ENZYMATIC PROCESSING OF COCONUT MEAT TO PRODUCE EDIBLE PRODUCTS
TECHNICAL FIELD OF THE INVENTION This invention relates to novel processes for treating coconut. The processes of this invention utilize aqueous enzymatic digestion to separate the constituents of coconut meat.
RELATED APPLICATIONS This application is related to and claims priority from provisional patnet application serial no. 60/182,453, filed February 15, 2000. BACKGROUND OF THE INVENTION
The constituent components of coconuts have a variety of important uses, including incorporation in both edible and non-edible products. For example, coconut oil is a major commodity product, with worldwide consumption in the range of 8 to 10 billion pounds annually. One billion pounds of coconut oil are consumed annually in the United States alone, approximately half of which is used for industrial purposes (soaps, topical creams, shampoos and the like) with the other half provided for edible use. As an edible ingredient, coconut oil is often preferred over other oils in part because it is free from phosphatides and gums that are commonly present in some other types of oil.
Conventional processing of coconut typically follows a multi-step procedure that generates undesirable waste products and tends to degrade certain constituents of the coconut. These conventional processes rely on an expeller press to remove the valuable crude coconut oil from coconut meat. The pressing operation is inherently abusive to the protein fraction of the coconut meat because it requires high pressure. The degraded proteinaceous byproduct of the pressing operation has limited utility and without further processing can only be used as an animal feed ingredient. Similarly, to become food grade, the crude oil must undergo further physical and/or chemical refinement such as clay treatment, bleaching, caustic neutralization of fatty acids (saponification), washing of soaps and deodorization. Specialized equipment is required for these processing steps, often making the overall process quite expensive. In addition, many of these conventional processing steps are arduous and time- consuming and also produce large volumes of waste effluent.
Accordingly, there remains a need for new processes for treating coconut that can generate multiple food grade and value-added ingredients, including protein, soluble fiber, aqueous-soluble micronutrients and high grade edible oil, without the disadvantages of conventional coconut processing.
SUMMARY OF THE INVENTION The novel processes of this invention meet the unmet need for improved coconut processing technology. By utilizing aqueous enzymatic digestion to separate the constituents of coconut meat, the novel processes of this invention bypass several expensive, time- consuming and potentially environmentally damaging conventional coconut processing steps. The processes of this invention may be used to produce a variety of useful and valuable coconut-derived products, including coconut oil, coconut grate, coconut protein and coconut juice.
The processes of this invention include treating a coconut slurry with an enzyme(s) and then separating the enzymatic products into at least an oil phase, an aqueous phase and a solid phase. It is an objective of this invention that the products of these three phases are edible without further treatment. The processes of this invention also include purifying the oil phase. Furthermore, the processes of this invention include separating the aqueous phase into a recyclable water product and a coconut juice concentrate, and separating the solid phase into a coconut grate product and a coconut protein product. It is also a further objective that the recyclable water product, the coconut juice concentrate, the coconut grate product and the coconut protein product are edible without further treatment. Other objectives of this invention will be apparent from the detailed description of the invention that follows.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flowchart depicting the processes of this invention.
DETAILED DESCRIPTION OF THE INVENTION
As used herein, the following definitions apply (unless expressly noted to the contrary):
"Edible" refers to matter that may be consumed by humans without significant deleterious health consequences.
"Coconut meat" refers to the white meat portion of a coconut that has been removed from the coconut's husk and shell. The processes of this invention preferably use fresh, raw coconut meat. However, dried coconut meat, or defatted coconut meat may also be used.
"Defatted coconut meat" refers to coconut meat that has undergone a process such as pressing (e.g., by an expeller press) to remove a significant portion of the oil from the coconut meat.
