LU83441A1 - PROCESS FOR TREATING OILS AND FATS AND PRODUCTS THUS OBTAINED - Google Patents

Description

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The present invention relates to a process for the biological treatment of crude, animal or vegetable, animal or vegetable oils and fats, as well as to oils and! fats thus obtained.

It is well known that almost all oils and fats, in solution or in suspension, contain non-lipids and phosphatides. For simplicity, the terms "non-lipids" and "phosphatides" will be repeated below under the more general term "non-glycerides", following the classification of "Bailey's Industrial Oil & Fat Products" 4th edition, 1980 , Volume 1, pages 45 to 83, edited by Daniel SWERN, Wiley Interscience Publication, New York, USA. These can be present in appreciable quantities, as for example, in: Kad.té butter, Illipé oil, certain marine hils such as sperm whale spermacéti, certain crude animal oils and fats such as dehydrated butter , chicken fat, etc .; but often these non-glycerides are in the state of low concentration, even of traces, but nevertheless having a marked inhibitory effect on the treatments (for example a negative effect on the crystallization) or annoying for the finished products (for example, a negative effect on the clarification of oils), as can be the case for oils of sunflower, cotton, olive pomace, etc.

It is well known that the "impurities" in the treated oils have a harmful effect on operations and yields! refining, which is why the neutralization or deacidification of oils is generally preceded by a prior "degumming / Γ - 3 -. Similarly, in fractionation by crystallization, the presence of non-glycerides, may even have the state of traces, a marked inhibitory effect on the crystallization of oils and fats.

Among these non-glyceridic and often inhibitory substances contained in oils and fats, especially in crude oils, there is first of all the phosphatides. Phosphatides, the most common of which are lecithins and cephalins, are triglycerides in which one of the acyl radicals (-CO-R) is substituted by phosphoric acid, itself being saturated with a basic group, for example choline or the chola-mine. Phosphatides have a notable emulsifying and anti-crystallizing power.

i i Among the non-lipids contained in oils and | fats, we can note: - carbohydrates or carbohydrates, classified into two main groups, monosaccharides and polysaccharides. Monosaccharides, such as glucose, galactose, etc., generally exist in oils and fats in the form of sugar-phospholipid complexes I (for example inositol which is a combination of phosphatide and galactose, or else phytosteroline, composed of phytosterol and glucose). The polysaccharides, mainly the polyholosides (gums, cellulose, ...) which, in | as high polymers, are insoluble in water or provide cohoids. These polysaccharides can hydrolyze until complete degradation into monosaccharides. Some are soluble in hot water (glycogen, starch and pectin) but. / j: ψ! I · - 4 - i ι I can form gelatinous masses; } ij - certain simple proteins (gelatin) and compounds (casein) il j as well as certain degradation products (peptones, proteoses) which can be dissolved in oils and fats! in particular if the oleaginous seeds and fruits or the animal tissues from which they come have been damaged by a hydrolytic decomposition before their extraction; - certain resins, waxes and various mucilages; - sterols of all kinds; - carotenoid pigments, etc.

Although most of the phosphatides and non-lipids in general, found in oils and fats, are eliminated during neutralization with alkalis, these substances foreign to the oil or to the fat itself. even thwart the effectiveness of treatments, especially during centrifugation, filtration, crystallization, fractionation, win-terization and clearing.

One of the essential aims of the present invention consists in remedying the aforementioned drawbacks of existing oils and greases, and in providing for an industrially and economically valid process making it possible to obtain oils or greases which are clearly "cleaner" and of viscosity. lower than the oils or fats treated according to conventional methods, in particular during the various abovementioned operations to which the oils or fats are subjected.

To this end, the process according to the invention consists in adding to the oil or grease to be treated, at least one enzyme / making it possible to hydrolyze and / or depolymerize the components / ^ /.

- 5 - non-glycerides contained therein.

According to a particular embodiment of the process of the invention, the enzyme is added before the operations of centififugation, filtration, crystallization, fractionation, wintering or clearing of this oil or fat.

According to a particularly embodiment! preferred of the invention, the enzyme is chosen from the group comprising phosphatases, pectinases, cellulases, amylases, gumases, proteases and mixtures of two or more of these substances.

The subject of the invention is also the oils and greases obtained according to the process described above.

