Method and device for extracting oil from oily fruit

Abstract

A method, apparatus and system for extracting oil from an oily fruit paste by exposing the oily fruit paste to a vacuum.

Description

[0001] This application is a divisional application of PCT patent application PCT / EP2018 / 075674 (international application date is September 21, 2018, priority date is September 22, 2017, Chinese national application number is 201880075466.4, and the name of the invention is "Method and device for extracting oil from oily fruits") which entered the Chinese national phase on May 21, 2020. Technical Field

[0002] The invention relates to a method for extracting oil from oily fruits by applying a vacuum to a paste-like preparation, thereby replacing the conventional blending step. For this purpose, a vacuum extractor is disclosed. Background Art

[0003] The process of producing oil from oleaginous fruits using physical means has been known throughout human history, and current technology is based on principles similar to those used for hundreds of years, regardless of mechanization and improved tools to reduce labor costs and time.

[0004] One of the major changes in the olive oil production process, or any other oil from oleaginous fruit, has been caused by the introduction of the use of centrifugal force to separate the oil from the pulp after blending. The use of a centrifuge for the separation step makes it possible to use a continuous system for oil production.

[0005] Briefly, in the prior art, the process consists of the following steps: debranching, defoliation and washing of the raw material, i.e. the freshly harvested oleaginous fruit. In the following, the production process of olive oil will be described in more detail. In order to obtain the oil, a series of steps are applied, which may consist of: crushing / pitting, blending, pressing / centrifugation and vertical decantation / centrifugation, etc. In the following, the process is described in more detail in the case where the oleaginous fruit is an olive.

[0006] Prepare the ingredients take over In the prior art, the raw materials must arrive at the extraction equipment in good hygienic conditions and be packaged in appropriate containers.

[0007] clean In general, all prior art systems for olive oil production are designed to ensure that the olives reach the mill without dirt, in order to prevent wear on the machinery. Cleaning can be done dry, or can be supplemented by washing the olives with water, the latter being the more widely used method. The operations usually performed are the following: 1- Debranching: It is especially useful when there are buds and branches together with the olives. Continuous mechanical harvesting systems have this operation integrated, so in this case it is not incorporated into the oil production equipment. The operation is carried out using rollers on which the branches are conveyed. The olives fall through the gaps between these rollers.

[0008] 2- Defoliation: It is done by suction or aeration.

[0009] 3-Washing: Washing generally consists of two steps. In the first step, the olives are washed with water that is constantly circulating. In the second step, the washed olives are rinsed with a final spray of water to complete the washing process, allowing for a continuous change of water in the washing machine.

[0010] Preparation of paste The purpose of the crushing operation is to break up the tissue in which the oily substance is embedded and it must be done as smoothly as possible. During grinding, some oil droplets are released.

[0011] This operation can be performed using several types of mills. The main types are stone mills or metal crushers. Stone mills are usually truncated cone or cylindrical in shape. The most commonly used metal crusher is the hammer crusher. Usually, they have fixed or mobile hammers, 5 to 7 mm screens, and rotate between 1800 and 2400 rpm. Another type of crusher is the disc crusher, in which the olives are completely crushed in a toothed disc crusher using a system with a rotating disc acting on a stationary disc. The olives fed into this type of crusher are thrown away from the center and crushed when they encounter the toothed discs, and are driven by a motor.

[0012] The pitter is operated by a screw feed assembly that directs the olives into a special vessel with perforations. A rotating mixer moves the olives towards the periphery where the pulp is separated from the stones and discharged intact and clean at the end opposite to the feed side. The pulp passes through the holes of the basket and falls into a hopper below. The screw then moves the product from the hopper to a pump that feeds the mixer.

[0013] Mills have the disadvantage of incorporating large amounts of air when rotating at such high speeds and producing an oil-in-water emulsion, furthermore leaving large sized fragments of mesocarp cell tissue.

[0014] Grinding the olives results in only between 40-50% of the oil droplets dispersed in the paste having a diameter higher than 30 μm. To achieve continuous phase separation, the droplet diameter should be greater than 30 μm (Khlif M., Rekik H., Arous N. (2003). La cadenacontinua en la extracción de aceite de oliva in Túnez: modalidades operativa (Continuous chain of olive oil extraction in Tunisia: operating modes). Olivae. 96: 38-42). This is related to the disclosure of Di Giovacchino, L. "Olive Oil Extraction by Pressing, Centrifugation and Percolation: Effect of Extraction Methods on Oil Yields", Olivae, vol. 36, p 14-30 (1991) that the smaller the size of the oil droplets, the higher their stability, making them more difficult to reorganize into larger droplets.

[0015] The purpose of the agitation treatment is to agglomerate the dispersed and emulsified liquid oil droplets in the milled paste in the relevant successive stages, so as to facilitate and increase the solid-liquid separation in the following production operations. It also produces lacerations of the outer cells in the whole tissue fragments remaining in the mill, releasing a certain percentage of the oil in the interior of the cell vacuoles. Usually, this is carried out at a temperature range of 25 to 30°C, which favors the destruction of the cells by enzymatic action.

[0016] The walls and blades in the mixer are usually made of stainless steel, and the mixing should be continued long enough to obtain the highest possible percentage of free oil. The best mixing conditions are a final paste temperature of 25 to 30°C and a speed of 8 to 14 rpm during 45 to 3 hours.

[0017] The recently broken / pitted olive paste does not have the optimal temperature for maximum coalescence of the released oil droplets, wasting 50% of the time for mixing the olive paste to reach the ideal temperature for proper quality. This can lead to mixing times of up to 2 hours when the recommended time for 'premium' quality extra virgin olive oil (EVOO) is 1 hour and even less than 50 minutes. These mixing times (combined with the large air volume incorporated into the paste in the mill and the optimal temperature) lead to the action of peroxidases and polyphenol oxidases, thus causing oxidation of the paste and reduction of the phenolic fraction of the oil.

[0018] It is worth clarifying that after this step, finer particles will still be present in the oil and will be eliminated in later steps in the process such as gravity settling or filtration.

[0019] Separation of solid and liquid phases Traditionally, pressing using a hydraulic press is the most widely used method for separating the liquid and solid phases. During pressing, the prepared paste is placed in a thin layer on mats, which are placed on top of each other and then subjected to pressure. Today, such methods are mostly obsolete.

[0020] Centrifugation has largely replaced pressing. Currently, centrifugation causes the mixed olive paste to phase separate into a solid phase and a liquid phase. Such separation is carried out in a decanter (called a horizontal centrifuge) whose rotor spins at about 3000 rpm.

[0021] Three-phase or three-outlet system This is the name given to a centrifuge system equipped with a decanter with three separate product outlets, which separate during centrifugation and consist essentially of oil, waste water and olive cake.

[0022] The system uses added warm water to the paste before it enters the decanter in order to fluidize it and achieve better separation of the liquid phase, oil, wastewater or vegetable water.

[0023] Two-phase or two-outlet system This is the name given to a system with a decanter with two separate product outlets, oil and pomace (olive cake plus vegetable water).

[0024] Unlike the three-phase system, this system does not use added water and does not produce plant water. The system significantly reduces the effluent and pollutant load in the oil production facility. Instead, wet pomace is obtained, which is a solid by-product with a relatively high humidity.

[0025] Vibratory filtration is a step used to retain coarse particles carried with the oil at the outlet of the decanter. It has a flat horizontally vibrating, slightly inclined filter screen where the oil passing through the screen is collected.

[0026] A third method of separating the solid and liquid phases is the Sinolea process. In this process, rows of metal discs or plates are dipped into the paste; the oil preferentially wets and sticks to the metal and is removed with a scraper in a continuous process. It is based on the different surface tensions of vegetable water and oil, these different physical behaviors allow the olive oil to adhere to the steel sheet, while the other two phases remain behind.

[0027] Sinolea works by continuously introducing hundreds of steel blades into the paste, thus extracting the olive oil. The process is not completely efficient, and a large amount of oil remains in the paste, so the remaining paste must be processed through standard modern methods (such as industrial decanters).

[0028] Separation of liquid phase Liquid phase separation can be performed using different methods, among which are gravity separation and centrifugation.

[0029] Gravity separation is an old method of separating oil and vegetable water based on the different densities between the two. This is done by continuous feeding through several interconnected vessels.

[0030] Centrifugation also separates the different phases (water and tissue left by the decanter) based on their different densities, causing gravity to increase at a speed of 6500 rpm. This process emulsifies air into the oil, affecting its preservation through oxidation.

[0031] The centrifugation process leaves behind traces of suspended water and plant tissues, which slowly settle under the action of gravity. To facilitate this effect, the centrifuged products are stored at higher temperatures and regular sediment removal is performed. Water and tissues contain dissolved sugars, which are ideal substrates for fermentation, transferring undesirable flavors to the oil. To prevent this, products are used to increase precipitation, but no significant results have been obtained. These oils are stored with a certain amount of humidity and impurities; these cause the oils to settle, ferment and fill them with undesirable odors and flavors. Therefore, the tanks in which the oils are stored must have a conical bottom to allow proper purification.

[0032] storage The oil storage tank is the place where the filtered or unfiltered oil is kept until it is graded or shipped, generally in stainless steel tanks. The oil storage tank must have walls and roof that are isolated from the outside temperature and must not transfer odors into the oil. It must also have a conditioning system to maintain a constant temperature of about 15-18°C, it should not produce odors and have low luminosity.

