Have you ever wondered what plant extraction is and why is it important? It’s a process that intends to extract certain specific components that are present in plants. During the operation, a solid object (in this case a plant) is placed in contact with fluid, called the solvent and the components are separated from the plant. Plant components of interest must be contained within the solvent and that’s how you get the desired extract.
In order to isolate the extract, you must eventually eliminate the solvent, except if you need it for the food industry. In all other cases obtaining a dry extract is possible with a second separation process.
If you are interested in this topic, please continue reading. Today you will find out what no one tells you about plant extracts, how to get them and learn the facts about the general process. Let’s begin!
Plant Extracts – Where Are They Used?
Removing the tissue of a plant and creating a plant extract has many purposes. An extract usually has particular desirable properties of substances you need for various sectors. For example, they are often used in the food industry. Products made from peppermint, ginger, vanilla beans, lemongrass, cardamon, coriander, etc. are very popular and often used, but there are less conventional ways to use plant extracts in the food and beverage sector (e.g. antioxidants, texturizers, etc.)
Still, the food industry isn’t the only sector that has many benefits from plant extracts. Additives, chemical replacers, processing aids, pharmaceuticals for therapeutic properties are some great examples. Don’t forget about cosmetics whether it is for beauty, well-being, or preventive and curative.
Many sectors have a clear definition for an extract. For instance, take a cosmetic product. Any substance is intended to be placed on a human body (skin, hair, lips, nails, genital organs, etc.) or on teeth and oral cavity (with the purpose of cleaning them and keeping them in good condition). As you see, this must be clearly defined and transparent. Plant extracts are very important in the cosmetic world, especially for a good skin-care routine. Most serums and anti-aging products nowadays contain beneficial substances from plants.
Sometimes one extract can be very common in different sectors, mainly based on the chemical description. Still, every industry has a unique technology and it’s never completely the same. They also have different regulations and claims.
Still, there are some regulations everyone needs to respect. Here is a list:
- The physical and chemical request in terms of description (genotype, physical recognition, TLC)
- Regulation of nitrates, heavy metals, residues, solvents, pesticides, foreign bodies, additives, etc.
- The quality constraints, referring to toxicity, allergens, irradiation, adulteration, stability, activity, traceability, sustainable resources, etc.
- Clear regulations in terms of solvent, assay, environmental components, registration, labeling, legal uses, certification (ISO, GMP), claims, etc.
Uses Of Plant Extracts In The Food Industry
Plants have always been used in the production of many beverages, for example – cocoa, tea, coffee, cola, wine, beer, kava, etc. since ancient times in many different cultures. Camellia sinensis or, as we like to call it, tea was very popular in ancient China. Coffee was found in the region of Ethiopia called Keffa but it was actually cultivated in Yemen in the ninth century. And did you know that noble Aztecs used to consume raw cocoa beans? Sometimes they mixed them with different herbs and red peppers. All these substances are considered a stimulant because of caffeine content.
Wine is another beverage that is very important. Many studies have shown that consuming red wine in moderation can reduce cardiovascular disease and cancer, due to the presence of resveratrol. Consuming beer in moderation also has many health benefits. It can prevent kidney stones, lower your cholesterol levels, reduce stress, and help your cognitive function. It’s also very nutritious compared to other alcoholic beverages and contains high levels of vitamin B.
The Technical Process
Plant extraction is a solid/liquid extraction defined as a process of separation of one or more constituents from a solid object by solubilization in a fluid, known as a solvent. The solvent is usually liquid or a gas. Plant extraction can eventually be followed by purification stages.
The solid object is always homogeneous in thermodynamics, which means that it will undergo no modifications in the absence of external disturbances. On the other hand, heterogeneous mixtures can be fractioned by decantation, filtration, and centrifugation. With plant extraction, the disturbance is actually an exchange of mechanical and thermal energy with the surroundings, combined with the solvent.
This procedure can be scaled in a few different ways:
- Maceration (on room temperature)
- Decoction or reflux (at the boiling point of the solvent)
- Digestion (the temperature is maintained somewhere in between)
- Infusion (you need to pour boiling solvent over a plant and let it cool)
- Percolation or leaching (in this case the solvent must pass through the biomass)
These methods can be combined with each other or with other processes, for example – rectification, distillation, or steam distillation. Various solvents can be used as well as extraction aids (reverse osmosis, ultrafiltration, high pressure, ultrasound, microwaves, or supercritical CO2).
Many factors have an impact on the quality of extract, so it’s important to experiment and combine various techniques. The raw material is considered the most important factor, but other parameters can seriously affect the plant extract. Geographical origin, climatic conditions, or cultivation practices certainly mustn’t be disregarded, which makes it even more difficult to have a consistent quality.
For centuries plants have provided us with many essentials, including life-saving substances. But did you know that only 10% of all plant species have been biologically screened? Who knows what the future holds!
Plants are going to remain the essential component in the search for new medicines, production of healthy crops, fruit, and vegetables (through botanical insecticides), and cosmetic formulations as well. Not to mention essential oils which have been used for thousands of years. There are many benefits of plant extracts for human health and they are increasingly becoming an important part of our lives.