HUE035623T2 - Method for reducing the 3-mcpd content in refined vegetable oils - Google Patents

Description

METHOD FOR «EDUCING THE 3-MCPD CONTENT IN REFINED VEGETABLE OILS ©tsseripriw

The invention rotates to a precess for reducing tits 3-munpchlO'ropropaue~l,2-dlot content i« νΐΐι\ί\'Λ ! ' ct wm \ < v « ' <O mx ueaurooxd 4 »« k » deauxnmeu od, «{»

At. t sk t 1 }\ * ί \ o x" η» , n i v hleacneo »ή t tu, ακ -xiitax e,nth !\ w/pmatcP ni”>s5i He u'tRU x'd »- <w t-- cnc a OitCi od. and the niun .»d is deedoovd

In die industrial production of oils and Hits, bleaching earths are used for removing turbidity, discoloration or else for removing oxidation accelerators. Taste, colour and storage stabilily of the oils and fats can be signdtcantly improved by the adsorptoe purification. Various classes of bleaching earths are used for purification. Λ first group foons the class of highly active bleaching earths which are usually based on montmoritlorrite tllFEE high performance bleaching earth).

In m up ounpt w'» > x. t R o \ x ο,ο ' utmost ! > > 's w t -. r < m <\ d >'» i\ g carried out so a complicated process by dealuminiziog the crude clays by means of concent rated acids at high temperatures, usually at the boiling point. This process gives a bleaching earth product having a very large spec-tie surface area and large pore volume. The use of even small amounts of ibis highly aettve bleaching earth leads to appreciable petrification of the crude oils. The use of smalt unmunw sn the blvaehsng process ss therciore dvsuahie be-muse the used pleaching η-Λ t-, \ ^"ds ς->ιΐιυ ,fi or s. >ti ι«λ ihaioil Mrt ecr-.es Hr -sc ntd seco d,s the used bleaching earth has to he disposed of according io applicable regulations. A disadvantage of these highly active bleaching earths is the fact that large amounts of acidic salt-rich wastewater arise during the production process from the dealnminatlon by nacans of acid, and these can be treated os disposed of only In complicated proceases. The high e<-sts lot disposal of the wastes and also the complicated production process bring about the eompawbP high price of such >ghis -. R-. 1!'r u v v nth, A further group forms the class of natural active clays (NAEH ::: natural active bleaching earth). These naturally occurring bleaching earths have been used for hundreds of years for purifying fats and oils These oat'-mU sense systems t dss RvArrcd tu vs 1 oilers eaos ot bullet earlhst can tv. made available very inexpensively. However, they have only a low bleaching power so that they are usually not suitable for purifying ddbcuh-to-b.leach oils and fats. Furthermore, significantly larger amounts of the adsorbent compared to highly active bleaching earths have to he used in order to achieve the desired bleaching result. However, higher losses of oil or fat have· to he accepted as a result since the bleaching earths cannot he separated off in pure fortn and pertain amounts of oil or fet remain in thn bleimbihg earth:.

The third bleaching earth class, namely surfacmactivated systems (SMBE ~ surface modified bleaching earth; surface-activated bleaching earths). tepresents a eontprom.be 'between low production costs and acceptable activity. Here, a natural active raw clay is treated with small amounts of acid and "in-sltu activation*' is thus achieved. Raw clays containing attapnlgste and honnile have been found to he particularly useful for this process. These have a quite high specific surface urea for natural raw clays of from about 100 to 180 mVg and a pore volume of from about 0.3 to 0.35 ml/g, However, since salts formed in the acid activation or unreacted proportions of the acid are not washed out these -cumin ·?·· the product and me at least sometimes also deposited m the pores. As a result, these acid-activated blenching earths generally do no; attain the sums efficiency as is achieved by highly active bleaching earths t'HPBEi produced by dealumination hv 'vA'sxv R'd Ih'Aiw tin sen us <n > <Oo ot^es s nx>. <om o' d sds ewmp >ixhx<>' possible, and, as a particular advantage:, no acidic wastewater is obtained.

