GB2094334A

GB2094334A - Extracting oil, protein and flour from fresh coconut meat

Info

Publication number: GB2094334A
Application number: GB8129503A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1981-03-09
Filing date: 1981-09-30
Publication date: 1982-09-15
Also published as: DE3137449A1; PH20606A; GB2094334B; JPS57149398A

Abstract

A process for extracting oil, protein and flour from fresh coconut meat without boiling, refrigeration, action of enzymes, acidification, use of salt or brine, electrolytic action or shock waves includes drying the coconut meat at 60-70 DEG C to break coconut milk emulsion, grinding the dried coconut meat, pressing the ground meat to extract part of its oil content, mixing the residue with heated tap and coconut water at 55- 65 DEG C and further grinding into a finer size, mixing and agitating the slurry at 55-65 DEG C, separating the solid from the liquid, drying the solid to recover the flour content, separating further an oil phase from an aqueous phase to segregate the water clear coconut oil and water-protein slurry, processing the water clear oil into edible oil and processing the water-protein into protein powder. <IMAGE>

Description

SPECIFICATION Extracting oil, protein and flour from fresh coconut meat This invention relates to processes for the isolation of useful substances from vegetable sources. More particularly, it relates to a process for extracting oil, protein and flour from fresh coconut meat.

The conventional method for the recovery of oil from the coconut meat has not changed much during the past 200 years. This method involves the drying of the immaculately white, edible and clean coconut meat to dirty, unedible and brown copra for subsequent pressing in expellers to obtain the oil by mechanical action. The oil thus obtained is dirty, needing to be refined, bleached, filtered and deodorized. The residual copra meal is fit only for animal feeds. Proteins and flour are not recovered for human consumption and most of the proteins are eaten by the bacteria. About 30% of the oil content is lost in this process.

Studies made by the Tropical Products Institute (TPI) of England, concluded that the main stumbling blocks in the extraction of high quality coconut oil and protein from wet coconut meat, involve chronologically: a) optimizing coconut milk emulsion extraction from wet coconut meat; and b) breaking the coconut milk emulsion to separate the oil, protein and water.

TPI also noted "at least part of the cause of the economic failure of the modern wet processes must be attributed to the kinds of milling system used. These processes, which employ mills incapable of grinding the coconut the subcellular dimensions, will not achieve high extractions of oil and protein. The crux of the whole problem of wet-processing of fresh coconut, is the separation of the emulsion into its constituents. This cannot be done simply by boiling, as with the primitive methods, because a protracted boiling process would seriously damage the quality of the protein and of oil".

The aim of the present invention is to provide a method of extracting oil, protein and flour from fresh coconut meat taking into consideration the aforementioned problem areas.

Accordingly the invention provides a process for extracting flour, oil and/or protein from fresh coconut meat comprising: drying continuously the coconut meat at a temperature in the range 600C to 700C to break the coconut milk emulsion; grinding the coconut meat into the size range 80 to 100 mesh pressing the ground coconut meat to separate at least some of the oil content thereof from a residue; immersing and mixing the residue in heated tap and coconut water at a temperature in the range 550C to 650C; grinding further the immersed ground coconut meat to form a 200 to 250 mesh slurry; mixing and agitating the slurry continuously for from 1 5 to 20 minutes at a temperature in the range 550C to 650C; and separating a solid from the liquid in the agitated slurry mixture, whereby flour can be extracted from the solid and oil and/or protein can be extracted from the liquid.

When fresh coconut meat is dried at temperatures in the range 600C to 700C to less than 5% moisture content, oil separates permanently from water and protein without the need for boiling. Thus continuous drying of the wet coconut meat results in breaking or deemulsionizing the coconut milk emulsion. While this is a solution to the TPI problem (b) discussed above, it is conducted as the first phase in the process of my invention.

Cellular structures which hold the oil are ruptured and cut into two to five pieces when dried coconut meat is ground to about 100 mesh.

This enables a proportion of the oil to be extracted by pressing. Further mechanical grinding treatment by a grinder-macerator to grind the coconut meat residue to particles of about 250 mesh results in the cell walis being broken, thereby liberating the oil. In the process of the invention this additional grinding of the residue is performed in heated water so that most of the residual oil is released into the water. Thus almost 100% recovery of the oil from fresh coconut meat is achieved. These steps, the second phase in my invention comprises the solution to the TPI problem (a).