[0033] Olive Oil Quality All foods must meet certain organoleptic characteristics in order to be eaten. In particular, olive oil is divided into olive oil, virgin olive oil and extra virgin olive oil according to its quality. The two main characteristics that determine the quality of the oil are the acidity value and the peroxide value. These characteristics are directly affected by the methods used to extract and preserve the olive oil. Mention should also be made of the quality of the raw material, the phytosanitary conditions, the harvesting system (olives without cracks or bruises) and the time between harvesting and extraction (if it is too long, the final product will deteriorate).

[0034] It is common practice at some facilities to treat olives when they are frostbitten. This is freezing that causes mechanical rupture of the oily fruit tissue, thus producing cell rupture through freezing and subsequent dehydration. As a result, the yield increases, but the quality of the olive oil decreases significantly.

[0035] Rancidity of fats and oils is a natural process by which their composition changes over time, which causes, among other things, changes in their organoleptic properties, ie, in their flavor. In particular, the flavor of oils that have undergone intensive oxidation processes is called rancid.

[0036] - In hydrolytic rancidity, the lipase present in the olive pit catalyzes the hydrolysis of glycerides, producing free fatty acids and partial glycerides. As a result, the acidity in the olive oil is increased. As disclosed in Richardson T., Hylsop D. (2001). Chapter 6 In "Quimica de Alimentos" (Chapter 6 in "Food Chemistry") Fennema O. Ed Acribia; Belitz HD, Grosch W. (1997). Chapter 2 In "Quimica de Alimentos" (Chapter 2 in "Food Chemistry") 2 ° Ed Acribia, Zaragoza and in Quirasco BM, Lopez-Mungia AC (2006). Chapter 5 In "Quimica de Alimentos" (Chapter 2 in "Food Chemistry") Badui DS, 4 ° Ed Pearson Education., during the acquisition of the oil, the hydrolysis reaction occurs in the oil-water interface and increases exponentially during the emulsification of the olive paste.

[0037] Acidity is expressed as grams of oleic acid per 100 grams of olive oil, and it is called the acidity percentage. Free fatty acids are essentially evaluated using this percentage, and it is not only related to the characteristics of the raw materials used, but also to the treatment method. Thus, for example, the quality of olive oil is directly related to the degree of hydrolysis of the triglyceride component. As this degree increases, the amount of free fatty acids increases, thereby increasing its acidity, proportionally impairing the quality of the olive oil.

[0038] Oxidative rancidity is due to the oxidation of double bonds in unsaturated fatty acids to form peroxides or hydroperoxides, which subsequently polymerize and decompose to form aldehydes, ketones and lower molecular weight acids. This process can be accelerated in the presence of oxygen, light, heat, moisture, other free fatty acids and certain inorganic catalysts (such as iron and copper salts).

[0039] Oxidized fats have an unpleasant flavor and odor, and can be slightly toxic to some individuals.

[0040] Oxidative rancidity also destroys fat-soluble and water-soluble natural antioxidants. These are the main components of olive oil that provide health benefits. Among them are the following: tocopherols, carotenoids, phenolic moieties, etc.

[0041] The most important phenolic fractions of olives are represented by: -Benzyl alcohols: 3,4-dihydroxyphenylethanol, hydroxytyrosol, p-hydroxyphenylethanol and tyrosol -Flavonoids: anthocyanidins, rutin and lethidin-7-glucoside.

[0042] -Carotenoids: oleuropein, dimethyloleuropein, ligustrin and velcocoside.

[0043] - Phenolic acid: olefinic acid.

[0044] The main role of antioxidants is to prevent, delay and / or reduce reactions that lead to oxidation of biological substrates (proteins, lipids and nucleic acids).

[0045] An important parameter for determining the quality of olive oil is through UV spectroscopy. Absorbance measurements are performed at different wavelengths. This analysis provides indications about the quality of a particular oil and its state of preservation. It can also be used to detect abnormal components in virgin olive oil as well as peroxide values ​​and the main oxidation stages in olive oil.

[0046] During the extraction and processing of oil from oily fruits, the oil will be exposed to oxygen, resulting in oxidation. Oxidation of the oil results in the loss of volatile aromas and beneficial micronutrients such as polyphenols (antioxidants). In addition, oxidation will lead to adverse changes in the flavor and therefore the quality and flavor profile of the oil. Due to the negative effects of exposure to oxygen and the resulting oxidation on the oil, it is known in the art to operate the mixing or milling process under limited or mild vacuum to limit exposure to oxygen.

[0047] Migliorini M. et al. (2008). “Influence of operating conditions of malaxation on the quality of extra virgin olive oil”, J. Agric. Food Chem, v. 56, p. 10048-10055 disclose how olive oil quality is negatively affected by exposure to oxygen due to oxidation, and therefore how the quality of extra virgin olive oil can be improved by limiting the exposure of extra virgin olive oil to oxygen. In C. Fadda, A. Del Caro, A. M. Sanguinetti, P. P. Urgeghe, V. Vacca, P. P. Arca, 1, A. Piga “Changes during storage of quality parameters and in vitro antioxidant activity of extravirgin monovarietal oils obtained with two extraction technologies”, Food Chemistry, vol. 134, p. 1542-1548 (2012), it is disclosed how the use of a moderate vacuum (absolute value 0.2 atm or 152 mm Hg) during storage of olive oil can improve or preserve the quality of olive oil. Olive oil producers have reported positive effects of applying vacuum during blending with the same effect (http: / / apollooliveoil.com / press.php), but the exact amount or level of vacuum is not disclosed. However, in this prior art, the vacuum level or amount of vacuum used and the purpose of the vacuum are different from the vacuum used in the present invention. All prior art has been focused on how to confine the processed oil or paste during processing to avoid exposure to oxygen (due to oxidation), and how to use a moderate / less effective vacuum to achieve this goal. However, in the present invention, a stronger or deeper vacuum is applied to extract water or steam from the pulp of the oily fruit, surprisingly resulting in a greatly increased release of oil from the pulp.

[0048] In Clodoveo, Maria Lisa, "An overview of emerging techniques in virgin olive oil extraction process"; Journal of Agricultural Engineering, vol. XLIV, p297-305 (2013)), the use of pulsed electric fields, power ultrasound or microwave radiation for enhancing oil release during olive oil production is disclosed among other emerging technologies. However, none of the new emerging technologies disclosed have the same beneficial effects of greatly increasing oil release and improving oil quality without increasing temperature.

[0049] The use of vacuum cookers with optional aroma or flavor recovery units for removing water and improving aroma recovery is also generally known within the food industry. By using vacuum cookers, the temperature during food processing can be reduced, resulting in more moderate conditions and improving the quality of the processed food. However, the use of such equipment for improving oil recovery has not been disclosed earlier.

[0050] Another oleaginous fruit used for oil production is the palm fruit. The production process of palm oil is different from that used for olive oil, using higher temperatures and more demanding methods. During the production process of palm oil, oil is extracted from the palm fruit in a so-called palm oil mill. At the front end of the process, the fruit bunches are "sterilized" under high pressure by injecting steam at about 145°C for 90-120 minutes, where the palm bunches are cooked or softened and sterilized. After the sterilization step, the palm fruit is very easy to separate from the palm bunches because it is softened. In addition, due to the increased moisture content of the palm fruit after the high temperature steam injection, crude palm oil can be more easily extracted from the palm fruit in subsequent operations. The pulp or oily flesh is then processed in a "digester" (typically a steam-jacketed stirred vessel operated at 90-95°C for 15-20 minutes), see Vugts, JA,"Palm Oil Process The Principle & Operational Techniques", https: / / vdocuments.site / palm-oil-process-the-principle-operational-techniques.html (retrieved 18Sep 2018) (Vugts, JA,"Palm Oil Process The Principle & Operational Techniques", https: / / vdocuments.site / palm-oil-process-the-principle-operational-techniques.html (retrieved 18Sep 2018)). Due to the mechanical action of sterilization and cooking as well as threshing and pounding, the palm pulp (or oily flesh) becomes soft and the cellular structure of the tissue is changed, resulting in easier extraction of oil from the pulp. Finally, the oil is separated from the pulp, usually by using a screw press, to produce crude oil and oily solid waste.

[0051] As explained above, it is known from the prior art that high temperature treatment of palm fruit will soften and destroy the pulp structure, resulting in easier release of palm oil. For more heat-sensitive and more expensive olive oils, such treatment is unthinkable. Temperature control during olive oil production is highly important because temperatures above 30°C adversely affect the quality of the oil because the natural flavor and nutrition in olive oil are very sensitive to temperature. However, in principle, there may be considerable possibilities in extracting crude palm oil under moderate conditions for maximizing the preservation of nutrition and antioxidants to produce high-quality oil called "red palm oil" (https: / / www.aocs.org / stay-informed / read-inform / featuredarticles / red-palm-oil-february-2017). Red palm oil is a "virgin palm oil" in which nutrition is preserved to the maximum extent, one of which is red carotene, a precursor of vitamin A, for which it is named. Such virgin oils will only require moderate post-processing to adjust its sensory properties about oil to be acceptable to most consumers.

