Process for the preparation of concentrated water-soluble extracts

Abstract

The process for the preparation of concentrated water-soluble extracts, comprises the following phases of: e) provision of at least one plant substrate; f) extraction of at least one extract from the plant substrate; c) concentration of the at least one extract comprising the steps of: c1) subjecting the extract to controlled vacuum conditions; c2) applying a temperature below 65 °C to the extract to obtain a concentrated extract; the phase of concentration being earned out until a residual water activity value of the concentrated extract comprised between 0.500 aW and 0.100 aW is achieved.

Description

[0001] PROCESS FOR THE PREPARATION OF CONCENTRATED WATER- SOLUBLE EXTRACTS

[0002] Technical Field

[0003] The present invention relates to a process for the preparation of concentrated water-soluble extracts.

[0004] Background Art

[0005] As is known, water-soluble plant extracts are widely used in nutraceuticals and cosmetics as functional ingredients capable of effectively conveying active ingredients useful for the functionality of the final product.

[0006] It is of paramount importance, therefore, that they have characteristics of stability, solubility, functionality, reproducibility and use that make them suitable for the desired use.

[0007] In this regard, it is known that the extracts are obtained from plant substrates undergoing extraction.

[0008] Extraction is generally carried out by various techniques such as maceration, countercurrent pressure Solid / Liquid extraction or ultrasonic extraction.

[0009] The type of extraction, as well as the extractive solution used in the latter, varies depending on the type and on the chemical / physical characteristics of the active ingredients required in the finished product and on the appearance and solubility characteristics that the extract must have.

[0010] All of these methods do, however, have some drawbacks, including the fact that they do not allow for precise predetermined drug / extract concentration ratios.

[0011] Added to this is the fact that these methods greatly affect the quality of the extract obtained in terms of stability, water solubility and bioavailability.

[0012] To fix at least some of these drawbacks, the extracts obtained are subsequently added with preservatives and / or carriers and passive stabilizers such as, e.g., maltodextrins, glycols or silicates which, when formulated with other components, greatly affect the rheology of the finished product in which the extract is placed.

[0013] This also greatly impacts the regulatory context of both the extract and the finished product, significantly complicating the operations required for regulation and, consequently, marketing.

[0014] The invention that is covered by this patent application differs markedly and significantly from the documents which are known to the state of the art.

[0015] Specifically, document WO 2023 / 233175 Al describes a phyto-complex extraction process aimed at obtaining solid or liquid products, but it does not specifically provide for or control parameters such as the water activity (aW) of the concentrated extract, nor does it employ the synergistic combination of controlled vacuum and temperature below 65 °C aimed at producing a liquid water-soluble extract with high stability. The process of WO 2023 / 233175 is not capable of obtaining liquid extracts with properties similar to those of anhydrous substances.

[0016] Document US 2023 / 263202 Al focuses on purification methods for extracts containing flavonoids, without describing an integrated extraction-concentration- dealcolation process aimed at obtaining a liquid water-soluble product with residual water content of between 0.500 aW and 0.100 aW. In addition, US 2023 / 263202 is limited to chemical operations on the extract, thus neglecting the physical and rheological effects related to water content and preservative-free stability.

[0017] Document PL 228580 relates to the production of plant extracts, but neither teaches nor claims precise parameters related to vacuum pressure, nor a controlled temperature below 65 °C, nor even the achievement of specific water activity values. In addition, no guidance emerges on the use of solvent combinations such as water, glycerin, glycols, alcohols or glucides depending on their inevaporability.

[0018] Finally, US 2021 / 283208 describes extract-based cosmetic formulations, but not a process for producing the extracts themselves.

[0019] Description of the Invention

[0020] The main aim of the present invention is to devise a process for the preparation of a concentrated water-soluble extract which allows the biologically active components contained therein to remain unaltered.

[0021] One object of the present invention is to devise a process for the preparation of a concentrated water-soluble extract which allows obtaining extracts with a guaranteed concentration ratio.

[0022] Another object of the present invention is to devise a process for the preparation of a concentrated water-soluble extract which allows the aforementioned drawbacks of the prior art to be overcome within the framework of a simple, rational, easy and effective to use, as well as inexpensive solution.

[0023] The aforementioned objects are achieved by this process for the preparation of a concentrated water-soluble extract having the characteristics of claim 1.

[0024] Embodiments of the Invention

[0025] The present invention relates to a process for the preparation of concentrated water-soluble extracts.

[0026] According to the invention, the process comprises the following phases of: a) provision of at least one plant substrate; b) extraction of at least one extract from the plant substrate; c) concentration of the extract comprising the steps of: cl) subjecting the extract to controlled vacuum conditions; c2) applying a temperature below 65 °C to the extract to obtain a concentrated extract; wherein the phase of concentration is carried out until a residual water activity value of the concentrated extract comprised between 0.500 aW and 0.100 aW is achieved.

[0027] Advantageously, the plant substrate is selected from the list comprising: flowers, leaves, roots, fruits.

[0028] It cannot be ruled out from the present disclosure that the provision phase involves the use of a plurality of different plant substrates.

