (e.g. flowers, roots, or dried leaves) in a measured amount of drinking water. For optimal comfort, heat the water to between 40-50 degrees Celsius.
- Leave this soaking solution overnight in a closed container.
- The next morning, filter the liquid and use the filtrate liquid as an extract for your cosmetic formulation.
Remember:
This is a foolproof way to extract bioactive molecules at home. There may be low concentrations of these molecules, yet the most important thing to remember the chemical composition of the extract may vary for each batch you make.
Furthermore, homemade extracts are not always effectively preserved, so you’ll need to store them in the freezer if you wish to extend its shelf life. Also, you may have to prepare the extract every time you need it.
Examples of Biomolecules in a Plant Extract
A typical plant extract may contain more than 100 active molecules having different chemical and biological properties.1
It may have:
• Terpenoids
• Alkaloids
• Polyphenols
• Flavonoids
• Carbohydrates
• Lipids
• Hydroxy acids
Organic molecules are incredibly beneficial for the scalp and hair health due to their multifunctional properties. As a result, plant extracts can be deemed as a multifunctional ingredient!
Not only do they stimulate blood circulation in the scalp, but its polyphenols protect your hair and scalp against solar-induced oxidative damage.
Alkaloids and hydroxy acids provide a soothing effect and regenerative impacts on scalp cellular turnover.
Common Extracts in Hair Products and How they Benefit Hair
With so many plant extracts readily accessible to formulators, it’s hard to pick just a few examples that are used the most.
Let’s dive deeper and explore a selection of them below which are often used.
Green Tea (Camellia Sinensis)
Green tea is one of the highly sought and used extracts in hair and skin care formulations. It is a rich source of polyphenols offering antioxidant activity.
This soothes the scalp, addresses any inflammation, and accelerates wound healing. In a hair cleansing formulation, it lowers the irritation potential of surfactants making the formulation skin-friendly and mild.3
Aloe Vera Gel, Juice, or Extract
Aloe Vera is another commonly used bio-sourced extract often used in a formulation. The gel, extract, or juice might vary a little in their chemical composition; however, carbohydrates make up the major portion of it.
For centuries, people have been leveraging the remarkable anti-inflammatory benefits of aloe vera. It hydrates scalp cells by inhibiting the transepidermal water loss and enhancing the follicular activity.1, 4
Sugar Cane Extract
Sugar Cane extract has been used in shampoo and moisturizing hair conditioning products. The extract contains alpha hydroxy acids, which are known hair and skin moisturizing actives.
Moreover, the extract contains vitamin C, fructose, and sucrose, which enhance the hydrating efficacy of the extract.
Apple Extract
Apple extract is an excellent choice for its moisturizing benefits. It is rich in sugar molecules and polyphenols which offer scalp hydrating and protection against aging.
Chamomile Extract (Matricaria Recutita)
Chamomile extract is a popular choice as an anti-irritant active. The chemical composition of chamomile extract comprises flavonoids, coumarins, essential oils, and polysaccharides.
Not only does it provide calming relief to the scalp, but its mild formulation also helps neutralize free radical species that can cause oxidation damage to your hair and scalp cells.
Coffee Extract
It contains caffeine, essential oil, carbohydrates, proteins, organic acids (chlorogenic, caffeic), tannic acid, and cellulosic derivatives.
Coffee is known for its antioxidant benefits to preserve the integrity of the hair shaft and inhibit scalp cell aging.
Eucalyptus Leaf Extract (Eucalyptus Globulus Leaf Extract)
The extract contains eucalyptin, polysaccharides, and essential oils having eucalyptol, terpineol, and pinene.
Not only does it possess potent antiseptic properties that support wound healing and combating inflammation, but enhances hair luster and makes them glossy and shiny.5
Lemon Peel Extract (Citrus Limon)
The citrus fruit family is renowned for their abundance of vitamin C, which provides powerful antioxidant benefits.
Lemon peel extract further adds a revitalizing and purifying sensation to hair and skincare formulations alike.
Do Extracts Contain Protein?
Yes, they may contain small fractions of soluble proteins. However, they may not comprise the majority of the extract composition. Most plant extracts contain carbohydrates, polyphenols, certain essential oils, and vitamins, while proteins are present only in a small concentration range.
Summary
Plant extracts are multifunctional ingredients offering a wide range of benefits to scalp and hair fibers. The high concentration of polyphenols makes these extracts an excellent remedy to combat free radical-induced hair damage. These extracts are not only incredibly hydrating but also actively improve the water levels of scalp cells and hair fibers.
References
1. Burlando, B.; Verotta, L.; Cornara, L.; Bottini-Massa, E., Herbal Principles in Cosmetics: Properties and Mechanisms of Action. CRC Press: 2010.
3. Khan, I. A.; Abourashed, E. A., Leung’s Encyclopedia of Common Natural Ingredients: Used in Food, Drugs, and Cosmetics. Wiley: 2011.
4. Hamman, J. H., Composition and applications of Aloe vera leaf gel. Molecules 2008, 13 (8), 1599-1616.
5. Mamada, A.; Ishihama, M.; Fukuda, R.; Inoue, S., Changes in hair properties by Eucalyptus extract. Inter. J. of Cosmet. Sci 2009, 31 (6), 475-475.