It has been found that a process in accordance with the present invention provides a means for extracting oil, protein and flour from the fresh coconut meat, wherein the products obtained through said process are fit for human comsumption without the need for further refining or processing.

It has been further found that a process in accordance with the invention is economical in terms of reducing the high capital and operating costs of the traditional recovery of oil by dispensing with some of the tradditional process steps and substantially simplifying the process.

It has also been found that a process in accordance with the present invention enables the recovery of solids of oil, protein, sugar and chlorides from coconut water.

Other features and advantages of this invention will become apparent upon reading the description and with reference to the accompanying drawing which is a process flowchart.

The process of the invention involves two main phases, first the breaking or de-emulsionizing of the coconut milk emulsion in the fresh coconut meat, and secondly the extraction of water-free coconut oil, protein and flour. The first phase, comprises the breaking up of the coconut milk emulsion, preferably also includes recovering the crude acid, crude tar, crude methanol and crude gas from coconut shells.

In the preferred embodiment, the shells of the coconut are removed and the fresh meat is chopped lengthwise, into about 20 pieces. The coconut water is stored in a stainless steel tank.

The chopped coconut meat is then washed with chlorine to check bacterial contamination during the pre-drying stage. Breaking or deemulsionizing of the coconut milk emulsion starts within five minutes thereafter in a pre-heated drier. The chopped fresh coconut meat is dried at a temperature ranging from 600C to 700C for about 24 hours until the moisture content is less than 5%.

The second phase follows the breaking or de emulsionizing phase. From the drier, the coconut meat is immediately ground to 80-100 mesh.

The ground coconut meat is then pressed to separate about 85% of its oil content. In order to minimize undue build-up of heat, this treatment should not be undertaken in an oil speller. The oil thus derived is stored in a storage tank. The residue is then immersed and agitated in a mixing tank with coconut and tap water and heated at 550C to 650Cforfive minutes. Preferably the weight of the coconut and tap water in the tank is four times the weight of the residue. The immersed ground coconut meat residue is then comminuted in a colloid mill or grinder/macerator, to produce a slurry of 200 to 250 mesh. The slurry is then transferred to a mixing tank which is provided with a heater at the bottom.In the mixing tank, the slurry is further mixed and agitated continuously for 1 5 to 20 minutes while maintaining the temperature at 550C to 65 C.

The agitated mixture is then conveyed to a solid-liquid centrifuge to separate the liquid from the solid which comes out in paste form. This paste is actually the wet flour. The wet flour is then dried. This may be accomplished in two ways-with or without the addition of tap water.

Without adding water, the wet flour can be dried in a suspension, pneumatic or splash drier.

Alternatively, after the addition of tap water, the wet flour may be dried using a spray drier. When this is desired, an amount of tap water, two times the weight of the wet flour and heated to 550C to 650C, is added to the wet flour prior to the drying stage. Drying occurs when the product is sprayed into a stream of warm air in spray drier, the influent air having a temperature of about 1000C to 1 500C.

The remaining liquid oil, protein and water obtained from the solid-liquid centrifuge is fed to a liquid-liquid centrifuge where the liquid is separated into an oil phase and an aqueous phase, the aqueous phase being a water-protein slurry. The oil thus obtained is deoderized with activated carbon to make it edible and is subsequently deposited in a stainless steel tank.

The water-protein slurry is allowed to settle in a settling tank for 30 minutes. About 20% by volume of the top portion of water is removed for recycling and recovery of more oil. Then 60% of the next or middle portion of water phase is discarded. The remaining 20% of water, the bottom portion, together with the precipitate, which is protein, is slowly dried, at a temperature of about 650C to 700C using a spray drier, to recover the water-soluble protein powder.

The flour and protein thus extracted may then be weighed and packed individually.

It has been found that in order to obtain maximum yields of oil, protein and flour, water used as a solvent must be pre-heated to 550C to 6500. This temperature is critical since it has been found that at a temperature lower than 550C, or higher than 650C a reduction in the quality and extraction rate of oil, protein and flour occurs. Air entering the enclosed processing area should be washed by means of a suitable air water washing machine to prevent contamination of the extracted oil, protein and flour by microorganisms such as bacteria.

