2023-05-15 19:09:07
For years, the industry has regularly used chemical substances and thermal technologies to obtain compounds –aromatic substances, vegetable oils, antioxidant products…– from plants and food. However, these activities are currently raising concerns about their possible effects on health and the environment.
To face the new challenges, there have been green technologies that allow to isolate and recover these compounds with the minimum possible damage. Each of them has its advantages and disadvantages. Let’s get to know them better!
1. Supercritical extraction with carbon dioxide
In recent years, this technique has been recognized as an “environmentally friendly technology”, as confirmed by many studies.
His main advantage is that it allows for a toxin-free extraction using solvents (chemical compounds to dissolve, suspend or extract other materials) that change state when subjected to high pressure conditions and mild temperatures.
Author provided
Although it is not the cheapest technology, thanks to supercritical extraction functional products are obtained without affecting their properties or natural ecosystems. Thus, for example, coffee beans and tea leaves are decaffeinated, the bitter flavors of hops are separated, and various aromatic substances are obtained from plants.
2. Pressurized liquids
This technique, one of the most popular today, consists in separating solids and liquids with solvents considered safe (such as ethanol) using high pressures or high temperatures for short periods. This means that their toxicity is low at the time of use and that there are no risks during their consumption.
An example of its application is the extraction of substances of high biological interest such as fatty acids, carotenoids, vitamins, polysaccharides and phenols from microalgae. Beneficial for health due to its antioxidant and anti-inflammatory effect, new food and pharmaceutical products are created with them.
Pressurized liquids are also used to obtain vegetable oils from peanuts, soybeans, and flax, castor, sunflower, or cottonseeds.
3. Ultrasound
This technique is considered as one of the most promising to recover phenols (from chia seeds, dragon fruit peels and grapes), vitamins, polysaccharides, cannabinoids and other compounds from botanicals.
The principle of ultrasound is to form bubbles with high and low frequencies of sound waves, which are used to traverse the solvent and recover useful compounds.
Another interesting feature is that it applies short operating times and mild operating temperatures, which makes it possible to extract high quality components in a simple, cheap and efficient way.
4. Electrical pulse fields
This technology makes irregular and repetitive use of high-intensity, short-duration electric fields.
It works like this. Food is placed between a pair of electrical conductors to trigger the phenomenon of electroporation –the appearance of pores on the cell membrane–, which favors the passage of fluids. Thus the desired components are obtained and, at the same time, pathogenic microorganisms can be eliminated.
Compared to other techniques, its main advantage consists in using organic solvents (such as ethanol or propanol), with good yields in short times and without affecting the organoleptic characteristics of the food.
It should be noted that green technologies not only help to obtain useful compounds safely and naturally, but by combining them we can increase their properties for longer.
Currently they are used much more in developed countries, but developing countries are also beginning to incorporate them into their food processes to shorten processing times, avoid the use of hazardous solvents and minimize the impact on the environment.
Thus, substituting traditional techniques, we will be able to create the functional foods of the future with today’s ingredients.
#Green #technologies #extract #essence #plants #food