Other details and particularities of the invention will emerge from the description given below by way of nonlimiting example of some particular forms of the invention. As already follows from the above, the present invention proposes to deal oils and fats beforehand, by means of appropriate enzymes, so as to greatly improve the operating conditions such as centrifugation, filtration, crystallization, fractionation, wintering or clearing. Thus, if the conditions of crystallization of an oil or fat are greatly improved, the conditions of filtration are automatically improved, or else this filtration is simply made possible. Likewise, if good crystallization is essential, during winterisation and fractionation operations, it essentially depends on the "cleanliness" of the treated oil. Fractionation is the progressive cooling (cooling) of a fat, followed by separation of the crystals, with the aim of obtaining two fatty phases at different times. Winterization is the freezing of a liquid oil I, followed by a separation of the crystals, with the aim | to obtain, by filtration or centrifugation, a clear main phase. Among the industrial sintering and fractionation processes, mention will be made, for example, of the crystallization and filtration processes described in Belgian patents No. 713,430 and No. 713,330. The clearing is an operation of polishing the oils, retaining the haze, impurities and mini-crystals present in the oils, on filtering surfaces, so as to make them clear and shiny.

Enzymes are proteins with a powerful and very selective catalytic effect. In fact, each enzyme has the property of specifically catalyzing an organic reaction via the formation of an enzyme-substrate complex. It has thus been found, according to the invention, that a certain number of enzymes specifically attack the non-glyceridic components of various oils and greases; because of the very nature of this component.

Among the enzymes specifically active in this field, mention will be made, in particular, of phosphatases (phospholipases-C), which attack phosphatides and pectinases, cellulases, amylases, specific to the various carbohydrates and gumases, specific to plant gums and mucilage; proteas ”which hydrolyze proteins (gelatins and caseins). Lipases of the pancreatic type, attacking the glycerides themselves by hydrolyzing the fat, are not part of the field of enzymes, which are useful for the treatment of non-glyceridic components. / "/ l! - 7 -

Given the complexity of the non-glyceridic residues of certain oils and fats and the specificity of the proper action of enzymes, it may be necessary to use several enzymes together. Moreover, it often happens that the commercial "enzymes", whether they are of animal, vegetable or microbiological origin, actually contain several enzymes with different specific actions. Thus, for example, papain and ficin, products extracted from the fruits of the papaya tree and the fig tree, contain at the same time proteases, phosphatases and peroxidases. Similarly, care should be taken to avoid using enzyme complexes for oils and fats, some of which could have negative effects, for example by producing oxidations or hydrolyses in the oil or fat itself.

According to the invention, the techniques for treating oils and fats which can carry out, by the enzymatic route, the hydrolysis and / σα the depolymerization of the non-glyceridic components which they contain, are of three orders: mixing in oils and fats, of enzyme or enzyme complexes previously dissolved in a small quantity of suitable solvent (for example water, optionally packaged, propylene glycol, i S etc.). A large number of solvents are possible, but a non-toxic solvent suitable for the enzyme will be chosen; i miscible with the oil or fat to be treated. This addition can be done both in the treatments by successive loads as in the continuous treatments. The necessary quantity of enzyme (s) to be added to the oils and fats ^ / ïï - 8 - according to this process, can range, depending on the enzymes and the products to be treated, from 20 to 400 ppm, that is to say from 0.02 kg to 0.4 kg of enzyme per 1000 kg of oil or fat, and preferably from 50 to 200 ppm, i.e. from 0.05 to 0.2 kg of enzyme per 1000 kg of oil, these values being understood as concentrated enzymes, that is to say without diluent or solvent.

2) the passage of the oil or the fat through an enzyme filter bed ^) fixed (s) or "insolubilized)" on solid or semi-solid supports, preferably having a porous or fibrous structure. In this technique, the enzymes are trapped in the micro-cavities of the porous or fibrous structure of the substrates. These substrates will consist, for example, of resins or synthetic polymers, cellulose carbonates, gels such as agarose, filaments of polymers or copolymers with a porous structure, trapping in their cavities fine droplets of enzyme. in solution. In terms of enzyme concentration, we can go as far as the saturation of the supports.

3 °) The dispersion of oils and fats in the form of fine droplets, in a dilute enzymatic solution, preferably containing from 0.2 to 4% by volume of enzyme. This technique is described in particular in Belgian patent n ° 595.219. A cylindrical column several meters high with a conical cover is filled with a dilute enzymatic solution. A non-toxic and immiscible solvent in the oil or fat to be treated, preferably water, will be chosen for this purpose. The bottom of the column is equipped with a distributdem system! - 9 - in which the oil or fat is injected continuously in an extremely divided form (approximately 10,000 flows per 2 m). An infinite number of droplets of oil or fat are thus formed, which rise slowly in the enzyme solution and meet on the surface, to be evacuated continuously at the top of the conical cover of the reactor.