[0029] This means that the plant substrates can be obtained from different plant species or from the same plant species, but from different parts of the same (e.g. leaves and flowers).

[0030] Preferably, the provision phase of the plant substrate comprises a preliminary phase of micronization of the plant substrate.

[0031] Specifically, the micronized plant substrate is subjected to homogenization before the extraction phase.

[0032] In accordance with a preferred embodiment of the invention, the plant substrate is subjected to a homogenization phase, preliminary to the extraction phase.

[0033] The aforementioned homogenization phase is of the mechanical type. In detail, the phrasing “homogenization phase of the mechanical type” refers to homogenization carried out by high-speed stirring with paddles or turbines, (high-pressure) piston homogenizers, colloidal mills or combined ultrasonic and stirring systems.

[0034] Advantageously, the homogenization phase is carried out by dipping the plant substrate in an extraction mixture.

[0035] The extraction mixture comprises at least one of: water, glycols, glycerin, alcohols, polyhydric alcohols, glucides or combinations thereof.

[0036] In more detail, by way of example, such combinations comprise: water and glycols and / or glycerin; water, alcohols, glycols and / or glycerin; alcohols, polyhydric alcohols, water; water and glucides.

[0037] It cannot be ruled out from the scope of this disclosure that the homogenization phase may be performed without subjecting the plant substrate to the micronization phase.

[0038] Next, the plant substrate is subjected to the extraction phase.

[0039] In detail, the extraction phase is carried out according to different extraction techniques which vary depending on the type of plant substrate.

[0040] For this purpose, the extraction phase is carried out through at least one of: ultrasonic extraction, pressure, squeezing, grinding, extrusion, centrifugation or assisted filtration.

[0041] It should be pointed out that it cannot be ruled out from the scope of this disclosure that the extraction phase may be performed by using one of the above techniques in combination with enzymes and / or pH modifying agents.

[0042] The extraction phase is performed by using the extraction mixture detailed above. It should be pointed out that the above solvent combinations can be used synergistically with one or more of the above extraction techniques depending on the type of starting plant substrate.

[0043] When alcohols are present, the process in accordance with the present invention comprises at least one phase of dealcolation of the extract.

[0044] In detail, the extraction mixture also serves as an active carrier, thus promoting encapsulation and conveying of polar active ingredients in a medium-polarity extract.

[0045] In even more detail, the extraction mixture, serving as an active carrier, conveys high-polarity compounds through a cold-operated concentration phase under low pressure and temperature-controlled conditions.

[0046] In fact, the use of the aforementioned combinations of solvents makes it possible to obtain concentrated extracts with a guaranteed concentration ratio and related to the amount of inevaporable solvent used, which is present from the first phases of the process in accordance with the present invention.

[0047] This inevaporable component does not serve as a mere passive medium, but plays a functional role in conveying and encapsulating high-polarity active ingredients, thus contributing to the stability of the final extract.

[0048] In fact, according to the present invention, the fact that the extraction phase is carried out mechanically and / or by ultrasound, starting from a previously micronized and homogenized plant substrate, allows maximizing extraction efficiency and ensuring optimal contact between substrate and extraction mixture already containing the active carrier.

[0049] In detail, the fact that the inevaporable solvent may be present from the homogenization phase is crucial because the latter has an active role in the extraction phase.

[0050] It cannot be ruled out from the scope of this disclosure that the extraction phase may comprise a filtration step which is necessary to carry out a solid / liquid separation between the plant substrate and the extraction mixture.

[0051] It cannot also be ruled out that the extract obtained from the extraction phase is subjected to tangential ultrafiltration.

[0052] Advantageously, tangential ultrafiltration is carried out by means of ceramic membrane, with a molecular cut-off equal to or less than 0.1 micron.

[0053] Next, once the extraction phase is completed, the obtained extract is then subjected to the concentration phase.

[0054] During this phase, controlled vacuum conditions comprise pressure values comprised between -900 mBar and -1950 mBar.

[0055] In accordance with a preferred embodiment of the process according to the invention, the pressure values are comprised between -750 mBar and -1800 mBar.

[0056] At the same time, the temperature is comprised between 20°C and 60°C. Preferably, the temperature is comprised between 25°C and 55°C.

[0057] The low level of free water that is achieved according to the teachings of the process in accordance with the present invention allows for an environment in which the proliferation of mold and bacteria is hindered, thus enabling selfpreservation.

[0058] This allows avoiding the use of preservative and / or acidifying additives, since the extract obtained is substantially anhydrous.

[0059] In other words, the concentrated extract obtained from the process in accordance with the present invention is in liquid form but, thanks to the synergistic combination of the controlled vacuum conditions with pressure values comprised between -750 mBar and -1800 mBar, it has chemical and physical properties of the pulverulent extracts.

[0060] It cannot be ruled out from the scope of this disclosure that the concentration phase may comprise cold distillation under controlled vacuum conditions aimed at the selective removal of low-boiling solvents.

[0061] Example 1: Process for the preparation of concentrated water-soluble extracts from valerian, passionflower tops and hop flowers.