[0052] A similar industry to the one described is the Avocado Oil Production industry. Briefly, it consists of three stages: - Washing and crushing / pitting: After harvesting, the avocados are washed. The avocado pulp is then crushed with or without the pit to obtain a paste.

[0053] - Blending: During blending, the paste is gently mixed and heated at 45-55°C for a period of 45 to 120 minutes, and the oil is then released from the capsules that encapsulate the oil. This stage is therefore crucial for the yield and quality of avocado oil.

[0054] - Separation: After agitation, the paste is pumped to a decanter (2-phase or 3-phase) for subsequent separation. As a result, the paste is separated into oil, water (vegetable water plus added water) and solids (three phases). Furthermore, dilution water is added to fluidize it. On the other hand, in the two-phase process, the paste is separated into a light phase (oil) and a solid phase (pomace). Depending on the water content of the raw materials, the two-stage process requires little or no addition of dilution water.

[0055] So far, no method has been developed that allows obtaining high yields of high-quality olive oil at low temperatures in a short time. To obtain high yields of olive oil using current methods, the mixing step must be significantly extended to more than 1 hour if the temperature is kept low. Other solutions to increase oil yields are to increase the temperature to more than 30°C. And in order to significantly increase the yield, both the mixing time and the temperature must be changed. Those factors significantly deteriorate the quality of the oil.

[0056] Additionally, to obtain good oil yields, current methods need to start with olives that have sufficient maturity to soften the tissue and preferably also have low moisture.

[0057] The present invention discloses the use of vacuum at low temperatures to soften and damage the oily pulp, thereby enhancing the release of oil. It was surprisingly found that the use of vacuum at low temperatures will not only inhibit the adverse effects of oxygen on oil quality, but will also significantly increase the yield of oil compared to conventional methods without negatively affecting the quality of the oil. Moreover, the method disclosed in the present invention not only significantly increases the yield of oil, it also improves the quality of the oil obtained.

[0058] The method disclosed in the present invention also allows the processing of olives or other oleaginous fruits with different degrees of maturity and softness and with different moisture without affecting the oil yield obtained. In addition, the present invention also eliminates the addition of extraction aids during the extraction process and prevents the destruction of antioxidants, reducing oxidative rancidity by eliminating the presence of oxygen during most of the process.

[0059] The process disclosed in the present invention also allows the olive skins (pomace) from the first olive oil extraction to be subjected to a second extraction to obtain additional oil (re-milling). Summary of the invention SUMMARY OF THE INVENTION The invention is based on different treatments of the olive paste in the stages (2 or 3 phases) before entering the decanter. The oleaginous fruit is pretreated in a conventional manner, that is, the freshly harvested oleaginous fruit is debranched, defoliated and cleaned. The oleaginous fruit is then ground (for example using a crusher or pitting) to obtain a mixture of crushed oleaginous fruit, an oil-in-water emulsion and a large amount of air. After pretreatment, the decomposed tissue or pulp of the oleaginous fruit enters a vacuum extractor, which replaces the conventional mixing step. In the vacuum extractor, the pulp is subjected to a vacuum, which causes the release of water by evaporation or boiling of water in the pulp, while also stripping the pulp from the dissolved air (oxygen). Depending on the temperature and the intensity or amount of the vacuum used, the water is released as water vapor, with more or less water droplets entrained therein. During the vacuum treatment, the extraction of water from the oleaginous fruit tissue softens the tissue and causes changes in the cellular structure of the pulp, thereby enhancing the release of oil from the oleaginous pulp.

[0061] Detailed disclosure of the invention As explained above, freshly harvested oily fruit raw materials are prepared by methods such as debranching, defoliation and cleaning. Then, the oily fruit is ground, for example, using conventional methods, to obtain pulp or paste, which is a mixture of broken decomposed cell tissue of the oily fruit, water-in-oil emulsion and a large amount of air. In one embodiment of the olive oil production of the present invention, the obtained paste is processed with a rotating blade screen such as a cylindrical screen with perforations. The blade pushes the paste through the sieve hole mouth to separate the pulp tissue. In addition, in the screen, the broken core is separated, and due to its larger size, it is pushed by the blade through the center of the cylinder toward the end opposite to the paste input. Then, through the mixing process, they will be combined again to prevent the loss of pulp adhering to the broken core. It is also possible to use a screen with higher separation efficiency, which does not require a mixing stage, and the production capacity can be increased only by processing the paste and discarding the clean nuclear fragments. In this embodiment of the present invention, the sieved and / or unified paste then enters the vacuum extractor of the invention. In the present invention, the vacuum extractor replaces the traditional mixing step. The vacuum extractor applies a vacuum to extract water from the pulp by evaporation or boiling. The water extracted mainly from the cell tissue or intracellular juice of the oily fruit in question is extracted from the pulp because the water evaporates and carries more or less entrained water droplets, depending on both the amount or intensity of the vacuum applied in the extractor and the temperature. In addition, the air dissolved in the pulp will be stripped from the pulp. One can speculate that this type of abnormally increased oil release is due to the softening and dissolution of the oily fruit tissue when water is extracted from the cells of the oily fruit tissue. Another possible contributing factor to the surprisingly excellent oil yield may be the changed physical properties of the mixture of water vapor and paste.

[0062] Furthermore, the vacuum extractor has the advantage of working in the absence of atmosphere and dissolved oxygen, which prevents oxidation and significantly increases the shelf life of the oil. This stage ends with the release of the olive oil from the paste, which will then be separated using traditional methods at a later stage.

[0063] The solid phase is separated from the liquid phase using centrifugal force in a decanter or by any other suitable separation device. In this embodiment of the invention, a two-phase or three-phase decanter may be used. Alternatively, the phases may also be separated by using a press or any other suitable method. In this embodiment, the impure oil is subjected to vibration filtration to eliminate coarse impurities.

[0064] The invention will be further described as will be with reference to the following figures.As shown in the examples of the invention, the method described herein allows to obtain large quantities of high quality olive oil.

[0065] During the discussion and disclosure of this invention, the following definitions apply: Bud: One year old branch.

[0066] Oil mill: A facility or place where oil is obtained from olives.

[0067] Wastewater: Plant fluids and water released from olive paste.

[0068] Olive pie: The solid part of the olive, a mixture of pit, skin, pulp and pomace from which most of the oil is extracted.

[0069] Pomace: A by-product obtained through a continuous two-phase extraction system. It is a mixture of water and olive cake that can also be used as fuel or even as compost after the drying process.

[0070] Sieve: A wire mesh with multiple perforations. In this invention, it can be made of stainless steel with a cylindrical shape, with circular perforations of different diameters (1, 1.5 and 2 mm). According to this invention, its function is to produce cell disruption.

[0071] Veraison state: The degree of ripeness of the olive is consistent with the color change of the skin.

[0072] Vegetative water: A residual liquid with a brownish watery appearance. This liquid has a pleasant odor, but a bitter taste. This effluent, with a relatively high organic content, constitutes a source of pollution for the olive industry.

[0073] Pulp; paste or decomposed cellular tissue: ground or mashed oily pulp consisting of a mixture of broken oily fruits, an oil-in-water emulsion and a large amount of air.

[0074] Hold; stirring time: the time the oily fruit paste slurry is exposed to the vacuum in the vacuum extractor (the time it remains in the vacuum extractor).

[0075] Oily fruit: includes any kind of fruit from which oil can be released by processing. Examples of oily fruits are olives, palm fruit and avocado.

[0076] Vacuum: As used in this publication, a vacuum refers to an applied pressure that is less than the surrounding atmospheric pressure.

[0077] Saturated water pressure: As referred to in this publication, saturated water pressure is the vapor pressure of pure liquid water at a given temperature. When the system pressure equals the saturated water pressure at a given temperature, the boiling point is reached and the liquid water changes (boils) to steam.

[0078] Simmer: As referred to in this publication, simmering is when the system pressure is above the saturated water pressure at a given temperature, generating a significant amount of steam.

[0079] Vacuum Extractor / Oil Extractor: An airtight container or vessel suitable for applying a vacuum. BRIEF DESCRIPTION OF THE DRAWINGS

[0080] Figure 1: An image of an extractor according to an embodiment of the invention.

[0081] Figure 2 : Image of an extractor according to one embodiment of the invention, detailing the scraper blade.

[0082] Figure 3 : Diagram of the stages of an olive oil extraction process according to the prior art.

[0083] Figure 4 : Diagram of the stages of an olive oil extraction method according to one of the embodiments of the invention.

[0084] Figure 5 : A graph demonstrating the effect of the relationship between vacuum (pressure) and temperature on the boiling point of water.

[0085] Figure 6 : Schematic diagram of an embodiment of the present invention, disclosing a possible continuous setup. DETAILED DESCRIPTION

[0086] In the invention Figure 1 In the embodiment of the invention, the extractor is made of 4 mm AISI 18 / 8304 high quality stainless steel sheet. In addition, all its metal parts are made of the same quality stainless steel.

[0087] Below this follows a detailed description of each element in the figure according to one embodiment of the invention. Not only dimensions but also values ​​or materials form part of this embodiment of the invention, but these are non-limiting factors and are only mentioned as possible embodiments of the invention.

