METHOD FOR PREPARING BEVERAGES BY EXTRACTION EMPLOYING HIGH-PRESSURE PROCESSING (HPP)

Abstract

A method for preparing beverages by extraction, employing high-pressure processing (HPP), for the bulk production of enriched beverages, ready for consumption and with an extended useful life. The method uses high hydrostatic pressures to perform a solid-liquid extraction and/or infusion (e.g. cold infusion) with an improved extraction rate and/or yield, and simultaneously inactivating spoilage and pathogenic micro-organisms to increase its safety and useful life. The method includes placing a mix (8) of solids and liquids in a bag (3) located within a vessel (4) and pressurising same to a pre-set pressure (up to 800 MPa) and maintaining said pressure (10) for a pre-set period of time. The method includes the subsequent depressurisation of the vessel (11) and the removal of the mix from the bag (12), filtering the same under ultra-clean conditions (13), thus obtaining a safe, particle-free beverage, enriched with the extracted compounds of interest.

Claims

1. Method for producing beverages by extraction using High Pressure Processing (HPP), comprising the steps of: a) introducing (8) a mixture of one or several liquids and solids, into a watertight flexible bag (3), which is located inside a high-pressure vessel (4), b) filling (9) the high-pressure vessel with a pressurizing fluid, thus, increasing the pressure inside the vessel wherein the watertight flexible bag prevents direct contact between the pressurizing fluid and the mixture, c) maintaining (10) a predetermined value of pressure inside the vessel during a predetermined period of time, both based on an extraction rate and/or yield desired and an inactivation level of spoilage and/or pathogenic microorganisms that is intended, d) evacuating the pressurizing fluid (11) from the high-pressure vessel, thus, reducing the pressure inside, e) evacuating (12) the mixture from the flexible bag, and f) filtering (13) the mixture evacuated from the flexible bag, and g) obtaining a safe and particle-free beverage, with extracted compounds of interest from the solid or solids.

2. Method according to claim 1, where the steps b), c) and d) are repeated one or more times before step e).

3. Method according to claim 1, where the mixture is introduced into a flexible bag from one or several unprocessed raw material buffer tanks.

4. Method according to claim 1, where the predetermined pressure is between 200 and 800 MPa.

5. Method according to claim 1, where the predetermined holding time under pressure is between 1 s and 59 min.

6. Method according to claim 1, where the solid or the solids of the mixture are microorganisms, plant-based material, algae, or a combination of these.

7. Method according to claim 1, where the liquid or the liquids of the mixture are water, juices, alcoholic solutions, fermented beverages, infused beverages, or a combination of these.

8. Method according to claim 1, where the pressurizing fluid is water, oil, alcohol, or a combination of these.

Description

DESCRIPTION OF THE DRAWINGS

[0030] To complement the description and to aid towards a better understanding of the characteristics of the invention, in accordance with a preferred example of embodiment thereof, a set of drawings is attached as an integral part of said description wherein, with illustrative and non-limiting character, the following has been represented:

[0031] FIG. 1.—Shows a scheme of a preferred embodiment of the device to be used to carry out the method of the invention.

[0032] FIG. 2.—Shows a diagram of a preferred embodiment of the method of the invention.

[0033] FIG. 3.—Shows a graphical representation of coffee extraction (%) (a), and microbiological quality (log CFU/ml) (b) with the results of Example I.

[0034] FIG. 4.—Shows a graphical representation of total soluble protein (μg/ml) extracted from oat solutions with results of the Example II.

[0035] FIG. 5.—Shows a graphical representation of chlorophylls a and b concentration (μg/ml) (a and b, respectively) extracted from microalgae (Chlorella genus) solutions with results of Example III.

[0036] FIG. 6.—Shows a graphical representation of the concentration of total carotenoids (μg/ml) extracted from microalgae (Chlorella genus) solutions with results of Example III.

PREFERRED EMBODIMENT OF THE INVENTION

[0037] FIG. 1 shows a diagram of the preferred device used to carry out the method of the invention.

[0038] The device used comprises a unprocessed raw material buffer tank (1), a flexible bag (3), housed in a high-pressure vessel (4), a filter (6) and a processed material buffer tank (7), being connected one to another by means of a set of ultraclean ducts.

[0039] The unprocessed raw material buffer tank will contain a mixture of one or several liquids and one or several solids, hereinafter referred as “the mixture”.

[0040] The flexible bag (3) is capable to withstand the hydrostatic pressure that will be generated around it, inside the vessel (4), where it is placed. The vessel (4) has two plugs (2, 5) for closing it. The flexible bag (3) is connected to one or both of the plugs (2) by means of a hygienic and watertight connection. The mixture is introduced into the flexible bag (3) through a duct inside the plugs (2) and then the HPP process is carried out.

[0041] Finally, the processed mixture is filtered by using an ultraclean filter (6), to remove the solid particles, and is transferred to the processed beverage buffer tank (7). Afterwards, the obtained final beverage is ready to be packed or furtherly processed.