The OMfUc ('*dry milled bleaching earth") represents a-subgroup of the SMBBs, For the production of 8MBt\ the raw clay is generally treated with an aqueous solution of the acid. In the case of the T>MBV, t> solid acid, usually citric acid, is used for the activation and the solid acid is milled together with the raw clay, f 8 \00~ >7U desmibe» a pft\t"w Io' bieaUuno cd<-, wheiein i \hri> xoinpnstug the od m h< bleached, a neutral bleaching earth and a ehelnfing polyhmnc carboxylic acid is produced in a suitable vessel, the carboxylic acid has an even number of carboxyl groups, with the carboxyl groups being arranged in pairs and the carboxyl groups of each pair being able tit assume an cc I ipsed confirmation. US 5,151,311 claims a bleaching earth composition comprising a neutral bleaching earth which comprises attapulgiic and smectite in a ratio in the range from 0.3:1 to 1.5:1, with the proportion of mtupehne ,md smevhte xoruwpomeeg m a te.wt lw weight ot the Pleadnng emt't I he composition additionally contains a poiybasic carboxylic acid having an even nonsbei of carboxyl i<n swuu'ai' uunoC m ffiu with hAiko mo ' \ndt <<we hunt no e to ;s <i" »' ec 11 psed arrange men t. t'h c«,'<40 ''ho Hi dainb a bLmrnrw ,a;th eommwst on winch comps i mix:me c; a putseuhne cl λ an I c smoeahu o< bhn-ic unbcsd'C awd w m ,h' >mro> wise a wt luo eg a nU, n the t m\ from i Io 7 and being essentially free of sabs of mgamc acids. The clay has a moisture content of not more than 8% by weight, based on, the elm furthermore, the poiybasic carboxylic acid is ' \ , I ' ,'Νμ \ Λ ,. » ' T "t 0 '" '. 0' v - At t \\ " «i« oornposftion. US 6,34o,28o Bi also deserlbes a bleaching process in which the oft to he-bleached is brought into contact with tt prnllculhte eenipo§IHeb cotpprfeng particles of a clay mineral anti particles of at least one organic acid, with the organic acid being substantially ftee of safe of the ' tiu.'tfexU η o m\i η s n n< \ ιν'υ! > « no*

After bleacbrng, the u tmed oil should satisfy partictdar requirements in respect of colour,taste anti shelf life, Thu», the of; ososi not bo too dark and, depending on the type of oil, have a yellow to green colour Shade Imnhermore, the oil should be able io be kept without a deterioration in taste, ike, not taste raoeM, orer a prolonged period of time. U&amp; 7,179,491 Bi describes a process lot bleaching oils, which process does not requite any begemming of the oil or the use of alkali or other chemicals sueh as acids or bases, 'The oil Is obtamed iron', marine sources, mammals or fish. The crude oil Is: firstly degassed under reduced pfcssnre. After the vseaupt has been broken by means of gaseous nitrogen, silica is firstly added io the oil and vacuum is again applied to the reactor, The vaeuinh is broken ago in and bleaching earth is added to the mixture. After vacuum has again been applied to the reactor, the uuxture is bleached. The vacuum is broken again and the solid eopstituents are then separated off from the bleached: oil by filtration,. WO 201)6/052974 At relates to seco od emnpoMUotw containing iinoleic acid,- A proecss for refining crude sail In which the crude -w ,· devnmmed by addition of water or alternatiyely of phosphoric acid and/or citric acid is described The degutnmed oil tsr bleached: by adding bleaching agents snob as bleaching earth to the heated degnmmed oil US 4,939,115 A describes a method for removing phospholipids and impurities sueh as metal ions Ca. Mg, be and Co In oil. Here, degumming using 1% of water firstly takes place at ?ftsC, Bleaching of da; degutnmed oil is carried out using amorphous silicon oxide, WO 2006/131136 AI discloses a process tor refining tats and oils, wherein the crude oil is subjected to bleaching by being treated with a bleaching earth product containing a raw day. The crude oil is also introduced into a dcgnnnrung stage which can comprise preliminary degunoning by means of water and also acid deguanning.