[0088] Figure 1 : A schematic diagram showing a part of a batch processing plant for oil comprising a vacuum extractor (100). The vacuum extractor (100) comprises a shaft (1) which supports a scraper arm and has an auger attached thereto. The scrapers push the paste downwards due to their inclination relative to their axis and the auger pushes the paste upwards. A gear motor (2) in the oil bath controls the spindle. The gear motor (2) rotates the agitator through a transmission (variable between 20 and 60 rpm in this embodiment).

[0089] The shaft is sealed in a shaft seal (3) which prevents loss of vacuum. A vacuum pump connection (4) is located in the top section to prevent the paste from entering the vacuum system. As it was mentioned before, a large amount of air is incorporated into the freshly ground paste. When the paste comes into contact with the vacuum, the evaporation of water and the release of air will cause the paste to increase in size, forming bubbles which burst as they rise. Furthermore, as explained above, not only is air and water vapor removed by the applied vacuum, but water in the form of drops is also entrained in the vapor and air flow from the paste in the vacuum extractor. The vacuum extractor (100) also includes a cleaning or maintenance door (5) which, due to its size, allows an operator to enter and its cover has a seal for airtightness when adjusted to prevent loss of vacuum. The pre-treated (not in Figure 1 The oily pulp or paste of the present invention (shown in Figure 1) is introduced into the vacuum extractor (100) through the product inlet (6). In this embodiment, the diameter of the product inlet (6) is 76.2 mm (3 inches), with the valve and nozzle pointing to the lower part of the extractor, but this size may be different for different embodiments of extractors with different capacities. The product input is carried out by vacuum suction. The vacuum extractor (100) also includes a scraper blade (7) which has the function of scraping the annular temperature regulating bushing, preventing adhesion and pushing the paste to the bottom of the container. The bushing or temperature regulating lung or temperature regulating controller device (8) controls the temperature inside the vacuum extractor (100). As the paste is exposed to the vacuum, the temperature of the oily fruit paste will decrease, and such temperature regulation (in this case the lung (8)) is required to keep the temperature constant at a preferred level. The lung (8) can circulate hot water if the paste needs to be heated, or cold water if the paste needs to be cooled. The temperature control element (8) of this embodiment is cylindrical, double-walled, and water comes from the bottom (8a), circulates upwards, and after flowing through the inner tube, it comes out from the lower part (8b). The ideal temperature inside the vacuum extractor of the present invention varies between 0°C and 35°C, preferably between 15°C and 30°C, more preferably between 18°C ​​and 27°C, still more preferably between 20°C and 27°C, most preferably between 22°C and 26°C. The bushing (8) of the current embodiment can be replaced by other types of heat exchangers in other embodiments that can keep the paste at the preferred temperature, or can also be avoided by preheating or precooling the paste or pulp before entering the extractor.

[0090] In this embodiment, the heat exchange surface in the two bushings is about 5 m 2 .

[0091] The vacuum extractor (100) also includes an auger (9) connected to the shaft (1). The function of the auger (9) is to lift the paste deposited at the bottom of the extractor to recirculate it and keep it in continuous contact with the surface where the deepest vacuum conditions exist. A product outlet valve (10) is placed at the bottom of the vacuum extractor (100). The paste passes through the product outlet valve (10) towards a pump, which sends it to a separation device (such as a decanter) to adjust the flow rate according to its capacity. In this embodiment, its size is 127 mm (5 inches), but this size may be different for extractors with different capacities. A steam ejector (11) is placed in the vacuum extractor (100) above the surface of the oily paste. Its function is to move the paste during draining the extractor to avoid its contact with air to prevent the paste from oxidizing and adhering to the walls of the extractor. In other embodiments, an inert gas or other suitable means may be used.

[0092] The tubular condenser (12) is connected to the vacuum pump connection (4) and the vacuum extractor (100) via a vacuum connection inlet (13). The vapor mixed with the olive flavor condenses when passing through the frozen condenser. The tubular condenser (12) is used to recover the flavor escaping the paste during the exposure of the oily pulp to the vacuum. The flavor (volatile or entrained droplet portion) is condensed by cooling in the tubular condenser (12) and then collected in a sealed condensate collection container (17) together with the condensed water before returning to the oily pulp in the vacuum extractor (100). A cross section of the tubular condenser (12) is shown in (12a), indicating the cooling tubes of the tubular condenser (12). The tubular condenser (12) has a cooling liquid inlet (15) and a cooling liquid outlet (16). In this embodiment, the cooling liquid is recirculated at 4°C by passing through a refrigerator. The condensate collection container (17) collects the condensed fluid and the flavor. In addition, the condensate recovery container (17) of this embodiment has a cooling liquid circulation coil (17a) (or other exchange system) in which the cooling liquid is also circulated at 4°C to keep the condensate at a low temperature and prevent them from volatilizing due to the release of vacuum pump gases. The condensate collection container (17) also includes a condensate flavor exhaust pipe (18) which is introduced into the container (17) as a height trap due to the vacuum entering at a height greater than its exhaust. A vacuum pump is connected to the condenser (17) through a vacuum inlet (19) and has a vacuum capacity or flow rate required for the size (20) of the extractor manufactured. The vacuum extractor (100) has a paste or pulp outlet pipe (21) and its product outlet valve (10) connects the vacuum extractor (100) to a suitable separation device (such as a decanter (not shown)). Once the oil is extracted from the paste, the valve (10) opens to feed the screw pump (22) which distributes the appropriate flow rate for the type of separation (such as a decanter used).

[0093] In one embodiment of the invention, the extractor is 3300mm in height and 1100mm in diameter. The outer water jacket is 1000mm in height and 1100mm in internal height, with 100mm of the inner facing tubular cylindrical extension made of 4mm thick stainless steel.

[0094] The equipment has control and safety devices: sight glass with steam generator (for internal cleaning), thermometer, vacuum gauge and water inlet valve.

[0095] Since the principle is to bring the paste surface into contact with the vacuum, there can be extractors designed with different formats and sizes, so as long as it complies with the physical principles of the present invention, a continuous extractor can be designed, such as Figure 6 Embodiments are disclosed and described in detail below.

[0096] The following describes in detail Figure 1 The vacuum extractor functions of an embodiment of the present invention.

[0097] The oily fruit paste enters the extractor (100) through the product inlet (6) drawn by vacuum from the mixing container. The paste enters using a scraper blade (7) rotating at a suitable speed, in this embodiment, between 40 and 60 rpm, depending on the variety, maturity and humidity of the oily fruit to be treated. The movement of the scraper blade (7) is generated by a gear motor (2) and transmitted by the shaft (1). In the portion of the oily paste under vacuum at any given point, that is, in the paste at the surface or near the surface, the vacuum will cause water to evaporate from the oily paste. It is assumed that such water extraction causes intracellular destruction within the oily fruit tissue. In addition, in the case of applying vacuum by a vacuum pump (20), it is assumed that the emulsion is destroyed and the oil is extracted intracellularly from the vacuole (intracellular container surrounded by a plasma membrane containing oil in olives), water and gas. However, the very large amount of oil released by the present invention at such a low temperature is extremely surprising, and the abnormal increase in oil release based on the exact physical and chemical phenomena can only be speculated.

[0098] Due to the movement generated by the scraper blade (7) and the auger (9), the paste is recirculated and the vacuum effect can be observed as bubbles in the surface of the oily paste through the extractor display (not shown). The paste circulation is carried out with the help of the auger (9) and the scraper blade (7). The action of the scraper blade (7) causes the paste to fall to the bottom of the extractor, where the auger (9) takes it away and conveys it upward again, thus achieving a continuous cycle. The purpose of the recirculation is to move the paste to the surface so that it comes into contact with the vacuum provided for achieving water extraction. Also during said recirculation, the paste is in contact with a temperature regulating bushing or lung (8) which exchanges heat with the paste to keep it at a temperature between 0°C and 35°C, preferably between 15°C and 30°C, more preferably between 18°C ​​and 27°C, still more preferably between 20°C and 27°C, most preferably between 22°C and 26°C or any other desired temperature during extraction. The gas extracted from the paste by the vacuum is circulated through the vacuum pump connection (4) toward the tubular condenser (12), where the flavor in the condensate collection container condenses (17). The extraction is completed when the paste stops bubbling. This can be observed through a sight glass provided in the extractor (not shown). The time required to complete the process of the current embodiment is about 40 minutes. However, the time required will depend on several factors, such as the paste fluidity in the extractor, the maturity of the oily fruit, the type of oily fruit and the variety of oily fruit, the temperature applied, the surface area of ​​the paste, the amount of movement within the paste, etc., and the design of the vacuum extractor. As a larger area of ​​the paste is exposed to the vacuum, the required mixing time will be shortened accordingly. Once the process is completed, in the current embodiment, the mixing speed is reduced to 20 rpm to avoid the formation of emulsions when the vacuum is drawn. Since the current embodiment is a batch process, the next step is to turn off the vacuum pump (20) and activate the steam ejector (11) to avoid air ingress when the vacuum is broken and the extractor is emptied. The discharge of the extractor is carried out through the product outlet valve (10) and the paste outlet pipe (21). The pump (22) sends the paste towards a separation step or device, in this embodiment a decanter, and using this pump (22) the flow of the paste will be adjusted so that it is suitable for said separation device or decanter. Before this and after stopping the vacuum, the condensate from the condenser (12) is added to the paste.