! In all these techniques, it is important to respect the concentration, temperature and pH conditions which allow the enzyme to give its maximum catalytic effect. To this end, according to the invention, the enzymatic reaction | . will be done at a temperature between 10 ° and 65 ° C, and preferably

i rence at a temperature between 15 ° and 30 ° C, and at a pH

i - I i of the order of 7. This is particularly important for concrete fats, for which we will choose enzymes j stable at the temperature where the fat is perfectly melted | In general, the enzymatic reaction is allowed to continue for a period of time making it possible to obtain the practically total hydrolysis and / or depolymerization of the non-glyceridic components contained in the oil or the fat.

j However, it may be necessary to stop at the end of j; treatment, the effects of the enzyme, by adding an inhi'oan or t; simply by heat, for example by heating to a temperature: at least 85 ° C., insofar as the reaction en2 / me qu! could continue undesired (for example with n oxidizing or hydrolyzing effect on oils and fats i Π themselves).

ij According to the invention, a typical example of the ap :: _ß. ~. / -location of the process for the treatment of non-glyceridic components of oils and fats by the addition of enzymes is the treatment with crude palm oil by pectinase, in order to allow crystallization and fractionation thereof without subjecting it current refining operations.

For the past twelve years or so, fractionation by crystallization of palm oil has taken a very important place in the treatment of this oil. More than a quarter of the palm oil produced in the world (estimated at 4,682 thousand tonnes for 1980-81 - J.A.O.C.S. January 1981) is marketed in the form of its liquid and concrete fractions.

! In Malaysia, more than 30 industrial units practice the fractionation of palm oil. In Indonesia, 3 factories are sufficient to fractionate half of the country's palm oil production. But all of these palm oil fractionation workshops are installed in oil refineries, as one of the stages in the refining operations. There are currently none installed in the oil mills of plantations producing crude palm oil. The reason is that, while the crystallization of a refined oil is relatively easy, it is extremely unsatisfactory, and often impossible, in the case of a crude palm oil.

. This is because, in addition to free acidity (FFA), crude palm oil contains phosphatides and non-lipid components, generally referred to as "mucilages" 1 or "gums", which, although 'seemingly insignificant (0.2 to 1% of the crude oil), have a detrimental detrimental effect on the crystallization of the crude oil. This is why, before any other operation, the crude palm oil is generally subjected to a prior "degoirunage". This degumming generally consists of an attack of the crude oil with a concentrated solution of phosphoric acid (0.05 to 0.2% by volume), which more or less attacks the gums by precipitating them so as to retain them during subsequent filtration on active soils.

But degumming crude palm oil with phosphoric acid has many drawbacks. Unless careful, concentrated phosphoric acid (85%) also attacks the oil itself, causing partial degradation of the oil by formation of phosphate residues. In addition, the precipitates formed in the oil must necessarily, before any other operation, be filtered and retained by a sufficient quantity i i i of active earth. Hence a new loss of oil, j the land retaining the oil up to about 40% of their own pcüs. The palm oils thus treated on the land undergo significant discoloration which prevents them from being considered as crude oils, which often has a significant effect on the customs duties of importing countries (in 1981, the difference in duties in the EEC was 10% of the value of imported palm oil). Finally, phosphoric acid imparts to the treated oil an extremely troublesome, or even inhibiting, mineral acidity for the crystallization itself. This is the reason why certain processes "neutralize" traces of unreacted phosphoric acid in oil, for example, by

Ide of sodium hydroxide or calcium carbonate. However, this neutralization has the disadvantage of giving rise to soaps, sodium or calcium, which are powerful inhibitors of crystallization. These soaps must therefore be retained in turn on active soils, with the drawbacks exposed above.

The treatment of crude palm oil with enzymes avoids the drawbacks mentioned above. The enzymes have an absolutely specific action on the oil: the pectinases, for example, will selectively hydrolyze the pectins, numerous in crude palm oil, especially since the introduction into the oil mills of high-performance continuous presses, extracting with l oil part of the components of vegetable fibers. Enzymes have the enormous advantage of acting on oils, which are delicate biological compounds, without violent acidification (the pH specific to enzymes is around 7) and at exceptionally moderate temperatures, the enzymes having their activity at temperatures very close to ambient temperatures. The enzymes leave the crude palm oils with all their crude oil characteristics and make it possible to fractionate them, without loss of material, at the level of the oil mill, without all the equipment costly in investment and production costs. the oil refinery.

To illustrate the invention more concretely, two examples of treatment, one carried out with phosphoric acid (comparative example 1) and the other according to the invention (example 1) on a crude commercial palm oil, having a "free" acidity of 4.94% FFA and an iodine index of 52.98, are given / below. / 1 /

(I

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: Comparative example 1.

Initially, this palm oil was subjected to 14 successive fractionation tests, either as such or after various treatments, such as centrifugation, washing, attack with phosphoric acid and partial discoloration with active earth (2% of Tonsil FF optimum), but always avoiding neutralization of the oil. All these tests were negative, the crystals formed being extremely small (0.02 to 0.15 mm .: in diameter), shapeless and without consistency, in a very viscous liquid suspension.