"Effective particle size" refers to coconut meat having an average particle size that enables the enzyme(s) to catalyze the necessary chemical reactions of the invention. "Effective quantity of water, duration, pH and temperature" refer to the values of these substances or conditions where the enzyme(s) is able to perform the necessary chemical reactions of the invention. Furthermore, in the processes of this invention, individual values of particle size, amount of water, duration, pH and temperature should be considered in relation to the values of the other treatment parameters, including the amount and nature of enzyme being used. Although this application provides guidance as to how such values should be evaluated, and sets forth particular values for certain preferred processes of this invention, it is well within the skill of the art to alter the conditions and select other appropriate parameters without undue experimentation. When no specific values are indicated, a value representing an effective parameter is to be presumed.
"Coconut slurry" refers to a mixture of coconut meat and water.
"Enzyme" refers to a type of protein molecule that acts as a biochemical catalyst.
"Enzymatic product slurry" refers to a mixture of coconut-derived products obtained as a result of the enzymatic treatment of coconut meat.
"Oil phase" refers to a product obtained by separating the enzymatic product slurry. Although this phase may contain solutes, particulate matter and water, it contains less of these substances than the solid phase and the aqueous phase. The "oil phase" primarily contains edible oil.
"Aqueous phase" refers to a product obtained by separating the enzymatic product slurry. Although this phase may contain solutes (e.g., protein molecules), particulate matter and oil, it contains less of these substances than the solid phase and the oil phase. The "aqueous phase" contains at least edible coconut juice and recyclable water.
"Solid phase" refers to a product obtained by separating the enzymatic product slurry. Although this phase may contain some liquid when isolated, it contains less liquid (i.e., water or oil) than the aqueous phase and the oil phase. The "solid phase" contains at least edible coconut grate and coconut protein.
"Purifying" refers to the process of removing some, if not all, impurities from a substance. After the purification, some impurities may remain.
"Recyclable water product" refers to a product obtained by separating the aqueous phase. Although this product may contain some solutes, particulate matter, or oil, it contains less of these substances than the coconut juice concentrate. The "recyclable water product" is primarily water of a quality (dictated by industrial efficiency and environmental regulatory standards) that may be combined with coconut meat in order to form the coconut slurry. Used in this way, it results in pollution abatement by reducing or eliminating an effluent (waste) stream.
"Coconut juice concentrate" refers to a product obtained by separating the aqueous phase. This product is a combination of at least water, and coconut protein. Depending on which process is used to separate the aqueous phase, the "coconut juice concentrate" may also
contain constituents that produce a sweet and/or fragrant quality. When the coconut juice is used as a ready-made beverage, these later qualities are especially desirable.
"Coconut grate product" refers to a product obtained by separating the solid phase. Although this product may contain oil, water, and coconut protein product, it primarily contains coconut fiber (e.g., cellulose) which remains undissolved during an alkaki extraction procedure.
"Coconut protein product" refers to a product obtained by separating the solid phase. Although this product may contain oil, water, and coconut grate product, it primarily contains protein molecules.
"Vacuum drying" refers to a procedure that removes moisture from a coconut product by heating the coconut product at a temperature greater than ambient temperature, and at a pressure less than normal atmospheric pressure (101.3 KPa absolute).
"Short path distillation" refers to the procedure of using a short path distillation apparatus that vaporizes a liquid mixture with the subsequent collection of components by differential cooling to condensation.
"About" refers to a range of +/- 5%, with the exception of pH. For example, "about 10 microns" is equivalent to "9.5 microns to 10.5 microns." When used in relation to pH, "about" refers to a range of +/- 0.2. For example, "a pH of about 10" is equivalent to "a pH of 9.8 to 10.2."
"Free fatty acids" refers to fatty acid molecules that have a free carboxyl group, that is they are not glycerol esters.
"Membrane separation procedure" refers to any procedure that in part uses a membrane that is at least permeable for water, but may be impermeable for molecules larger than water such as protein, or carbohydrate molecules.
"Ultrafiltration" refers to a membrane separation procedure that is pressure driven and whose membrane is permeable to water, inorganic salts, and small organic molecules (e.g., glucose), but impermeable to macromolecules (e.g., albumin protein).