[0099] The auger (9) is located within the cylinder and its height is greater than the temperature regulating liner or lung (8). This facilitates a higher fill height of the extractor.

[0100] Using the vacuum effect of the present embodiment, i.e. the vertical design of the vacuum extractor (100), different mixing speeds are possible. The preferred speed for the vertical vacuum extractor (100) is between 40 rpm and 80 rpm, such as between 50 rpm and 70 rpm, or more preferably between 55 rpm and 65 rpm, or still more preferably at about 60 rpm.

[0101] There are several well established methods for flavor recovery, and any of them may be used in this invention.

[0102] Figure 2 yes Figure 1 Close-up view of the vacuum extractor shown in Figure 2, showing details of the scraper blade (7).

[0103] Figure 3 Diagram showing the stages of an olive oil extraction method according to the prior art.

[0104] Figure 4 A diagram of the stages of an olive oil extraction method according to one of the embodiments of the invention is disclosed.

[0105] Figure 5 Show the relationship between water evaporation, temperature and pressure.

[0106] The method of the present invention uses vacuum to partially evaporate water from an oily fruit paste by reducing the system pressure on the paste surface to or close to the saturated water vapor pressure at a given temperature. The temperature range of the present invention is from 0°C (corresponding to 4.6 mmHg absolute pressure) to 50°C (corresponding to 92.5 mmHg absolute pressure). See Table 1 below.

[0107] However, since water begins to evaporate before it reaches its boiling point, the present invention will work over a wider range of vacuum and temperature. Figure 5 The solid line represents the pressure of water at boiling temperature and pressure and the dashed line represents the boiling pressure + 50 mm Hg at a given temperature (at which a large amount of evaporation will be observed). Figure 5 The entire range between the solid and dashed lines is used.

[0108] The preferred temperature interval for vacuum extraction of the present invention is from 0°C (where water will boil at 4.6 mm Hg absolute pressure and significant water evaporation starts at about 54.6 mm Hg absolute pressure) or 10°C (where water will boil at 9.2 mm Hg absolute pressure and significant water evaporation starts at a pressure of about 59.2 mm Hg absolute pressure) to 45°C (where water will boil at 71.9 mm Hg absolute pressure and significant water evaporation starts at about 121.9 mm Hg absolute pressure). Depending on the type and therefore properties of the oily fruit, there will be a more preferred temperature range. For olive oil paste, the preferred range will be between 0°C (where water boils at 4.6 mm Hg absolute pressure, and significant water evaporation will begin at about 54.6 mm Hg absolute pressure) and 35°C (where water will boil at 42.2 mm Hg absolute pressure), preferably between 15°C (where water will boil at 12.8 mm Hg absolute pressure) and 30°C (where water will boil at 31.8 mm Hg absolute pressure, and significant water evaporation will begin at about 81.8 mm Hg absolute pressure), more preferably between 18°C ​​(where water will boil at 15.5 mm Hg absolute pressure, and significant water evaporation will begin at about 65 mm Hg absolute pressure) and 27°C (where water will boil at 26.7 mm Hg absolute pressure, and significant water evaporation will begin at about 76.7 mm Hg absolute pressure), still more preferably between 20°C (where water will boil at 17 mm Hg absolute pressure, and significant water evaporation will begin at about 67.5 mm Hg absolute pressure). The preferred temperature and pressure ranges for other oily fruits will depend on the temperature to which the oily fruit and the oil will tolerate during processing. See Table 1 below which shows the relationship between water evaporation pressure and temperature.

[0109] Table 1. Relationship between water evaporation, temperature and pressure Figure 6Another embodiment of the present invention is disclosed, wherein the oily fruit is processed in a continuous manner. The oily fruit paste (A) enters the first vacuum extractor (1000a) through the product inlet (106) drawn by the vacuum generated by the vacuum pump (120). The vacuum pump (120) applies a vacuum to the surface (130a) of the oily fruit paste (A) through the vacuum pump connection (104). As explained above, the low pressure (or vacuum) is at the surface of the oily fruit paste (130), and thus the oily fruit paste is recirculated by the rotation of the rotating device (109a) to ensure that all the oily fruit paste will be subjected to the vacuum, and thus water is evaporated from the paste.

[0110] The first vacuum extractor (1100a) is fluidically connected to the second vacuum extractor (1100b) via a first extractor connection (124a). The extractor connection (124a) is located below the surface (130a) of the oily fruit paste slurry (A) of the first vacuum extractor (1100a), thereby allowing the oily fruit paste slurry (A) to flow from the first vacuum extractor (1100a) to the second vacuum extractor (1100b). The second vacuum extractor (1100b) is also fluidically connected to the third vacuum extractor (1100c) via a second extraction connector (130c). Figure 6 In the embodiment of the present invention, the system shown includes three vacuum extractors, but according to the present invention, any number of vacuum extractors, such as two vacuum extractors, three vacuum extractors, four or more vacuum extractors, can be used to perform continuous vacuum extraction. The second (1100b) and third (1100c) vacuum extractors also include rotating devices (109b and 109c) for recycling the oily fruit paste (A) to the oily fruit paste surface (130b) and (130c), respectively. All three vacuum extractors (1100a; 1100b and 1100c) are fluidly connected to the vacuum pump (120) via a vacuum pump connection (104). In addition, all three vacuum extractors of the current embodiment are fluidly connected to the product outlet (121), which, together with the product outlet pump (110), transports the vacuum-treated and extracted oily fruit product (B) of each extractor to a separation device, such as a decanter (not shown), for emptying the entire system at the end of the continuous treatment.

[0111] Another embodiment of the present invention is a continuous system with two or more vacuum extractors (1001a; 1001b; 1001c, etc.), wherein the vacuum extractors work in parallel through separate batch processes. 124a and 124b are closed, and there is no fluid connection between the vacuum extractors. Each vacuum extractor (1001a; 1001b; 1001c, etc.) processes in batches, and each vacuum extractor has a separate or at least separately controlled slurry supply system (104a; 104b; 104c (not shown)). The slurry is alternately filled into the separate vacuum extractors and discharged separately, resulting in a continuous process of separate batches in parallel, so that a continuous system can be realized without a fluid connection between the vacuum extractors.

[0112] In yet another embodiment, the continuous process uses a recirculation pump instead of the fluid connection (124) to recirculate and return the oily fruit paste slurry from one vacuum extractor (1100a) to the next vacuum extractor (1100b) in a continuous succession and continuous processing of the oily fruit paste slurry.

[0113] The vapor and gas extracted from the paste by the vacuum action are circulated through the vacuum pump connection (4) toward the tubular condenser (12), where the water vapor, flavor and other condensables are condensed and collected in the condensate collection container (17). The extraction is completed when the paste stops bubbling. This can be observed through the sight glass provided in the extractor (not shown). The time required to complete the process of the current embodiment is about 40 minutes. However, the time required will depend on several factors, such as the paste fluidity in the extractor, the maturity of the oily fruit, the type of oily fruit and the variety of oily fruit, the temperature applied, the surface area of ​​the paste, and the amount of movement within the paste.

[0114] In various embodiments of the present invention, the holding time or stirring time will be determined by the volume of the paste in each vacuum extractor and the number of industrial vacuum extractors used and the throughput (or the processing capacity of the processing line). Therefore, the possible holding time (the time span that the oily fruit paste is exposed to the vacuum in the vacuum extractor) is highly variable. In one embodiment of the present invention, the holding time is between 20-50 minutes, preferably between 30-40 minutes, and more preferably between 35-45 minutes. In another embodiment, the holding time can change anywhere between 10-190 minutes.

[0115] The flavor condenser (112) is connected to the vacuum pump connector (104). The condenser (112) is used to recover the flavor that escapes the oily fruit paste slurry with the water vapor during the exposure of the oily fruit paste slurry to the vacuum. The condenser (112) condenses the water vapor, flavor and other condensables by cooling, and the condensate is directed to a collection container (117), from which the condensate is returned to the product (B) stream in the product outlet (121) before the product (B) passes through the product outlet valve (110) and enters the separation step (not shown). In one embodiment, the condensate and flavor are directly returned to each vacuum extractor (1100a, 1100b, 1100c). In one embodiment, the return of the condensate and flavor is performed by gravity by placing a condensate collection container (117a, 117b, 117c (not shown)) above each vacuum extractor.

[0116] As indicated by dashed lines 131a and 132a, the volume of the first vacuum extractor 1100a above the surface of the oily fruit paste 130a is greater than the volume of the oily fruit paste slurry within the first vacuum extractor 1100. The same principle applies to the second (1100b) and third (1100c) vacuum extractors, but without Figure 6 Shown in.

[0117] In one embodiment of the present invention, the processing space or volume (131) above the oily fruit paste slurry surface (130) has a height between 50 cm and 150 cm, preferably between 75 cm and 125 cm, more preferably about 100 cm (for exposing a large surface 130). In another embodiment, the processing space (131) above the oily fruit paste slurry surface (130) is at least 100 cm or the largest of the diameter dimensions of the vacuum extractor (1100a; 1100b; 1100c).