In the treatment customary at present, the oil is, after pressing, firstly degassed and dried in order to remove, for example, dissolved oxygen. Mucilaginous materials, in particular phosphoiipids, are subsequently removed. I'or this purpose, the dried and degassed oil is sdnosed wnh phosphoric acid and stirred at about 95A? at atoaosplieric pressure for from about 15 to 20 minutes. in order to be able to separate ob the mncftngiuetw ut,Uen.fts moo teafttiy, tiufttei ’.sates w added, tot example in a proportion of 0.2% by weight, towards I he end of the. After brief stirring, the feciftfirt phstae is separated off. for example by cositrifttgatiop. The subsequent blenching of the de-gutumed oil cornprlses two stages, wet bieachlng and vacuum blouohing. For wet bfesehing, the degtunmcd oft is admixed with from O.t to 0.5% by weight of water artd. idler the oil its? Deen heated to ^'V, from 0.3 to 2¾ by weight of bleaching earth Is added. The mixture is then stated at atmospheric pressure for about 20 minutes. Vacuum (for example .100-mbar) is subsequently applied-and the oft is stirred at 95CC for another 30 minutes. After bleaching, the used bfoachfog tarth is separated off, for example by tillering the mixture through a filter unit provided, with a paper filter.

After bleaching, the oil is additionally deodorized For this purpose, supes heated stsatu having an -exit temperature of about 240*C is passed through the oil in order to remote Itte tatty acids and also unpleasant flavours and odours Deodorlzation is carried out under a reduced pressure in the range of less than 5 mbar, preferably from I to 3 mbar.

After refilling, the oil has to satisfy partieniar requirements in respect of for example, colour, taste and shelf life. For example, the oil should not -appear Frown but, depending on the type, have a-yeliow to green colour shade. A ntc.wmo ot tfo\ b the Lox found colour number red, which should he as low ns possible In order to smseuw the she'd' bfe the oil should have a very low iron or phospboiu\ .onto'i r.’txw, turn fo ' dd i < w'<w to<, <b petiole ,e 'wdn»^ uuu for to prevent development of a rancid odour and taste.

Apart iron· the type of blenching earth used, the process eundittons during degununing and during bleaching also have a significant influence on the result of oil refining, Thus, DE 10 2096 035 Odd At describes a process for bleaching oils and lots, wherein - a erode oil obtained irotn a vegetable or animal source is provided; - the crude oil is heated to a tempefntufo in the range from 35 to 55CC; - a bleaching earth is added to the heated crude oil; -> the heated crude oil is bleached; and - the bleaching earth; Is separated oft from the bleached crude oil, iks nixt A)uk\, i p<w\ i, ie i I w < mIo <. olon nuntb'ts to I tie se t ο, no fbc owc »<f addui.'it ot the Ptcnctnog <artb at t' nude; othern Be identical conditions, ! e at the some amount >9'bleaching earth added and the same bten.huse, conditions fbut, a \nuftiet amount ot He,idling earth o nitYicmut tor ,-ei wxme, a gwen eoh'tu o; the cm m the tdeuclnug opemuor;. Che ptoctss h,B me anvurbu"? mm the oft does n"t ivwe to be heated to high tcmpc;.uit;cs for addition of the bleaching earth and the amount of bleaching earth can also be reduced,

Hewever. undesirable accompanying materials which can be iwoifi-d ie health whenconsumed by human bcittgx e,m ako be ptoduved dorms en tefonug 3-Monochloropropane'L2'diol t'LMCFD) can be formed in the production of foodstuffs, e,g. in the production of soya sauce, during baking and toasting and aiso in the refining of vegetable oils and fats. In animat experiments, 3»MCPf> has been found to be carcinogenic- In addition, mutagenic properties of 3-MCPD have been observed f« v.’/ro but not /« vn;o. Furthermore, there are aiso indications that 3--MCPD impairs the tertihty of mam mots. .F'.MCPi.) can be present both in free or in bound form, for example in the form of an ester- in food.,ruth- Pit h.B been i'ovu t m stooes \m< ond ed-< lltv οοονοηοοηοη so repetabk bn,,

end oils can extend into the range of several hundred through to several thousand ppm. in each ease calculated as free 3-MCPD. The mechanism by which 3'MCPD is formed In.-refining ef fats and oiks has rsot yet been fully elucidated. However, in modelling studies, it has been found that chloride tons .and also glycerol and monoglvcerides. diglycerides and triglycerides are possible as oetenttai ''art eg οοοογ.<ο> m d e Imnnsmo -t ' Mt'EH