"Reverse osmosis" refers to a membrane separation procedure that is pressure driven such that flow takes place from the higher concentration side of the membrane to the lower concentration side, and whose membrane is permeable to water and micro-organic molecules (e.g., ethyl alcohol), but impermeable to macromolecules (e.g. albumin protein), inorganic salts, and some forms of non-ionic organic compounds (e.g., fructose).
"Raw coconut" refers to coconut where only the husk and shell have been removed
(e.g., has not been dried or defatted).
"Average particle size" refers to the arithmetic mean diameter of a sample of particles.
"Pectinases" refer to enzymes that catalyze the hydrolysis of pectin.
"Cellulases" refer to enzymes that catalyze the hydrolysis of cellulose.
"Hemicellulases" refer to enzymes that catalyze the hydrolysis of hemicellulose.
"Carbohydrases" refer to enzymes that catalyze the hydrolysis of carbohydrates.
"Gravity phase separation" refers to a procedure for separating phases of a product based upon the specific gravity of each phase.
"Centrifugation" refers to a procedure using centrifuge force to separate phases based upon the specific gravity of each phase.
"Protein separation procedure" refers to any process that separates protein molecules from water, other biomolecules such as lipids, or other protein molecules. For example, the process of this invention may separate protein molecules according to their size, binding specificity, charge, or solubility.
"Protein solubilization procedure" refers to a procedure whereby a liquid containing undissolved protein molecules is treated until the protein molecules are substantially soluble in the liquid.
"Alkali extraction" refers to a procedure using a solution with a basic pH to extract protein molecules from a solid.
"Dilute" refers to a solution concentration of less than five molar.
"Isoelectric precipitation procedure" refers to a procedure whereby the pH of a solution containing dissolved protein molecules is decreased in order to precipitate the protein molecules.
Individual preferred values of various process parameters (including, but not limited to, average coconut meat particle size, temperature, pH, type of enzyme and enzyme treatment duration) apply individually to particular process steps, but can also be applied in combination with other process steps.
The processes of this invention use coconut meat having an effective particle size as the starting material. This starting material can be obtained from raw, dry or defatted coconut meat. If defatted coconut meat is used, the processes of this invention will yield little coconut oil.
To obtain fresh, raw coconut meat, the coconut husks, shells and pairings are removed using conventional methods. During this early processing stage, the coconut water (the liquid contained in the center of the coconut), which may have a high market value, can be harvested separately from the rest of the coconut. As an alternative to fresh, raw coconut meat, it is also possible to start with desiccated coconut meat. Both fresh and desiccated coconut meat
(whole, ground, shredded) may be readily purchased from retail stores, as well as a variety of commercial vendors. Coconut meat typically contains between about 50% to about 75% oil and between about 5% and about 15% protein.
To promote effective enzymatic digestion, the average coconut meat particle size may be reduced by grinding or shredding. Reducing the particle size in this manner may facilitate the enzymatic treatment. Typically, the reduction process is performed by using a food grade mill (e.g., a Szego mill). The average particle size for the processes of this invention is preferably between about 0.1 and about 50 microns; more preferably, between about 1 and about 15 microns; and most preferably, between about 5 and about 10 microns. The most favorable average particle size may depend on the particular process conditions, and can readily be determined by those of ordinary skill in the art without undue experimentation.
The enzymatic treatment is more productive with the addition of water to the coconut meat. Water may be combined with the coconut meat before, during or after the reduction process. Since heat may be produced during the reduction process, the most preferred embodiment of this invention includes introducing the water prior to the reduction process in order to minimize thermal damage to the heat sensitive constituents of the coconut meat (e.g., coconut proteins). The addition of water to coconut meat with an effective particle size results in a coconut slurry. Preferably, the coconut slurry comprises about 1 part coconut meat to between about 1 and about 20 parts water (w/v); more preferably, about 1 part coconut meat to between about 5 and about 10 parts water; and, most preferably, about 1 part coconut meat to about 10 parts water. If desired, the water temperature can be adjusted prior to its addition. In a preferred embodiment, the water is used at room temperature or heated prior its addition. Preferably, the water is between about 23°C and about 60°C; more preferably, between about 23°C and 40°C; and, most preferably, at about 35°C.