[0118] In one embodiment, the vacuum extractors (1100a, 1100b and 1100c) have an elongated horizontal form, creating a larger area of ​​the oily fruit surface (130), thereby increasing the amount of the oily fruit paste (A) that is subjected to the vacuum in the vacuum extractors. Figure 6 In the embodiment of Figure 1The horizontal design results in a significantly larger surface area (130a, 130b, 130c) exposed to vacuum than in the vertical variation of the vacuum extractor 100 of the embodiment shown in FIG. Therefore, the horizontal design results in a significantly larger portion of the oily fruit paste slurry being exposed to vacuum at any given time. The larger surface area (130a, 130b, 130c) and more vacuum exposure of the horizontal design will reduce the need for vigorous mixing in the vacuum extractor (1001a, 1001b, 1001c). In one embodiment of the present invention with a horizontal design of the vacuum extractor, the preferred mixing speed will be between 5-30rpm, preferably between 10-25rpm, more preferably between 15-25rpm, such as between 20-25rpm, more preferably about 20rpm.

[0119] In different embodiments of the present invention, depending on the composition of the paste and the design of the vacuum extractor (100), such as the vertical design of the vacuum extractor (100) of this embodiment, Figure 6 In the horizontal design of the vacuum extractor (1001a, 1001b, 1001c) disclosed in the invention, the mixing speed may vary between 5-80 rpm. In a preferred embodiment using a vertical design of the vacuum extractor (100), the mixing speed is between 20-80 rpm, such as between 30-60 rpm, more preferably between 30-50 rpm, such as between 35-45 rpm, preferably about 40 rpm.

[0120] In one embodiment of the present invention, the airtight container of the vacuum extractor (100, 1100a, 1100b or 1100c) has a cylindrical shape; wherein the diameter-to-length ratio is between 1:2 and 1:5, such as preferably between 1:2 and 1:4, and more preferably a diameter-to-length ratio of about 1:3, and the container is preferably substantially horizontally elongated or horizontal.

[0121] In one embodiment, wherein the oil extraction apparatus is adapted for continuous operation mode, the average resting time of the oily fruits in the airtight container is preferably between 10 and 60 minutes, preferably between 20 and 30 minutes, such as about 25 minutes.

[0122] As demonstrated in the examples below, the oily fruit paste slurry entering the vacuum extractor of the present invention will have a high level of water content, which for olive oil is 50-65% by weight. When the product (B) leaves the vacuum extractor (100) or extractor (1100a; 1100b; 1100c) pipeline through the product outlet (21 or 121), most of the water content has evaporated during exposure to the vacuum in the vacuum extractor. In one embodiment of the present invention, the water content of the product (B) is between 10% and 40%, preferably between 20%-30%, such as about 25%.

[0123] Detailed description of embodiments In one embodiment of the invention, a high quality olive oil extraction method is developed that provides increased yields compared to currently used methods.

[0124] In the example of the invention, cleaned olives were ground using a conventional hammer crusher rotating at 2400 rpm with a screen of about 5 mm. As a result of this process, an olive paste was obtained consisting of 1.5-3.5% pericarp (skin), 70-80% mesocarp (pulp), 15-28% endocarp (stone), 2-4% seeds (nuts) and an oil-in-water emulsion.

[0125] In an additional embodiment of the invention, upon leaving the mill, the ground olives pass through a sieve. The sieve has a rotating blade operating at a speed of 800 rpm and has a sieve with a circular aperture whose diameter can vary from 1 to 4 mm. The action of the sieve causes an almost complete rupture of the tissue, exposing the cells containing the oil inside them to the subsequent processes carried out in the extractor of the invention. Through the center of the sieve, the blade pushes the woody endocarp fragments (cores) to the end opposite to the pulp input. In addition, the mesocarp (containing most of the oil) is pushed through the circular aperture of the sieve by the rotating blade, producing a mechanical rupture of the tissue.

[0126] In one embodiment of the invention, the products obtained from the sieving process are mixed in a horizontal blade container to homogenize them.

[0127] In another embodiment of the invention, the production capacity is increased by using a high-capacity sieve to avoid the mixing process of the product obtained during the sieving process. A high-capacity sieve means a sieve capable of handling the amount of paste necessary to feed a decanter or other suitable separation device and extracting all the pulp from the olives. This is done by means of several overlapping sieves, which in turn handle the endocarp.

[0128] In yet another embodiment, the cell tissue breakdown or homogenization is performed by grinding the olives into smaller parts using a grinder or by using a conventional crusher.

[0129] In a further embodiment of the invention, the olive paste obtained by any of the cell tissue decomposition methods mentioned or any other method that allows the olive tissue to be decomposed into smaller parts is transferred to the vacuum extractor of the invention. The purpose of this step is to extract oil from the paste by applying a vacuum in the extractor. To this end, all paste surfaces are exposed to the vacuum. In an embodiment of the invention, this is done by mixing and recycling the paste in the extractor. The surface to volume ratio of the oily fruit paste can also be changed by the design of the vacuum extractor (100; 1100a; 1100b and 1100c). A larger oily fruit paste surface will expose more paste to the vacuum at the surface, resulting in more efficient and faster evaporation of water from the paste and correspondingly more oil released in the paste.

[0130] In one embodiment of the present invention, the airtight container of the vacuum extractor (100, 1100a, 1100b or 1100c) has a cylindrical shape; wherein the diameter-length ratio is between 1:2 and 1:5, preferably between 1:2 and 1:4, and more preferably 1:3, and the container preferably has a vertical orientation.

[0131] One aspect of this embodiment is based on this type of hypothesis or assumption, that is, oily fruit paste is exposed to vacuum and will cause the emulsion generated in the crushing or de-stone process to break quickly, thereby producing a large amount of free oil. A kind of hypothesis is that this can reduce the effect of lipase (the hydrolysis produced by the oil-water interface decomposes triglyceride into partial glycerides and free fatty acids). Possible assumption is that this type of situation occurs when the influence of possible synergy between esterase and beta-glucosidase or possible synergy between esterase and beta-glucosidase is limited. Two enzymes are very important for converting the phenolic molecules of fruit into aglycones and the simplest phenolic compounds (which migrate to oil and therefore extend the shelf life along with the increase of antioxidants). On the contrary, by suppressing the effect of polyphenol oxidase and peroxidase (due to the absence of oxygen), it is assumed that a larger amount of antioxidants present in oil are preserved compared with traditional systems. Therefore, this invention provides the ideal conditions for obtaining high-quality olive oil.

[0132] It is postulated that the vacuum applied in the extractor of the invention has a number of beneficial effects which may explain the surprisingly high increase in the amount of oil released from the paste while producing excellent oil quality, among which: -It is assumed that it extracts the intracellular fluid consisting of oil and vegetative water by vacuole rupture. Because the tissue fragments are small, almost all the oil is released.

[0133] - It was also hypothesized that evaporation of water would occur at the intercellular level within the oily fruit tissue within the paste, resulting in softer defatted oily fruit tissue and greatly increased oil release.

[0134] - It works in the absence of oxygen, preventing oxidation, thus preserving the antioxidants present in the oil and significantly increasing its storage life and nutritional value.

[0135] - It allows the processing of olives with different hydration levels without affecting the yield.

[0136] - It allows processing olives with different degrees of ripeness, without affecting the yield, in terms of total fat in the olives.

[0137] - It does not require the use of any additives such as talc or kaolinite.

[0138] In an embodiment of the invention, a steam ejector is used during the extraction process when breaking the vacuum and evacuating the extractor to avoid replacing the paste with air, which may cause small surface oxidation therein. In addition, the steam ejector helps clean the extractor surface and prevents the paste from adhering to this surface.

[0139] In another embodiment of the invention, inert gas injection is used during the extractor when breaking the vacuum, and during evacuation, to prevent oxygen from being fixed to the paste when air enters with the vacuum break.

[0140] The total time for the paste to remain in the extractor depends on many factors, such as the capacity of the vacuum pump, the exposure of the paste surface to the vacuum action (recirculation rate, in some of the embodiments), and the mesocarp particle size (the smaller the particles, the less time they will remain in the vacuum). The particle size, in turn, depends on the consistency of the mesocarp, which is determined by the maturity of the olives and the method used to break down the cell tissue. The end of the extraction can be determined by a significant reduction or absence of foaming in the paste. In embodiments of the invention, the determination of the absence of foaming is made visually.

[0141] The cell tissue breakdown by sieving is a supplement which increases the efficiency of the extractor. Using other methods would cause the paste to remain in the extractor longer to complete the extraction.

[0142] The paste processed in the extractor of the invention presents a large amount of free oil and can be separated by a two-phase or three-phase decanter or by pressing. In a preferred embodiment of the invention, a two-phase decanter is used.

[0143] The impure olive oil is then subjected to vibration filtration to eliminate coarse impurities.

[0144] Then, the product of the previous step was separated by centrifugation to eliminate traces of water and tissue.

[0145] It is worth mentioning that even when this step is completed, there will be impurities (both solid and liquid) in the oil which will have to be eliminated by other methods such as gravity settling or filtration.

[0146] A major advantage of the inventive olive oil extraction method is a direct result of the use of vacuum and the suction induced thereby to perform intracellular oil extraction.