Limit values for the content of 3-MCPD in various foods have already been prescribed in the EU. Thus, a maximum of 26 ppm of 3-MCPD are allowed to be present in soya sauce or hydrolysed' ' opr Subic protenw \ mkeuok conk uFuho GPI; of 3 ouesomms pot ktb'ptao. ot t-v.k we’gln has been sot down for human beings by the scientific expert committees of the EU and the WHO/FAO,

It was an object of the present invention to provide a process for refining oils- which comprises-firstly degumming a etude -oil so as to give a degummed oil, admixing the degummed oil with a bleaching earth and bleaching it, giving a bleached oil, separating the bleaching earth iron? She bleached oil so as to give a filter oil, and deodorizing the fitter oil, which leads to a very low hnmalinn of u-MCED

This object is achieved by a process having the fo ituteu of Cktint 1, Advantageous embodiments of the process of t he invention are subject'mattes ot the dependent claims. 1st the process of the invention, the dogumming of the crude oil is -carried out using only water without addition of acids. The oil is sobssqtseofiy bleached ax a temperature 1st the- range front 86 to 100'C p?ou!ubk at a ten.peouure ot about <4o'\ p has w;tp?fsmgly boon round that legmnnung has a significant influence on the concentration of the 3-MCFO formed in she refining of oils and fats, while bleaching exerts a significantly smaller Influence and the concentration of 3-MCPD in the refined oil or fat after degnnamlng Is reduced by the addition of bleaching earth. This- was particularly surprising because even when using highly active bleaching earths (HFBEt, which are produced by extraction of raw clays with hydrochloric acid and therefore contain, chloride iocs, loom e-'ucenh ado,05 '-Mt'FP note found than ade- dcg.iOU"u^ sod -nth; xpww oicaJum,, >>f the degummcd oil, without bleaching earth having been added during bleaching. The inventors assume that precnt-mrc of 7A<CFD are formed during degurmrnog arid arc then converted Into '% MCPD during doodod.’unon

The invention therefore provides, a process for reducing the 3-inonochioropropatte-l ..3-died content in refined vegetable oils, where a crude ml is firstly degununed so as to give a degurnmed oil, the degummed oil Is mixed with a bleaching earth. and bleached, giving a bleached oil, the bleaching garth is separated from the bleached oil so as. to gne a filter oil. and the filter oil Is deodofiged, wherein; · water Is added to fhs erode oil for degumniihg and dogumuting is carried out without· addition of acfd at a temperature· of less than ?0"C, and the degononed oil Is pneferahiy separated offfiom an aqueous phase, - the degunnned oil Is heated to a temperature In the range front -SO to lOOX and the bleaching earth w added tn an amount of more than 1 b\ ocpdtt to the heated detnuomed ml, and - the bleaching is carried out at a. temperature in the range from 80: to 1 00X, in the process of the Invention, a crude oil is firstly provided in a customary way, This ca»: be obonned, tor example, b> ptesfing ό m oil null, fee etude od %.au afio be dega-wed -uni di led tn the usual way.

The etude oil Is then mixed with wafer and stirred at a relatively tow teurperntrn-e,

The-degummmg is preferably carried out by mixing the crude oil with water before bleaching,. The amount of water added for dsgmoeriog is preferably less than 15% by weight, wore preferably less than 10% by weight, fn one emteodlrneuh the afnbuht of water added is at least 0,2% by weight, while in a further embodiment is at least 0,5% hv wc«pht and in vet another embodiment is at least 1% by weight. The percentages Indicated are m sa\ <*e based on the etude oil used, Degumming, is canned out w about addition of acids

Degummtnc ts sattwO out at i ndutweh low temperature of less than 7tfiC, preferably less than htfiC, mote ptofetabh tn the mpu hon> % to 55%’, even snore preferably in the range from 40 to 50%.