The temperature and pH of the coconut slurry may be adjusted to provide effective conditions for enzymatic treatment. Depending on the type of enzyme being used, and other treatment parameters, the pH and temperature may be adjusted before or after addition of the enzyme in order to meet the enzyme supplier's recommendation. In a preferred embodiment the coconut slurry is heated prior to addition of the enzyme. The temperature of the coconut slurry is preferably between about 23°C and about 75°C; more preferably, between about 40°C and about 65°C; and, most preferably, at a temperature of about 50°C. In another preferred embodiment, the pH of the coconut slurry is adjusted prior to addition of the enzyme to between about 3 and about 6.5; more preferably, between about 4 and about 5.5; and, most preferably, to about 4.5. To achieve these reduced preferred pH values, any suitable acid may be used. • The preferred acids for this purpose are food grade acids, such as food grade phosphoric acid.
Once the coconut slurry has been prepared, it is subjected to enzyme treatment. There are several types of commercially available enzymes that can be used effectively in the processes of this invention. Typically, these enzymes are those recommended by their manufacturers to degrade cellular structures of plant materials, such as the cell wall tissues that contain the coconut oil (e.g., cellulose and hemicellulose.) Individual enzymes may be used alone or combined with other effective enzymes to produce a particular desired result. Preferred types of enzymes for use in the processes of this invention include, pectinases, carbohydrases, cellulases, hemicellulases and combinations thereof. A combination of pectinases, carbohydrases, cellulases, and hemicellulases is particularly preferred. Specific enzymes for use in the processes of this invention include Pectinex 3xL (a pectinase), SP-249 (a carbohydrase), Celluclast 1.5L (a cellulase) and Gamanase (a hemicellulase). These four particular enzymes are available commercially from Novo Nordisk (Denmark). Gamanase is a most preferred enzyme for the processes of this invention.
The effective enzyme amount and effective temperature, pH and enzyme treatment time should be selected so as to facilitate enzymatic digestion. Individual values will largely depend on the type of enzyme being used and the values set for other enzyme treatment parameters. The enzyme manufacturers typically provide considerable guidance in this regard. In a preferred embodiment, the amount of enzyme is about 0.1% to about 5% of the
coconut meat by weight; more preferably, about 1% to about 3%, and most preferably, about 2%. The enzymatic treatment can be carried out in any suitable vessel (e.g., an agitation tank). The preferred enzymatic treatment duration is equivalent to the time when the oil yield of the process is equivalent, or almost equivalent, to the oil content of the coconut meat. Depending on the treatment parameters and the type of enzyme(s), typically the enzyme treatment duration will be between about 3 and about 36 hours. Preferably the treatment duration will be between about 5 and about 30 hours; more preferably, between about 7 and about 24 hours; and, most preferably, about 20 hours. During the treatment time, there may be a period of agitation followed by a period of non-agitation (which can take place in the same or a different vessel, such as a settling tank). For example, once the enzyme is added, the enzymatic slurry may be maintained at an elevated temperature (e.g., about 50°C) for about 5 hours with agitation, followed by about 15 hours of non-agitation at the same temperature. During the enzymatic treatment, the coconut meat of the coconut slurry is degraded into its constituent parts, resulting in the enzymatic product slurry. At this time, the oil yield of the enzymatic product slurry is monitored in order to assess the progress of the treatment. Once the oil yield of the enzymatic product slurry is close to the oil content of the coconut meat starting material, the treatment is discontinued.