1 Example 1.

According to the invention, the following test is carried out: | A - Enzymage;

A load of 30 kg of crude palm oil is heated to + 50 ° C. 1% solutions in distilled water of Celluclast 2 enzymes, 0LfceUuLase) are prepared and ULtrazym.lOO (pectinaæ) βοή adds 600 g of each of these aqueous solutions to the oil, with vigorous stirring for a few minutes. The oil is then kept at + 50 ° C, with moderate stirring, for a total reaction time of two hours. Then the temperature is raised to + 90 ° C to deactivate the enzymes and prepare the mixture for filtration. The oil is dried under vacuum and filtered with a filter aid (Celatom).

B - Fractionation: The crude enzyme palm oil is subjected to normal crystallization, by heating to 68 ° C followed by controlled cooling. Excellent crystallization is obtained ^ i-! "/ - - 14 - as a majority of very firm and rounded crystals of 0.5 to 0.9 mm in diameter, with some medium or small crystals.

Then filtered on a vacuum filter, the oil thus crystallized filtered in 16 to 22 seconds, leaving a very dry stearin cake 12 mm thick and a very liquid and shiny olein.

The crystallization tests were repeated several times, with the same success.

For this purpose, we will compare the attached Figures 1 and 2 which respectively represent the photographs taken under stereoscope, in polarizing light, respectively of the crystals obtained according to Comparative Example 1 (magnification 30 x) and of the crystals obtained according to Example 1 of the invention (magnification 20 x).

It is understood that the invention is in no way limited to the embodiments described and that many i

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i modifications can be envisaged without departing from the scope of this patent.

"; In fact, a large number of oils and greases containing non-glyceridic components which can usefully be hydrolysed or depolymerized to improve their performance during treatments by centrifugation, filtration, crystallization, fractionation, winterization and clearing, and also seen the large number of enzymes whose specific action may be useful for the same purpose, it is obvious that the examples could be multiplied, each of oils and fats and each of enzymes being a case in point.

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Claims (16)

1. Process for treating a crude, semi-processed or refined oil or fat, animal or vegetable, characterized in that it consists in adding to this oil or fat, at least one enzyme making it possible to hydrolyze and / or depolymerize the non-glyceride components contained therein. 2. Method according to claim 1, characterized in that the enzyme is added before the operations of centrifugation, filtration, crystallization, fractionation, wintering or clearing of this oil or fat. * 3. Process according to either of Claims 1 and 2, characterized in that the enzyme is chosen from the group comprising phosphatases, pectinases, celluases, amylase islands, gumases, proteases and mixtures of two or more of these substances. 4. Method according to any one of claims 1 to 3, characterized in that the above treatment is carried out by adding the enzyme in the dissolved state in the form of a solution in a non-toxic solvent, miscible with the oil or fat to be treated, under conditions of intense agitation. 5. Method according to claim 4, characterized * in that the quantity by weight of enzyme per 1000 kg of oil or fat is between 0.02 and 0.4 kg. 6. Method according to claim 5, caraEterized in that the amount by weight of enzyme per 1000 kg of oil or fat is between 0.05 and 0.2 kg. ^ / - 16 - 7. Method according to any one of claims 1 to 3, characterized in that the above-mentioned treatment is carried out by passing the oil or the fat over an enzyme filter bed fixed on a solid or semi-support. -solid. 8. Method according to claim 7, characterized in that the support has a porous or fibrous structure. 9. Method according to any one of claims 1 to 3, characterized in that the above-mentioned treatment is carried out by dispersing the oil or the fat in the form of fine droplets, in a dilute enzymatic solution, the solvent used for this purpose being non-toxic and immiscible in this oil or fat. 10. Method according to claim 9, characterized in that the enzymatic solution contains from 0.2 to 4% by volume of enzyme. 11. Method according to any one of claims 1 to 10, characterized in that the enzymatic reaction is allowed to continue for a period of time allowing the hydrolysis and / or the practically total depolymerization of the non-glyceridic components to be obtained. 12. Method according to any one of claims 1 to 11, characterized in that the enzymatic reaction is carried out at a temperature between 10 ° and 65 ° C and at a pH of the order of 7. 13. The method of claim 12, character ized in that the enzymatic reaction is carried out at a temperature / between 15 ° and 30 ° C. / 1 / T t - 17 - 14. Method according to any one of claims 11 to 13, characterized in that after the hydrolysis and / or the practically total depolymerization of the non-glyceride components, the fat or the enzyme oil are heated to a temperature of at least 85 ° C, or an inhibitory substance is added thereto, so as to deactivate the enzyme or enzymes. 15. Process for the treatment of crude, semi-processed or refined oils and fats, animal or vegetable, as described above, in particular in Example 1. 16. Oils and fats, in particular palm oil, treated by the process according to any one of claims 1 to 15. Drawings: A— boards -JI.- psge.3 of which ........ A. .... r ^ cc de rr-rde ... A3 ......: sd î description .......... 3 - "'' ·" · - es claims .... .... description Luxembourg, Charles München