Learn about the main processes of manufacturing plant extracts for the food industry

February 4, 2021

Reading time8 minutes

Check out 10 different methods and technologies applied to extract the active components of plants and produce natural extracts, ingredients that are on the rise in the global food and beverage market, aligned with the growing trend of consumers for naturalness, well-being and health

The steady movements of consumers in search of naturalness, healthiness and functional benefits in food have promoted a growing interest in the global food and beverage industries for ingredients that help supply this market demand. This trend gives prominence to plant extracts concentrated in active components, which offer these additional benefits and present themselves as excellent alternatives to add value to products in the most different categories and bring new business opportunities. 

Today, extracts can often be found in the most diverse products possible: carbonated drinks formulated with fruit juices, mineral waters with vitamin C, chocolate with essential fruit oils, dairy products, energy bars, snacks, cookies, sweets, soups, meat products, among others.

In the food industry, extracts are used as natural flavorings, colorants and antioxidants and as food enrichers with natural plant actives, meeting legal requirements and adding value to products. 

The active compounds are taken from the most different parts of a plant, such as the stem, leaves, seeds and fruits. Today extracts are classified as colorants, liquid extracts, soft or concentrated extracts, and dry or powder extracts.

What is extraction?

It means removing, in the most selective and complete way possible, the substances or active fraction contained in the plant, using a technologically appropriate and toxicologically safe liquid or mixture.

What are extracts?

“Extracts are products obtained by exhaustion, cold or hot, from products of animal, vegetable or microbial origin with permitted solvents. They must contain the volatile and fixed aromatic principles corresponding to the respective natural product. They can be presented as: liquid extracts: obtained without removing the solvent or partially eliminating it; and dry extracts: obtained by removing the solvent. ” (Resolution no. 02/07 – Technical regulation on additives and flavorings)  

To promote this extraction, the industry has a diversity of technologies and extractive processes. We have selected, below, the 10 main methods used in the extraction and extraction manufacturing process:

– Maceration: consists of the simple contact of the vegetable drug with the liquid extractor for a determined period of time. This maceration can be static (stopped) or dynamic (with movement), with agitation (movement in reactor) of both. 

It is indicated for the manufacture of extracts sensitive to thermal degradation, when one wants to maintain the sensorial characteristics of the plant and not exhaust the extraction of the active components. For example, a chamomile extract. 

– Infusion: boiling water or another suitable liquid extraction is added to the plant. It is the method of preparing homemade tea, but on a large scale. 

It is also widely used for plants sensitive to thermal degradation, seeking a better sensory quality of the obtained extract. For example, toasted mate, hibiscus and green tea. 

– Decoction or reflux: in this method, the extractor liquid boils in contact with the plant. 

Indicated for extraction of non-thermosensitive actives and for extraction of more rigid parts of herbs such as stems, roots and seeds. For example, catuaba extract.

– Digestion: the plant-extracting substance contact is maintained at a temperature of 40°C to 60 °C. 

Widely used to obtain fruit and vegetable extracts. Often an enzyme stage is part of digestion, to obtain extracts with more sensory and clarified impact (an operation that consists of clearing cloudy liquids). For example: açaí, plum and cocoa extracts.

– Percolation: this is the process that allows the most efficient extraction of active components by the dynamics and possible equipments. The passage of the liquid extractor through the milled plant, in equipments known as percolators with flow, time and temperature control, optimizes the process. 

It is generally used to extract non-thermosensitive actives. By this method, in many cases, it is possible to extract around 95% of the actives contained in the plant material. For example, guarana extract, quassia extract and pepper oleoresins. 

– Extraction with Supercritical CO2: in this type of extraction, CO2 supercritical fluid is used to modulate extraction, co-solvents such as ethanol can also be used. This technology is still not widespread in the industry due to its high cost and low performance. It is used for extracting essential oils. 

– Microwave Assisted Extraction (ESAM): it is an emerging extraction technique, widely used by academics and still not widespread in the industry. The use of microwave energy allows extraction with less liquid extractor. It is used to extract more polar compounds, such as oils and fats.

– Ultrasound Assisted Extraction: another emerging technique that has been highlighted because it is a method of intensifying the process, making it possible to obtain high extraction rates in less time. The cavitation ( phenomenon of vaporization of a liquid by reducing the pressure, during its movement) generated by ultrasound is known to produce several effects in the plant matrix, such as: the liquid circulation (agitation of the liquid extractor) in the system and the generation of turbulence which can assist in increasing mass transfer. This reduces the extraction time, allowing for reduced liquid consumption, in addition to extraction at reduced temperatures, avoiding thermal damage to the extract and minimizing actives losses.

Other important unit operations for the manufacture of extracts are:

– Distillation: consists of the partial or total elimination of the extraction liquid. This distillation can be simple or fractional (divided).

– Drying: when the liquid extract has its extracting substance removed by evaporation processes or is subjected to drying (to turn powder, pieces or flakes) in equipment such as spray dryer, drum dryer, vacuum dryer and freeze drying, which are the most used methods. 

Caution in the standardization of a specific compound

In general, for the extracts used in the food industry, quantification and standardization of a specific compound, which is called a chemical maker, is necessary to establish the quality standard of the concentrated extract obtained.

For this reason, even before the processing stage, there is an essential issue that directly influences the standardization of extracts in active ingredients: it is the quality of the raw materials. It is essential that the manufacturer makes a prior analysis of each batch of raw material purchased. And use the practice of sourcing, which deals with the choice of the best suppliers for the company, through extensive market research, including requesting quotes from different competitors. These actions are important to guarantee these levels of quality in raw materials.

Different analytical methods are applied to standardize plant extracts using chemical maker or active ingredients. One of the most recognized and reliable is through analysis by High Performance Liquid Chromatography (HPLC / HPLC). But Spectrophotometry and Titulometry are also used.

In addition to the quantification of actives, other physical-chemical analysis of plant extracts is necessary, such as ethanol content, humidity, total solids, pH, among others. And, when it comes to the application of these extracts in the food industry, sensory and microbiological analysis are equally important.

Food and beverage application

Studies have already identified thousands of molecules in the approximately 350 plant species consumed by humans that would have a protective effect on health. These metabolites (substances produced during metabolism), classified as phytonutrients, can play an important role in maintaining health and even preventing degenerative diseases. Among the phytonutrients that are most of interest today are polyphenols, carotenoids, phytosterols and glucosinolates, some of which are able to act against oxidative stress (this is what the situation of excess free radicals is called in comparison with the intrinsic protective system of each cell, causing premature aging, for example).

The list of active compounds of interest for application in the food and beverage industries is reinforced by antioxidants, caffeine, anthocyanins, flavonoids, amino acids, vitamins (A, B complex, C), omega (6, 9), catechins, among others. These molecules favour different appeals, such as energy, disposition and relaxation to those who consume. 

Antioxidants are also being widely used by industries as an interesting alternative to replace synthetic antioxidants (acquiring clean label appeal), due to the ability to improve the oxidative stability of food products and, in many cases, to increase their shelf life.

In Latin American botany, there is a great diversity of plants rich in these compounds, such as açaí, acerola, guarana, camu-camu, maqui, coffee, green mate and chamomile, for example.

Is your company connected to this movement that highlights plant extracts as an up-and-coming ingredient to meet the health and well-being trend? What are the challenges to innovate the portfolio within this concept? Tell us!

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