Following enzyme treatment, the components of the enzymatic product slurry can be separated. Although many separation techniques can be used for this portion of the process, gravity phase separation is preferred (e.g., gravity settling or centrifugation). Most preferably, separation is performed by centrifugation. The centrifuge parameters may be readily determined by those of ordinary skill in the art. An industrial centrifuge will likely be effective with a setting of 3000-6000 X g. Using a laboratory centrifuge, on the other hand, it has been found that using an IEC fixed head rotor at about 9000 X g is effective. At least three phases should result from the separation procedure: (1) a solid phase, (2) an aqueous phase, and (3) an oil phase. The efficiency of the separation procedure is analytically determined by the cross-contamination of the phases. The separation procedure may also produce an emulsion phase. It is an object of this invention to reduce or eliminate the existence of this phase. Typically, the emulsion phase contains a mixture of oil and water that is stabilized by soluble surfactive proteins. By heating or adding an acidic solution to the
emulsion layer the layer is separated into oil and water. The resultant aqueous and oil layers can then be added to the previously obtained aqueous and oil phases, respectively. The following sections detail further characterization and treatment options for each of the three primary phases that are separated from the enzymatic product slurry.
Oil Phase
The coconut oil in the oil phase is of considerable quality. Since the enzyme treatment is relatively gentle to the coconut constituents, including the oil, the oil can be consumed without further treatment. For this reason, the coconut oil obtained is superior to conventional industry produced RBD (refined, bleached and deodorized) coconut oil as it retains its natural flavor and fragrance. Furthermore, the enzymatic treatment results in a recovery percentage that is comparable to conventional industry procedures. Typically, the coconut oil obtained using the processes of this invention represents at least about 70% of the total oil content of the coconut meat and may be as high as over 80%. Although the enzymatic treatment produces high quality coconut oil, the oil phase may be purified to yield a better product. After the separation of the enzymatic product slurry, the oil phase may have about 2% moisture content. This residual moisture can be reduced through vacuum drying to preferably less than about 1.0 %, and most preferably about 0.1 %> water by weight. This additional step helps to reduce hydrolysis of neutral triglycerides. Also, the oil phase may be subjected to short path distillation which removes free fatty acids to preferably less than about 2 %, and most preferably about 0.5% of the oil phase by weight.
Aqueous Phase
The aqueous phase obtained from the separation of the enzymatic product slurry retains a pronounced, pleasant coconut aroma, a somewhat sweet flavor and low viscosity, and may be consumed directly without further treatment. This phase typically contains about 40%) to about 55%o of the protein from the coconut meat if the pH of the coconut slurry was below about 5. The protein is solubilized in the aqueous phase under such conditions, and is typically present at a concentration of about 0.1% to about 0.5%.
Although the aqueous phase may be consumed without further treatment, this phase may be separated into at least a recyclable water product and a coconut juice concentrate. By performing this further treatment of the aqueous phase, the concentration of the protein, as well as other desirable constituents of the aqueous phase, can be increased and retained in the coconut juice concentrate. Conventional concentration techniques known to those of skill in the art, such as freeze-drying, can be used. Preferably a membrane separation procedure is used, such as ultrafiltration or reverse osmosis, although ultrafiltration may result in a loss of aroma. Reverse osmosis is preferred for industrial-scale processing. After treatment, the - coconut juice concentrate will have a final protein concentration of about 0.5% to about 1.5%. It may be desirable to pasteurize the aqueous phase before it is separated, or the coconut juice concentrate after separation.
It is a further objective of this invention to produce a recyclable water product from the aqueous phase. Typically, the recyclable water product will retain some impurities, such as residual carbohydrate and protein molecules. However, by using the processes of the present invention, the amount of impurities will be reduced and the quality of the recyclable water product will be high enough so that it may be reused. In other words, the recyclable water product may be used as the input water at the beginning of the process (see Fig. 1). As a result of the in-process recycling of the water used, this invention prevents or reduces the effluent water produced by the enzymatic treatment of coconut meat. The potential benefits from this segment of the process include cost savings, reduced legal liability, and improved corporate image.