Using a process in accordance with the invention it has been found to be possible to break or de-emulsionize the coconut milk emulsion in fresh coconut meat without boiling, refrigeration, action of enzymes, acidification, use of salt or brine, electrolytic action or shock waves.

It has also been found that more than 99% of the oil content of fresh meat can be recovered. It can be concluded therefore, that my invention has successfully hurdled the main stumbling blocks in the extraction of high quality oil, protein and flour from fresh coconut meat.

Claims

1. A process for extracting flour, oil and/or protein from fresh coconut meat comprising: drying continuously the coconut meat at a temperature in the range 600C to 700C to break the coconut milk emulsion; grinding the coconut meat into the size range 80 to 100 mesh; pressing the ground coconut meat to separate at least some of the oil content thereof from a residue; immersing and mixing the residue in heated tap and coconut water at a temperature in the range 550C to 650C; grinding further the immersed ground coconut meat to form a 200 to 250 mesh slurry; mixing and agitating the slurry continuously for from 1 5 to 20 minutes at a temperature in the range 550C to 650C; and separating a solid from the liquid in the agitated slurry mixture, whereby flour can be extracted from the solid and oil and/or protein can be extracted from the liquid.

2. A process according to claim 1, in which said solid is dried to produce coconut flour.

3. A process according to claim 1 or claim 2, in which said liquid is separated further into an oil phase and an aqueous phase:

4. A process according to claim 3, in which the oil phase is deodorized to produce edible coconut oil.

5. A process according to claim 1, in which a protein precipitate in said liquid is allowed to settle out.

6. A process according to claim 3, in which a protein precipitate in said aqueous phase is allowed to settle out.

7. A process according to claim 5 or claim 6, in which said precipitate is dried to obtain a protein powder.

8. A process for extracting flour from fresh coconut meat comprising: drying continuously the coconut meat at a temperature in the range 600C to 700C to break the coconut milk emulsion; grinding the dried coconut meat into the size range 80 to 100 mesh; pressing the ground coconut meat to separate at least some of the oil content thereof from a residue; immersing and mixing the residue with heated tap and coconut water at a temperature in the range 550C to 650C; grinding further the immersed ground coconut meat to form a 200 to 250 mesh slurry; mixing and agitating the slurry continuously from 1 5 to 20 minutes at a temperature in the range 550C to 650C; separating a solid from a liquid in the agitated mixture; and drying the solid to produce coconut flour.

9. A process for extracting oil from fresh coconut meat comprising: drying continuously the coconut meat at a temperature in the range 600C to 70"C to break the coconut milk emulsion; grinding the dried coconut meat into the size range 80 to 100 mesh; pressing the ground coconut meat to separate at least some of the oil content thereof from a residue; immersing and mixing the residue with heated tap and coconut water at a temperature in the range 550C to 650 C; grinding further the immersed ground coconut meat to form a 200 to 250 mesh slurry; mixing and agitating the slurry continuously from 1 5 to 20 minutes at a temperature in the range 550C to 650C; separating the solid from the liquid in the agitated mixture; separating further an oil phase from an aqueous phase liquid; and deodorizing the oil phase to produce edible oil.

1 0. A process for extracting protein from coconut meat comprising: drying continuously the coconut meat at a temperature in the range 600C to 700C to break the coconut milk emulsion; grinding the dried coconut meat into the size range 80 to 100 mesh; pressing the ground coconut meat to separate at least some of the oil content thereof from a residue; immersing and mixing the residue with heated tap and coconut water at a temperature in the range 550C to 650C; grinding further the immersed ground coconut meat to form 200 to 250 mesh slurry; mixing and agitating the slurry continuously from 1 5 to 20 minutes at a temperature in the range 550C to 650C; separating the solid from the liquid in the agitated mixture; allowing the waterprotein slurry to settle to obtain a precipitate; and drying the precipitate to obtain the protein.

11. A process for extracting flour, oil and/or protein from coconut meat, substantially as herein described with reference to the accompanying drawing.

12. Every novel feature and every novel combination of features described herein.