[0042] FIG. 2 shows a preferable embodiment of the method of the invention. The mixture, contained in the unprocessed raw material buffer tank (1), is introduced (8) by means of a pump through one or both plugs (2) into a flexible bag (3) placed in a high-pressure vessel (4).

[0043] Pressurizing fluid, generally water, is pumped into the high-pressure vessel (4), being filled (9), to pressurize the watertight flexible bag (3). The pressure inside the vessel (4) is maintained (10) a predetermined period of time, allowing for the simultaneous extraction and non-thermal pasteurization to occur, then, the pressurizing fluid is evacuated (11) from the vessel (4), thus, reducing the pressure to atmospheric pressure.

[0044] Following the high-pressure treatment, the mixture is evacuated (12) from the flexible bag (3) through a hygienic valve and is filtered (13) in a clean way to remove solids in suspension and prevent microbial recontamination. The filtered liquid is stored (14) in an ultraclean processed beverage buffer tank (7). The final beverage can be either packed for commercialization or furtherly processed.

EXAMPLES

[0045] The following examples are provided by way of illustration of embodiments of the invention and are not intended to limit or constrain the invention. As indicated above, applying high pressure to a solid-liquid mixture followed by subsequent filtration can extract compounds of interest from said solid and inactivate microorganisms simultaneously, delivering an enriched beverage with improved microbiological quality.

Example I

[0046] Eight samples of cold-brew coffee, prepared by mixing roasted grinded coffee (Arabica variety) with cold water (5 g/100 ml), were treated as follows: [0047] Samples #1 to #5. Control samples (no HPP) filtered after 1, 3, 5, 7 and 9 h of standard cold brewing at 4° C. [0048] Sample #6. Pressurized sample of coffee (600 MPa/3 min/4° C.) filtered immediately after HPP [0049] Sample #7. Pressurized sample of coffee (two consecutive cycles at 600 MPa/1.5 min/4° C.) filtered immediately after HPP [0050] Sample #8. Pressurized sample of coffee (785 MPa/5 min/4° C.) filtered immediately after HPP

[0051] Samples #6 to #8 were subjected to HPP in a Hiperbaric 525 Bulk unit and hygienically filtered to remove solid coffee particles. The total process time was less than 1 hour (including all HPP steps and filtering).

[0052] Extraction (%) was determined for every sample (#1 to #8) and total aerobic counts were determined in HPP samples (#6 to #8) and two control samples (#1 and #5). Results are shown in FIG. 3a (% extraction) and 3b (total aerobic counts), wherein HPP samples (#6 to #8) show counts below a detection limit of 1 CFU/ml.

[0053] As can be seen, extraction (rate and yield) and microbiological quality are improved in HPP samples (#6 to #8). Generally, the extraction is equal or better than in the best control sample, without using HPP, i.e. control sample (#5) filtered after 9 h of standard cold brewing at 4° C.

Example II

[0054] Six samples of an oat solution, prepared by mixing oats with cold water (15 g/100 ml), were treated as follows: [0055] Samples #1 to #4. Control samples (no HPP) filtered after 3, 5, 7 and 9 h of standard cold brewing at 4° C. [0056] Sample #5. Pressurized sample (600 MPa/2 min/4° C.) filtered immediately after HPP [0057] Sample #6. Pressurized sample (two consecutive cycles at 600 MPa/1.5 min/4° C.) filtered immediately after HPP

[0058] Samples #5 and #6 were subjected to HPP in a Hiperbaric 525 Bulk unit and hygienically filtered to remove solid oats in suspension. Total soluble protein was determined for every sample (#1 to #6). Results are shown in FIG. 4.

[0059] As can be seen, total soluble protein extraction is improved significantly in HPP samples (#5 and #6). Shelf-life of these samples is extended from a few days to more than one month.

Example III

[0060] Six samples of a microalgae solution (Chlorella genus), prepared by mixing powdered microalgae with water (5 g/100 mL), were treated as follows: [0061] Samples #1 to #4. Control samples (no HPP) filtered after 3, 5, 7 and 9 h of standard cold brewing at 4° C. [0062] Sample #5. Pressurized sample (600 MPa/2 min/4° C.) filtered immediately after HPP [0063] Sample #6. Pressurized sample (two consecutive cycles at 600 MPa/1.5 min/4° C.) filtered immediately after HPP

[0064] Samples #5 and #6 were subjected to HPP in a Hiperbaric 525 Bulk unit and hygienically filtered to remove microalgae in suspension. Chlorophyll a and b and total carotenoid concentrations were determined for every sample (#1 to #6).

[0065] Results are shown in FIGS. 5a and 5b (chlorophylls a and b concentration, respectively) and FIG. 6 (total carotenoid concentration).

[0066] As can be seen, chlorophyll a and b and total carotenoid extractions are improved and/or enhanced in HPP samples (#5 and #6). Shelf-life of these samples is increased by more than 10 times compared to control samples.