Solid Phase
The solid phase obtained from separation of the enzymatic product slurry typically represents approximately 10-20% of the weight of the coconut meat starting material and approximately 10-20% of its total protein content. The solid phase is edible. If desired, however, the solid phase can be further processed to obtain coconut grate product and coconut protein product. To separate these components, any conventional protein separation technology can be used. Preferably, alkali extraction is first used to solubilize the proteins. In this preferred embodiment, the protein molecules of the solid phase are extracted into an
aqueous alkali solution at an effective pH, typically between about 9 and about 12.5; more preferably, between about 10 and about 12; and most preferably, between about 11 and about 12. Any effective alkali solution may be used, including sodium hydroxide, and potassium hydroxide. Dilute sodium hydroxide is preferred. Typically, water is first added to the solid phase at a ratio of about 1 part solid phase to about 10 to about 20 parts water (w/v); and preferably at a ratio of about 1 part solid phase to about 15 parts water. Then, the alkali solution is added to raise the pH of the solid phase/water combination to the effective pH. Additional volumes of the alkali solution may be added during the alkali extraction to maintain the pH of the solid phase/water combination at the effective pH. This alkali extraction solubilizes a substantial percentage of the protein in the solid layer (at least about 10% to about 85%>). Once the protein has been solubilized, the filtrate (containing the solubilized protein) can then be acidified to precipitate the protein. This isoelectric precipitation procedure is typically carried out using an aqueous acid solution at a pH of between about 4 and about 6; preferably, between about 4 and about 5; and, most preferably, at apH of about 4.5. Using this process, at least about 80% to about 90% of the dissolved protein is precipitated. The precipitated protein tends to be off-white in color and substantially free from any coconut aroma. This protein precipitate can be isolated by any conventional method. Centrifugation is preferred.
The separation of the solid phase also results in a coconut grate product which has a high plant fiber content. The coconut grate product is edible without further treatment, but may be dried using any suitable methods in order to produce a more commercially viable product. For example, a spray drying method may be used.
Without wishing to be bound by theory, the enzyme or enzymes used in the processes of this invention break down the tissue structure of coconut meat such that the oil stored in these structures is released. As a result, the coconut oil can be effectively separated from the remaining coconut constituents without harsh, conventional processing steps, such as pressing or volatile solvent extraction. Furthermore, the enzymatic treatment described herein is sufficiently mild to allow for the effective recovery of other coconut constituents, such as coconut protein, coconut grate and coconut juice concentrate. As a result, the processes of
this invention provide an economical and potentially integrated method for the complete utilization of coconut meat.
Although it is an object of this invention that the coconut-derived products obtained using the processes of this invention can be used as food grade ingredients without further processing, they may also be used in animal feed, or industrial applications. For example, the coconut oil obtained using the processes of this invention is food grade, and may be incorporated into edible products (such as cooking oil, baking ingredients or flavorizers). Alternatively, the coconut oil can also be used for industrial applications, such as detergents, soaps, creams and shampoos. Furthermore, the other coconut derived products (including coconut grate product, coconut protein product, coconut juice concentrate and recyclable water product) recoverable using the processes of this invention can also be used directly as food grade material and incorporated into edible products. For example, these coconut-derived products can be used in a host of nutritious foodstuffs (such as nature bars, drinks and drink mixes). Although many other uses of these products will be evident to those of ordinary skill in the art, the following applications are of specific interest: (1) the coconut juice product can be used as an ingredient in tropical drinks; and (2) the coconut grate product can be used as a high fiber alternative to bran and other fiber-rich material. Also, since the coconut protein product recoverable using the processes of this invention tends to have a higher protein content than soy protein, the coconut protein product can be used as an alternative to soy protein. Such applications include without limitation meat extenders, processed foods, health foods, sport drink mixes, baby foods and baked goods.
EXAMPLES
In order that this invention be more fully understood, the following examples are set forth. These examples are for the purpose of illustration only and are not to be construed as limiting the scope of the invention in any way.