The selected time for which the oil is treated for degammmg is preferably in the range from 10 to 30 minufes, particularly preferably fro?» 13 to 25 minutes;. After degymmmg, the lecithin phase is separated off from the degurnmed oil, for example by eenlrifugatton, decantation or by filtration, if the amount ol watet w less than 0 5% by weight, removal of the aqueous phase can he omitted, However, preference is given to the aqueous phase being separated otf from the degunnned oil esx·' m the k,tse o’ lehunci', sntrh a* wunx of w.n<·

The degurnmed oil is heated to a temperature in the range from 80 to IOO°C. preferably from 90 to !'?o\ , -"cr, pretembh .then* vs\ h ius osen mood thu ewessweb Inch tee.i'Ctahues e„u "?, bleaching lead to an increase in the concentration of 3-MCPD in the refined oil. Overheating of the oil should therefore be avoided. The bleaching earth is then added to the heated degurnmed oil. It has been found that when the amount of bleaching earth is too low, the concentration of 3-MCPO or 3-MCPO precursors which h.w< been formed during degumming cannot be reduced \,U'»twto b 1 Ik bieoc "g c nth o ?«. , ueUdcdeu n> e,c ' preferably in an amount in the range from 2,0 to 3,0% by weight, based on the crude oil, to tire heated degurnmed oil. The inventors assume that the bleaching earth has only a low adsorption posset for S-MtfeP and psceumom dieto-h p has been found that atmouph i-MCPD and precursors thereof are present. only in amounts in the ppm range in the oil, an increase io the amount of bleaching earth used for bleaching above an amount of 1.5% by weight leads to a stgnh < m l\ case m h .p> w n > Μ, Π' * p c Y xx ·. <

After addition of the bleaching earth to the heated oil, the oil is then bleached in a manner known per sc>

Bleaching, can be carried out by applying a vacuum immediately after addition of the bleaching earth, i.e. without having added water to the crude oh beforehand. Bleaching then occurs as pure vaetmm blenching. Ihc saenum bleaching is carried out at elevated temperature, particularly preiembly at temperntuwx of hem % m s Bi\' in one embodiment, bleaching is carried out in at least two stages, with wet bleaching firstly being canted out and vacuum bleaching being carried out subsequently.

For wet bleaching, the crude oil is firstly admixed with water. The amount of water selected is preferably in the range from 03)5 io 1.5% by weight particularly preferably front 0.1 to 1% by weight. The mixture is then stirred at from 80 to IGCTC, particularly preferably from 90 to 9S*C.

Vacuum bleaching is subsequently carried-out under the ePhdifidqs indicated above, i,e, preferably at temperatures of from SO to95sC and a pressure -in the regiotr of about 100 mbao.

After bleaching., the bleachiog earth w sepuatep oiT boot the bleached oil, Conventional methods can he used for this purpose·,· The bleaching earth can be allowed to sedmteni and the supernatant dear oh ean he decanted off. The bleached oil is usually filtered, lot example through a paper filter, xo v to eoo λ ,?! >>2 iv o>i ohm md < fie w vs, tt o’ On Hu,l'in«u t' *« u ' < " u^vheo oil is here referred to as filter oil regardless of the method used tot \cpnratmg oi l the bleaching earth. The filter oil is finally deodorized. Conventional methods under too usual M'Udifioos are employed for this purpose.

For this purpose* -superheated steam is passed through the. oil, giving, a ihil raffinate. The superheated steam preferably has an exit temperature in the range from 200 to 290sC, Deodorizatios is preferably carried out for a period of from 50 minutes to 2 hours, Oeodorization cun fee carried out in a single stage, with the exi t temperature of the superheated steam being kept substantially constant. However, if is siso possible to carry out fits cteodorteatson In a pin,mho oi stages, with the temperature of the superheated rteoru being altered during the decdorizafibn. Rote, preference is given to firstly introducing superheated steam having a temperature in the range from 250 to 29t.CC This first step is preferably carried out for a period of front 20 to <15 minutes. The exit temperature of the steam is subsequently reduced, preferably into a range from 200 to 240cC. The superheated steam is then preferably passed through the oil for &amp; further 50 to i 20 minutes. On hv t\}\ s o, otwe-x ,s h\ dr i«p too ' \ic Vf> u <c >, cu mums. dcodo'vnm n< m whs I -the inventors presume that h was previously bound in precursors, for example in glycerides or in compounds derived titereffosn,