[0147] In a particular embodiment of the invention, an olive oil extraction device is used. It is present in a sealed container with a diameter-length ratio of about 1:2, 1:3 or higher, as long as the cost-effectiveness ratio is taken into account. The extractor has between two and three circular exchanger bushings in which water can circulate, or may have any other heat exchanger, not only in shape but also in number. In another embodiment, the extractor may be free of heat exchangers if the temperature is reached by a method before entering the extractor or by room temperature. The extractor also has a vertical stirrer, which consists of a central shaft with branches and vertical extensions, and in two first spaces between the circular bushings, the stirrer has a steel scraper blade, the end of which is made of polytetrafluoroethylene or other materials that do not contaminate the paste or wear the bushing. The scraper blade stirs the olive paste towards the bottom of the extractor. There is an auger in the middle of the central annular circle formed by the first circular bushing and attached to the central axis of the stirrer, which moves the paste upward to recirculate it. The stirrer rotates in a speed range of about 40-60rpm or higher to ensure that the vacuum is in contact with all paste surfaces. Such mixing and recirculation of the paste is continued until maximum oil can be extracted from the paste. In another embodiment of the invention, the extractor has a flavor recoverer refrigerated at a low temperature of about 4°C and condensed flavor is added to the paste before emptying the extractor.

[0148] In another embodiment, the slurry recirculation within the extractor may be performed using any mechanical method that allows the slurry to be exposed to the action of a vacuum. A non-limiting example is the use of a pump together with an auger as an alternative or supplement.

[0149] The experiments disclosed in this invention were conducted in Mendoza, which is about 600 m above sea level, where the normal air pressure can accordingly be estimated to be about 706 mm Hg.

[0150] During the preferred embodiment of the current experiment, the pressure gauge reading was negative 660-670 mm Hg. Therefore, the absolute pressure range during the experiment was 36-46 mm Hg absolute. The preferred temperature during the experiment disclosed in the invention was about 27°C. At 27°C, water boils at 26.7 mm Hg absolute pressure, and significant water evaporation will occur in the 26.7 mm Hg to 76.7 mm Hg (absolute) pressure interval.

[0151] In yet another embodiment of the invention, the vacuum applied in a 1200 kg load extractor amounts to negative 650-660 mm Hg for 25-45 minutes.

[0152] In different embodiments of the present invention, the optimal combination of oil yield and oil quality will depend on the temperature applied, the vacuum applied, and the time spent during the agitation / vacuum extraction step. Those skilled in the art will know that these variables can be modified to obtain optimal results, as disclosed in publications such as Di Giovacchino, L. "Olive Oil Extraction by Pressing, Centrifugation and Percolation: Effect of Extraction Methods on Oil Yields", Olivae, vol. 36, p 14-30 (1991).

[0153] In a preferred embodiment of the invention, the mixing time is between 10-90 minutes, preferably between 10-60 minutes, more preferably between 10-45 minutes, such as preferably between 20-40 minutes, more preferably between 25-35 minutes, and still more preferably about 30 minutes. The temperature applied in different embodiments of the invention will vary between 22-35°C, preferably between 24-27°C, more preferably between 25-26°C.

[0154] As indicated in Table 1, the above applied absolute pressure is a function of the applied temperature. The applied vacuum range is between 1 mm Hg absolute pressure and 150 mm Hg absolute pressure. In one embodiment of the present invention, at a temperature applied at 22°C, the applied pressure will be between 19.8-69.8 mm Hg absolute pressure. In another embodiment of the present invention, at a temperature applied at 24°C, the applied pressure will be between 22.4-72.4 mm Hg absolute pressure. In yet another embodiment of the present invention, at a temperature applied at 25°C, the applied pressure will be between 23.8-73.8 mm Hg absolute pressure. In another embodiment of the present invention, at a temperature applied at 26°C, the applied pressure will be between 25.2-75.2 mm Hg absolute pressure. In yet another embodiment of the present invention, at a temperature applied at 27°C, the applied pressure will be between 26.7-76.7 mm Hg absolute pressure. In another embodiment of the invention, at an applied temperature of 30°C, the applied pressure will be between 31.8-81.8 mm Hg absolute; and in yet another embodiment of the invention, at an applied temperature of 35°C, the applied pressure will be between 42.2-92.2 mm Hg absolute.

[0155] In one embodiment of the present invention, the oily fruit paste is exposed to vacuum extraction, and then the solid portion of the paste is separated from the liquid using a suitable separation method, such as centrifugation in a decanter. Subsequently, according to the present invention, the solid is exposed to vacuum again for a second milling or a second mixing, after which the solid and liquid are separated again.

[0156] Even though the experiments were performed using olives and extracting olive oil, in other embodiments of the invention the developed method and vacuum extractor are also used to extract oil from other oleaginous fruits such as avocado or palm fruit.

[0157] Example The following practical and theoretical examples are provided to illustrate embodiments or features of the invention but not to limit the scope thereof.

[0158] The experiments were carried out at a pilot plant, where an oil production plant is replicated on a smaller scale. In said experiments, the method of one of the embodiments of the invention was repeated. The results show that the yield of olive oil extraction is increased by about 30% to 40% compared to the methods used in the prior art. There is also a considerable improvement in its quality. In particular, an increase in the percentage of polyphenols, a decrease in acidity and a preservation of the percentage of antioxidants, among others, were observed. To confirm this, a series of samples obtained in said experiments, including control samples obtained by traditional methods, were analyzed by renowned laboratories in Italy and Argentina. In these tests, it was confirmed that the olive oil obtained using the method of the invention showed an increase of about 50% in the total amount of polyphenols, without deterioration of other parameters.

[0159] According to the invention, the vacuum extractor used in the experiments carried out at the pilot plant has a capacity to treat 90-100 kg of olive paste. The vacuum extractor has a quasi-spherical heat exchanger with a vertical stirrer and a tube with an auger on the central axis.

[0160] Different mixing speeds were tested by attaching a transmission and the best results were obtained at 60 rpm (results not shown, but see above for disclosure on variations in mixing speed, depending on the oily fruit and the design of the vacuum extractor). The paste was treated in the vacuum extractor of the invention at a temperature of 27° C. for 40 minutes. At this combination of time, temperature and mixing speed, the best olive oil quality-extraction yield ratio was obtained (see above for disclosure on variations in temperature and vacuum applied during the mixing step and on variations in mixing time).

[0161] Below are the detailed results of experiments conducted with the following types of olives: Changlot, Arbequina, Coratina, Arauco and Arbosana. In all experiments, the control extraction was performed using the method of the prior art ( Figure 3) (method 2, without sieve, with classical blending) and the extraction is carried out with the method according to the invention (method 1). In general, green olives are used.

[0162] In the laboratory, total fat percentage analysis was performed by the Autelec method, as well as moisture percentage analysis.

[0163] The extraction yield was calculated as the ratio between the weight of oil obtained by the extraction method and the weight of olives used, multiplied by one hundred.

[0164] The machines used to perform these examples are: - Two-phase decanter in which a hammer crusher and agitator are incorporated.

[0165] - Extractor with 90kg working capacity. Exhaust with steam ejector to move the air.

[0166] The method used to obtain the sample includes the following stages: - Crushing: Grind the whole olives using a hammer crusher until a paste forms.

[0167] - Sieving: The milled paste was sieved with a cylindrical sieve. The sieve had a screen with 1 mm openings and a rotating blade (800 rpm) that separated the paste from the kernel fragments.

[0168] - Mixing: Mix the (finely ground) paste with the kernels.

[0169] - Extraction: Introduce the mixture into the extractor by vacuum. Maintain a controlled temperature as needed for each olive test / sample. Stir the sample for 40 minutes while applying the vacuum.

[0170] - Separation: Weigh exactly the amount of paste processed by the extractor. Treat sequentially with a two-phase decanter to avoid oxidation. Weigh the oil obtained to calculate the yield.

[0171] The method used to obtain the control sample consisted of the conditions indicated by the pre-established technique, adjusting the working temperature, the processing time of the mixing and processing the same kg of paste, so that both techniques were completely similar. Regarding the raw materials, the homogenized batches were taken from the same series, the same origin and the harvest date. The harvest season in Argentina runs from March (month) to June (month).

[0172] Specific details of the experiment: Changlot: The experiment was conducted at the end of March 2017 using green olives.

[0173] Arauco: The experiment was carried out in mid-April 2017 with very green olives. It is worth mentioning that the Arauco variety shows difficulties in oil extraction and low yields. This is the variety to which the classical methods suggest adding various additives (talc, kaolin or enzymes). In this experiment, for the control extraction (method 2), 3% talc was added, and for the extraction by the method of the invention (method 1), nothing was added.

[0174] Arbequina: The experiment was carried out on the first days of May 2017 using green olives.

[0175] Coratina: The experiment was conducted during the first two weeks of May 2017 using regular olives.

[0176] Arbosana: The experiment was conducted during the first two weeks of June 2017 using high-grade horny olives.

[0177] The following results are obtained: Table 2 As is clearly shown by the results in Table 2, the method of the present invention (Method 1) significantly increases yield, with the increase in yield varying from 27-49.4%. And since olive oil as a final product is expensive, every bit of yield increase is particularly important.

[0178] Oil samples from the Coratina variety were sent to the laboratory for analysis to confirm the results obtained. The samples sent included olive oil produced using the prior art method, referred to as 1716872, and olive oil produced using the inventive method, referred to as 1716871.

