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Zawartość zarchiwizowana w dniu 2024-05-29

Highly selective and environmentally friendly fruit extraction using supercritical fluids technology

Final Report Summary - EXTRANAT (Highly selective and environmentally friendly fruit extraction using supercritical fluids technology)

The project EXTRANAT brought together the necessity of the vegetable processed producers to find a way to reuse their wastes and the will of the food additives, cosmetic and pharmaceutical producers to obtain natural and healthy products from a cheaper source.

In the last decades, the food science and technology have developed new products in a safer way, improving the quality and the availability of the final products, and providing thus a higher added value for the consumers. At the same time, the consumers have greatly increased the demand for natural obtained products.

On the other hand, the environmental protection and sustainable development have reached the highest possible levels of interest among citizens, not only throughout Europe but also all around the world.

Most of the food and agricultural industry organic residues are currently disposed or used on a low technological and economical level. Two of the most popular reutilisations of these wastes are the production of compost or biomass fuels. However, these two possibilities do not yield economic benefits for the vegetable producers, they only try to solve the environmental problem of wastes disposals.

In order to generate the desired economic advantages, it is necessary to look closely to the composition of the wastes to be revalorised. These subproducts and wastes are generally very rich in bioactive, mainly antioxidant and anticarcinogenic substances, which are considered to be responsible for the health promoting properties of the dietary habits in which fruit and vegetables are relevant ingredients.

Supercritical fluid extraction may be regarded as a healthy alternative to traditional extraction methods. It is one of the most important new applications of high-pressure processes. It has become a successful technique for the separation of compounds from natural and synthetic sources and widely accepted for extraction, purification, recrystallisation, and fractionation operations in many industries. Other possible applications are precision cleaning of semiconductors and other electronic equipment, textile dyeing and dry cleaning, impregnation (wood, polymers, and catalysts), coatings and varnishing, etc.

Furthermore, supercritical fluid extraction is far more efficient than traditional solvent separation methods. Supercritical fluids are indeed selective, thus providing the high purity and product concentrations. Extraction is efficient at modest operating temperatures, for example, at less than 50 degrees Celsius, thus ensuring maximum product stability and quality.

EXTRANAT aimed to develop and implemented a highly selective and environmentally friendly method to extract compounds with anti-oxidant activity from fruit and vegetable waste, based upon the Supercritical fluid extraction (SFE) technique.

The main objectives of the project for this first year were:
- to define functional components and their availability in vegetable wastes;
- to study SFE applied to the food industry;
- to select the kind of waste to be used during the project;
- to design the pilot plant in which the method will be tested.

The main objectives of the project second year were:
- to end the construction of the pilot plant, specifying as much as possible the design, in order to minimise the future actions of final tuning;
- to run laboratory tests to assure characterise as much as possible the extracts;
- to continue with the dissemination and publicity activities.

Since the main target of the project is the isolation and production of an extract from vegetal wastes with functional or nutraceutical properties, the initial action to proceed in the selection of the wastes to be used in the project was the definition of a criteria for this choice:
- the expected behaviour of the raw material against SFE;
- the expected activity and possible use of the compounds of the materials (antioxidant, colorant, etc.)
- the content of the compound of interest in the raw material;
- the aspect of the material (roots, stem, grape, pomace).

The following species were considered in the definition of the set of raw materials, all of them related to some of the partners activity:
- strawberry (Fragaria vesca)
- apricot (Prunus armeniaca)
grape (Vitis vinifera)
pepper (Capsicum SPP)
- tomato (Licopersicon escolentum)
carrot (Daucus carrota).

In the definition of the criteria, the properties of active compounds contained in the selected vegetal wastes were considered. These properties should be useful from an industrial point of view. The considered active compounds, which could be extracted, were:
- Terpenes and tocopherols: These compounds are usually present in green and coloured vegetables. The main useful activity in the industry is their high antioxidant activity. On the other hand, they could act as colorants, but they could be neither competitive nor profitable.
- Flavonoids and polyphenols: The main activity related with flavonoids and polyphenols is the antioxidant activity. Their tendency to act as chelating agents could be used as a functional property and it is suspected them to have anticarcinogenic activity.

The project was structured into eight Work packages (WPs), as follows:
WP 1: Specifications and needs
WP 2: Selection of samples and laboratory tests
WP 3: Design of the pilot plant
WP 4: Manufacturing process establishment at laboratory scale
WP 5: SME implementation. In situ measurements and final validation
WP 6: Production test
WP 7: Exploitation and dissemination
WP 8: Project management.

The results obtained in the project could be used to estimate the application of the process to other vegetable species. In order to evaluate the efficiency and the quality of the extraction, several methods to measure antioxidant capabilities were studied. Most of these assays are quite well known such as the Oxygen radical absorbance capacity assay (ORAC), the Folin-Cicolteau (F-C) method the Trolox equivalent antioxidant capacity assay (TEAC), the TRAP assay, Total oxidant scavening capacity (TOSC), the Chemiluminescence (CL), Low-density lipoprotein oxidation (LDL), Croton or beta-carotene bleaching by LOO, Ferric reducing antioxidant power (FRAP), Copper reduction assay' (CUPRC), DPPH…Once these methods were confronted with the samples chosen and their characteristics, three of them were chosen to be used during the project: F-C, DPPH and TEAC.

Through the experiments carried out in a SFE plant at laboratory level, the consortium was able to decide the flow chart of the final process, including pre-treatments and the optimum parameters (temperature, flow rate, pressure…) to be used during the extraction. With this design, the pilot plant has been constructed in CARTIF's facilities and after its finalisation, it has been finally transported and mounted in the Matarromera's installations and the process finally optimised.

The achievements arisen from the EXTRANAT project will mean potential benefits to the different SMEs involved. Within the consortium are represented the different market areas that could be interested in the developments carried out in EXTRANAT. There are two vegetable producers that would benefit of the great revalorisation of their wastes: Copaisan and Matarromera. There is a company with importance in the building of production plants that may include SFE, Enviplan. Aldivia has expertise in the use of antioxidant compounds in the cosmetic industry. The compounds yielded from the EXTRANAT process will have some applications in the food additive industry and in this market sector GRADIENS will apply their expertise. The pharmacological applications for the antioxidant compounds were studied by EXXENTIA.

The other industry participating in EXTRANAT is Helios. This big company has joined with a twofold interest. On one hand, as a canned vegetable producer it will also see how some of its wastes develop a high revalorisation, and in the other if a food additive application is found, Helios may commercially exploit that result.

During the whole project the main efforts have been technical and therefore the biggest work charges were appointed to the RTD performer. Anyhow, these technical developments were in every moment guided from the group of SME towards exploitable results that may turn in benefits for the enterprises.