[0062] Table 1

[0063] The provision phase is carried out by mixing the dried plant substrates together, namely valerian, passionflower and hops with rehydration water. By way of example, a plant substrate value of 750 g is obtained, which is then mixed with the extractive mixture, i.e., water, glycerin and alcohol for a total of 700 g.

[0064] At this point, the extraction phase and the filtration step are performed so that the plant substrate is separated from the extract (quantifiable at about 1375 g).

[0065] This is followed by the extract concentration phase.

[0066] In detail, the synergistic combination of temperatures comprised between 25 °C and 55°C with pressure values of between -750 mBar and -1800 mBar makes it possible to obtain a concentrated extract in an amount of 100 g.

[0067] During this phase, in fact, low-boiling solvents (ethanol and water) are removed due to the low pressure applied until a concentrate is obtained which will correspond to the amount of initially inserted glycerin (100 g).

[0068] This allows obtaining a concentrated extract approximately fourteen times that of the starting extract and having a plant substrate to concentrated extract ratio of 7.5: 1.

[0069] It has in practice been ascertained that the described invention achieves the intended objects.

[0070] In particular, the fact is emphasized that the special expedient of providing for the synergistic combination, during the concentration phase, of temperatures of between 25°C and 55°C with pressure values of between -750 mBar and -1800 mBar makes it possible to obtain a concentrated extract having high concentration of active substances and complete water solubility.

[0071] In addition, this combination of operating conditions allows obtaining high stability of the extracted components thanks to low residual water.

[0072] This characteristic makes it a concentrated extract in liquid form, the chemical / physical behavior of which is quite comparable to anhydrous pulverulent substances.

[0073] In addition, this characteristic allows it to be used without the need to add preservatives and stabilizers.

[0074] In light of the above, the invention is characterized by: - the synergistic use of specific extraction techniques and mixtures of functional solvents (water, glycerin, glycols, etc.); a concentration phase carried out under controlled vacuum at a temperature below 65 °C, the controlled achievement of a water activity value of between 0.500 and 0.100 aW, obtaining a self-preserved liquid water-soluble extract with no added preservatives and with characteristics comparable to those of anhydrous powders.

Claims

CLAIMS1) Process for the preparation of concentrated water-soluble extracts, comprising the following phases of: c) provision of at least one plant substrate; d) extraction of at least one extract from said plant substrate; c) concentration of said at least one extract comprising the steps of: ci) subjecting said extract to controlled vacuum conditions;C2) applying a temperature below 65 °C to said extract to obtain a concentrated extract; said phase of concentration being carried out until a residual water activity value of said concentrated extract comprised between 0.500 aW and 0.100 aW is achieved.2) Process according to claim 1, characterized by the fact that said controlled vacuum conditions comprise pressure values comprised between -900 mBar and -1950 mBar.3) Process according to one or more of the preceding claims, characterized by the fact that said pressure values are comprised between -750 mBar and -1800 mBar.4) Process according to one or more of the preceding claims, characterized by the fact that said temperature is comprised between 20°C and 60°C.5) Process according to one or more of the preceding claims, characterized by the fact that said temperature is comprised between 25°C and 55°C.6) Process according to one or more of the preceding claims, characterized by the fact that said phase of extraction is carried out through at least one of: ultrasonic extraction, pressure, squeezing, grinding, extrusion, centrifugation or assisted filtration.7) Process according to one or more of the preceding claims, characterized by the fact that said phase of extraction comprises the use of at least one extraction mixture comprising at least one of: water, glycols, glycerin, alcohols, polyhydric alcohols, glucides or mixtures thereof.8) Process according to one or more of the preceding claims, characterized bythe fact that it comprises at least one phase of dealcolation of said extract.9) Process according to one or more of the preceding claims, characterized by the fact that said plant substrate is selected from the list comprising: flowers, leaves, roots, fruits.10) Process according to one or more of the preceding claims, characterized by the fact that said provision phase of said plant substrate comprises a preliminary phase of micronization of said plant substrate.11) Process according to one or more of the preceding claims, characterized by the fact that said micronized plant substrate is subjected to a phase of homogenization before said extraction phase.12) Process according to one or more of the preceding claims, characterized by the fact that said homogenization phase is of the mechanical type.13) Process according to one or more of the preceding claims, characterized by the fact that said homogenization phase is carried out through the use of an extraction mixture comprising at least one of: water, glycols, glycerin, alcohols, polyhydric alcohols, glucides or mixture thereof.14) Process according to one or more of the preceding claims, characterized by the fact that said extract obtained from said extraction phase is subjected to tangential ultrafiltration.15) Process according to claim 14, characterized by the fact that said tangential ultrafiltration is carried out by means of ceramic membrane, having a molecular cut-off equal to or less than 0.2 micron.16) Process according to one or more of the preceding claims, characterized by the fact that said concentration phase comprises cold distillation under controlled vacuum conditions.17) Concentrated extract obtained by the process according to one or more of the preceding claims, having a residual water activity value of said concentrated extract comprised between 0.500 aW and 0.100 aW.

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