Botanical Extraction

Antioxidants in plants and extraction methods

Antioxidants in plants and extraction methods
Written by Robert Hammell

Oxidative stress is an unavoidable reaction humans experience when exposed to excessive quantities of oxygen. Sources of this oxidation include alcohol, tobacco, other harmful chemicals, and obesity. To counteract these negative reactions, it is vital to consume antioxidants to balance out the oxidative effect. 

Antioxidants come from a variety of plants, but exist primarily in the forms of polyphenols, carotenoids, and vitamins. Consumption of antioxidants has been shown to have anti-inflammatory, anticancer, anti-aging effects as well as other long-term health benefits.

By maintaining a balanced diet of fruits, vegetables and other plants, it is possible to produce a plethora of positive reactions in our body.

Benefits of Polyphenols

The first type of antioxidant are polyphenols, which are commonly found in fruits, vegetables, and grains in the form of phenolic acids, flavonoids, lignans, and stilbenes. The highest concentrations are found in fruits like grapes, apples, cherries, pears, and berries which can contain 200-300 mg of polyphenols per 100 g of fruit. Additionally, they are also present in cocoa, red wine, olives, turmeric, and tea, though in lower concentrations.

No matter the source, a high dose of these plant based antioxidants can have numerous health benefits. First, polyphenols can provide anti-inflammation and immunomodulation effects. Not only does this provide short term pain relief, but it also contributes to long term health by minimizing consequences of chronic conditions. 

Speaking of long term benefits, these antioxidants have been connected to neuroprotective benefits and improved heart health. Adding cancer and diabetes prevention to that list helps to cement polyphenols as significant contributors to long term health benefits.

Common Carotenoids

Carotenoids are a natural pigment that give many plants their color in the form of β-carotene, lycopene, lutein, and zeaxanthin. These antioxidants are most common in colorful plants like pumpkins, mangos, carrots, and all green or yellow vegetables. Lycopene is also what provides the red color to tomatoes and peppers. 

While color serves an evolutionary function by making these plants seem more appealing, there are also additional health benefits that come from carotenoids as well.

 Like polyphenols, carotenoids have been linked to cancer prevention, specifically in the breast, prostate, and colon. Additionally, because carotenoids have the potential to be converted into vitamin A, these antioxidants have demonstrated various improvements to eye health.  This may be the source of the old wives’ tale about how carrots strengthen your vision, but there is not enough evidence to confirm this.

 Finally, carotenoids can provide long term benefits like improved cardiovascular health and increased immunity. Meaning, it pays to eat vegetables along with fruits.

Plant Based Vitamins

Vitamins’ positive health benefits are so well known that an entire industry has emerged just to sell them in concentrated forms. In addition to the eye health provided by vitamin A, there are several other plant based vitamins that can greatly improve health. The first is of which is vitamin E. This vitamin is most commonly found in vegetable oils like corn, soy, sunflower, nuts like peanuts, hazelnuts, and particularly almonds as well as green vegetables like spinach or broccoli. Vitamin E can help to protect against free radicals, or unstable molecules resulting from metabolic processes within the body. 

Free radicals emerge from natural bodily functions, but they can also emerge from smoking or exposure to x-rays, industrial chemicals, or pollutants. Another vitamin that also protects against free radicals is vitamin C. Commonly found in citrus fruits, strawberries, cherries, and vegetables like broccoli, cabbage, and potatoes, vitamin C is one of the most ubiquitous foodborne vitamins. 

In addition to defense against free radicals, both of these vitamins can help strengthen immunity, promote heart health, and may prevent memory loss.

 Ultimately, consumption of vitamins and the other plant based antioxidants provide numerous long term benefits, but there is an additional way to boost their intake beyond eating fruits and vegetables. 

Extraction Methods for antioxidants

The extraction of antioxidants is not only vital to produce concentrated forms for consumption, but also to be able to isolate and quantify the effects they have on the human biological system. 

One of the most efficient ways to do this is ultrasonic assisted extraction (UAE), which relies on compression from sound waves to increase pressure within in plant material. The pressure builds up, increasing the temperature and in turn breaking down the cell walls for easier extraction. The frequency and intensity of the sound waves play a role in extraction efficiency, but so does the solvent material used. 

Similar to UAE is microwave assisted extraction (MAE), which relies on electromagnetism instead of sound to produce a similar effect on plant cell walls. One advantage to MAE over UAE is it is possible to perform this extraction without the use of a solvent, making it a greener alternative. 

Another green extraction method is enzyme assisted extraction, which relies on enzymes to isolate the antioxidants from the rest of the plant material. To minimize the environmental impact, it is possible to source these enzymes from other organic material like bacteria or fungi, but this is not always the case. 

Other extraction methods rely on solvent manipulation to maximize their yields. This could include pressurized liquid extraction, supercritical fluid extraction, or high hydrostatic pressure extraction. Each one of these uses solvents in different ways to extract the antioxidants from the plant matter.

All of these methods represent green, sustainable extraction techniques, but multiple variables will determine which one provides the most efficient results in terms of energy output compared to yield.

About the author

Robert Hammell