[0179] The following results are obtained: Table 3 The results obtained by laboratory analysis allow to show that the vacuum applied in the method of the invention is able to extract the greatest amount of polyphenols (33% in the test), therefore obtaining an oil with the highest antioxidant properties. In Table 3, we also recognize the increase of aglycones in the oil obtained by vacuum, indicating that the activity of glycosidases may be enhanced or not inhibited. At the same time, we can speculate the inhibition of the oxidative enzymes polyphenol oxidase and peroxidase, due to the reduction of oxygen from the olive paste.

[0180] The invention is not limited to the embodiments described above and shown in the drawings, but may be supplemented and modified in any way within the scope of the invention as defined by the appended claims.

Claims

1. A method for extracting oil from oleaginous fruits such as olives, avocados or palm fruits, the method comprising the following steps: providing the oily fruit in the form of a paste, and The slurry is exposed to a vacuum for causing the slurry to release oil, water vapor and flavor, wherein the vacuum defines an absolute pressure between 1 mm Hg and 150 mm Hg, and wherein the temperature of the slurry is maintained between 0°C and 45°C.

2. A method for extracting oil from oily fruits according to any one of the preceding claims, characterized in that The vacuum defines an absolute pressure between 4 mm Hg and 95 mm Hg, preferably between 36 mm Hg and 46 mm Hg.

3. A method for extracting oil from oily fruits according to any one of the preceding claims, characterized in that The temperature of the paste is maintained between 10°C and 35°C, preferably between 20°C and 27°C, more preferably between 22°C and 26°C.

4. A method for extracting oil from oily fruits according to any one of the preceding claims, characterized in that The pressure and the temperature are selected so that the slurry boils, simmers, or is maintained within the saturated vapor pressure of water in the slurry of 50 mm Hg.

5. A method for extracting oil from oily fruits according to any one of the preceding claims, characterized in that During extraction and after extraction of the oil, contact with air is avoided.

6. A method for extracting oil from oily fruits according to any one of the preceding claims, characterized in that After the oil is extracted, a gas such as steam or an inert gas is injected with the paste.

7. A method for extracting oil from oily fruits according to any one of the preceding claims, characterized in that The method further comprises the step of separating the oil from the slurry.

8. The method for extracting oil from oily fruits according to claim 7, characterized in that: The step of separating the oil from the slurry comprises using a centrifugal decanter, such as a two-phase or three-phase decanter.

9. The method for extracting oil from oily fruits according to claim 7, characterized in that: The step of separating the oil therefrom includes using a hydraulic press or using the sinolea method.

10. The method for extracting oil from oily fruits according to any one of claims 7 to 9, characterized in that: The oil was subjected to vibration filtration.

11. The method for extracting oil from oily fruit according to any one of claims 7 to 10, characterized in that: The method further comprises the step of re-milling the paste to separate the remaining phase, the process of separating the remaining phase preferably comprising a centrifugation stage or a gravity separation step.

12. A method for extracting oil from oily fruits according to any one of the preceding claims, characterized in that The average retention time of the slurry in the vacuum is between 10 and 60 minutes, preferably between 20 and 30 minutes, such as about 25 minutes.

13. A method for extracting oil from oily fruits according to any one of the preceding claims, characterized in that The method further comprises performing one or more initial steps selected from the group consisting of: a) harvesting the oily fruit; b) removing branches from the oily fruits; c) removing leaves from the oily fruit; or d) washing the oily fruit; e) crushing and / or removing the core of the oily fruit; f) processing the ground oleaginous fruit to obtain a small portion of cellular tissue; g) screening the ground oily fruit; h) mixing the products obtained by sieving.

14. The method for extracting oil from oily fruits according to claim 13, characterized in that: The step of crushing the oily fruit includes using a conical stone mill, a cylindrical stone mill, a metal crusher or removing the core.

15. The method for extracting oil from oily fruits according to claim 13, characterized in that: Screening the milled oleaginous fruit comprises separating the milled oleaginous fruit tissue and separating the milled kernels from the decomposed oleaginous fruit tissue constituting the paste, preferably using a high throughput screen.

16. A method for extracting oil from oily fruits according to any one of the preceding claims, characterized in that The method includes providing an oil extractor, the oil extractor comprising: a) one or more airtight containers; b) a pressure regulating device in communication with each of the airtight containers; as well as c) A temperature regulating device in communication with each of the airtight containers.

17. The method for extracting oil from oily fruits according to claim 16, characterized in that: The airtight container defines a breakaway height at least equal to the diameter of the airtight container or 1 m, whichever is greater.

18. The method for extracting oil from oily fruit according to claim 16 or 17, characterized in that: The introduction of the paste into the airtight container is performed by sucking or pumping the paste into the airtight container.

19. The method for extracting oil from oily fruits according to any one of claims 16 to 18, characterized in that: The oil is continuously extracted from the slurry in the oil extractor in a continuous or batch process.

20. The method for extracting oil from oily fruits according to any one of claims 16 to 19, characterized in that: The paste is recirculated, preferably using an auger operating between 8-60 rpm, more preferably between 18-35 rpm.

21. A method for extracting oil from oily fruits according to any one of the preceding claims, characterized in that After extraction of the oil, the remaining water in the paste is between 10% and 65%, preferably between 10% and 40%, more preferably between 20% and 30%, such as about 25%.

22. A method for extracting oil from oily fruits according to any one of the preceding claims, characterized in that The water vapor, flavors and / or other condensables escaping from the slurry are condensed, wherein the condensed water vapor, flavors and / or other condensables are preferably mixed with the oil.

23. An oil extractor for extracting oil from oily fruits by causing the oily fruits to release oil, water vapor and flavor, the oil extractor comprising: an airtight container for receiving the oily fruit in the form of a paste, a pressure regulating device in communication with the airtight container for exposing the paste in the airtight container to an absolute pressure between 1 mm Hg and 150 mm Hg, and A temperature regulating device is communicated with the airtight container to maintain the slurry in the airtight container at a temperature between 0°C and 45°C.

24. The oil extractor according to claim 23, characterized in that The absolute pressure is between 4 mm Hg and 95 mm Hg, preferably between 36 mm Hg and 46 mm Hg.

25. The oil extractor according to any one of claims 23-24, characterized in that The temperature is between 10°C and 35°C, preferably between 20°C and 27°C, more preferably between 22°C and 26°C.

26. The oil extractor according to any one of claims 23 to 25, characterized in that The pressure regulating device and the temperature regulating device are suitable for subjecting the paste in the airtight container to boiling or simmering, or for maintaining the paste in the airtight container within a saturated vapor pressure of the paste of 50 mm Hg.

27. The oil extractor according to any one of claims 23 to 26, characterized in that The airtight container defines a breakaway height at least equal to the diameter of the airtight container or 1 m, whichever is greater.

28. The oil extractor according to claim 27, characterized in that The device has at least one orifice above the fill level of the airtight container for communication with the pressure regulating device.

29. The oil extractor according to any one of claims 23 to 28, characterized in that The airtight container comprises recirculation means for recirculating the paste within the airtight container, the recirculation means preferably comprising an auger operating between 8-60 rpm, more preferably between 18-35 rpm.

30. The oil extractor according to claim 29, characterized in that The recirculation device comprises a horizontal or vertical agitator comprising a blade and an auger, preferably the auger and the blade are attached to a shaft that can rotate at different speeds.

31. An oil extractor according to any one of claims 23 to 30, characterized in that The introduction of the paste into the airtight container is performed by pumping the paste into the airtight container.

32. An oil extractor according to any one of claims 23 to 31, characterized in that The oil extractor further comprises a condenser intermediate the airtight container and the pressure regulating device, the condenser preferably being adapted to provide condensate to be mixed with the oily fruit paste slurry.

33. An oil extractor according to any one of claims 23 to 32, characterized in that The airtight container has a cylindrical shape; with a diameter-to-height ratio of between 1:2 and 1:5, preferably 1:3, the airtight container preferably having a vertical orientation.

34. An oil extractor according to any one of claims 23 to 32, characterized in that The airtight container has a cylindrical shape; wherein the diameter-length ratio is between 1:2 and 1:5, such as preferably between 1:2 and 1:4, still more preferably the diameter-length ratio is about 1:3, the container preferably having a horizontal orientation.

35. The oil extractor according to any one of claims 23 to 34, characterized in that The airtight container comprises an injector of a fluid, the fluid preferably consisting of steam or an inert gas.

36. An oil extractor according to any one of claims 23 to 35, characterized in that The oil extractor is adapted for a continuous operation mode, the average retention time of the slurry in the airtight container being between 10 and 60 minutes, preferably between 20 and 30 minutes, such as about 25 minutes.

37. An oil extractor according to any one of claims 23 to 36, characterized in that The oily fruit is an olive, an avocado or a palm fruit.

38. An oil extractor according to any one of claims 23 to 37, characterized in that The oil extractor is adapted to produce a paste having a residual water content of between 10% and 40%, preferably between 20% and 30%, such as about 25%.

39. A system for extracting and separating oil from oily fruits, the system comprising an oil extractor according to any one of claims 23 to 38, and a separator adapted to receive slurry from the oil extractor and separate the oil from the slurry.

40. The system according to claim 39, characterized in that The separator is a decanter centrifuge, such as a two-phase decanter centrifuge or a three-phase decanter centrifuge, or alternatively a hydraulic press system.

41. An oil obtained from the system according to any one of claims 39-40.

Images