Example 1 - Treatment of the Coconut Slurry
The starting material was 1000 kg of commercial grade white coconut meat (purchased as unsweetened ground material from a retail store; average particle size 3 mm x 0.5 mm x 0.5 mm).
The coconut meat (room temperature) was ground with water (at 35°C) at a ratio of 1 part coconut meat to 10 parts water (w/v) using a Szego mill. The temperature of the coconut slurry was adjusted to about 50°C with gentle stirring in an open beaker. The pH of the slurry was adjusted to a pH of 4.5 by adding 3M phosphoric acid.
Gamanase (Novo Nordisk, Denmark) was added as a liquid at a ratio of 2% of the coconut meat starting material by weight. The coconut slurry was maintained at 50°C with gentle agitation for 5 hours, followed by a non-agitation settling period of 15 hours at 50°C. The enzymatic product slurry was centrifuged using an IEC fixed head rotor at 9000 X g and the following four phases were obtained: (1) an oil phase (557 kg), (2) an aqueous phase (10,275 kg (protein content: 41.1 kg )), (3) a solid phase (170 kg (oil content: 110 kg; protein content: 24.8 kg)) and (4) an emulsion phase.
Example 2 - Separation of the Solid Phase
The solid phase obtained in Example 1 (representing 17% of the weight, 16.3% of the oil, and 14.6% of the protein of the starting coconut meat on a moisture free basis) was washed with water, centrifuged and freeze-dried. The freeze-dried residue was mixed with water at a ratio of 1 part residue with 15 parts water. The pH of the resultant solid layer/water combination was adjusted to 11.5 using 4.25M NaOH (15%>) and stirred for 1 hour at room temperature. Additional volumes of sodium hydroxide solution were added during this process to maintain the pH of the solid layer/water combination at 11.5. 88% of the protein contained in the solid layer was thus extracted. The undissolved solid residue (i.e., the coconut grate product) can be separated from the aqueous solution (i.e., the filtrate) that contains the solubilized coconut protein by, for example, filtration or centrifugation. The coconut grate product can then be dried (e.g., spray drying) yielding the coconut grate that will typically have a residual moisture level of about 9% by weight.
Once the coconut grate product was separated, the filtrate was then acidified with dilute HC1 to a pH of 4.5 to precipitate the protein. The protein suspension was gently agitated for 30 minutes to complete precipitation, then centrifuged. The solids were then dried (e.g., freeze-drying). 93.5% (20.3 kg) of the dissolved protein was recovered as an off- white, odor free solid.
Example 3 - Treatment of the Oil Phase
The oil phase obtained in Example 1 contained 2% moisture by weight. With this level of moisture, the oil phase should be vacuum dried at 80°C, under 50 mmHg residual pressure until the moisture content is reduced to about 0.05%> by weight. Because the oil was found to be of high quality, conventional refining was deemed unnecessary.
The oil phase obtained in Example 1 could also be passed through a short path distillation unit to remove volatile non-triglyceride components, thereby reducing the free fatty acid content (as much as to a final level of less than about 0.1%).
Example 4 - Separation of the Aqueous Phase
The aqueous phase obtained in Example 1 retained a pronounced, coconut aroma, a somewhat sweet flavor and low viscosity. This phase contained 43.1% of the protein content of the original coconut meat starting material. Freeze-drying of the coconut water concentrated the overall protein content of the liquid from 0.4%> to 1.5%. The aqueous phase can preferably be concentrated using reverse osmosis and/or ultrafiltration. The water that is retained from the concentration process is the recyclable water product and has few impurities in the form of residual protein and sugar molecules. The recyclable water product can be used for additional rounds of coconut meat processing.
While we have described a number of embodiments of this invention, it is apparent that our basic constructions may be altered to provide other embodiments that utilize the formulations and methods of this invention. Such embodiments are considered within the scope of this invention. Other embodiments are contained in the following claims.