The process of the invention makes h possible to achieve a low concentration of 3-MCPD in the refined oil when using essentially ail bleaching earths, i,e, both in the case of HPBE and also in the case of SM8£ and ΝΛΒΕ,

However, a further lowering of the concentration of J-MCPD in the refined oil can be achieved by careful selection of the bleaching earths used for bleaching.

Ptoference is given to using high-em face-area bleacbmg earths tor bleaching.

One embodiment provides for the bleaching earth a specific surface-area of more than 175 nf'/g, while in a further embodiment the specific surface arcs is mom than 220 nfi/g and to a further embudtment the specific vUtuho-' jua is mw than 300 mHg, In one etrtbodimenf,.the bleaching s >\ earth has a spec site sutlaee area oi h'xs than 400 m:/g.

Furthermore, the blenching earths used in the process of' the invention have, io a preferred entbodiment, a specific pore volume of mere than 0,2 trti/g, more preferably of more than 0.3 mi/g: particularly preferably a specific pore volume of snore than 0.4 ml/g. in one embodiment Ihe bleaching earth has a pore volume of mors than 0.45 ml/g and so a further embodiment a pore solume >»t less hem 0<5x o? y In one enthtahmom, « bleuehmg main wmen h ts a pots' volume m the range from 0,4 to 1,0 ml/g is selected, I he specific surface area (BET surface area) and the specific pore volume are determined by means of nitrogen porosunetry in accordance with DIN 66131 and evaluation by the 131H method. The total pore volume relates to pores basing a diameter of frosts 2 to 130 am.

The ion exchange capacity of the bleaching earths is preferably snore than i$ roeq/100 g, more preferably more than 23 meq./lOO g and tn one embodiment more than 40 meqflOO g. h is in principle possible to use all eonvsmf tonal bleaching earths in the process of the invention, h is thus possible to use both natural active bleaching earths (N'ABE) and acid-activated bleaching cart",r ns bhachtng eanhs ns nosd activated blenching earths a t> possible ό ts-m both surt'ace-activated bleaching earths tS.MBE) and highly active bleaching earths (HPflfi) obtained by extraction of a. raw c lay with strong acids.

However, it Ixo been fmtnd that the type of aetitathm of the bleaching earth used nt the process of the invention has art influence cm the amount of 3-MvPL· ptm.cn'. m the refined oil, .It hits surprisingly been found that acid-acttvated bleaching earths lead to lower concentrations of 3-MCPD in the refined oil. This is particularly surprising because, the addition of acid during degumming leads to an increase in the concentration of 3-.MCPD in the refuted oil, ;.c. the kummton of ΆΚ PD end precursors ot m.- compound ts mesumubb eunm w\l h\ m m

The acid-activated bleaching earth has, as a 10% strength slurry in water, a pH of preferably loss than '' end more preferably less than 4, In one embodiment, the pH of the finny is more than 2. Ip tn, e ' xx xm lx Its Πιη φΕ 1 stt > w I' m < «> he < mlxx m h w >. o ! of h s\ than -1 1 be pH is determined by means ofa pH elect» ode-

As aenhuwivakd hieacbmg cartlw, it n. pousihk brstfr t" use su?kt>.c-activated hteuHvag earths SXiltiA I'bcv .mrfacv octo xteo hie tcbtitg c utli.> »? vtnamed in mating -·. natonn saw Are ww. acid, with e\ec,w seal wmurenn.' on the chu, C!«w, !»>' wasomg step is canted cm man acts', atten

Before activation, tbs raw clay can be prepared in a corwentionai manner and, for cxareple, be dried or milled.

The surface activation of the raw <Ja\ can be carried oat by treating the raw clay with a preferably aqueous solution of the said «se<’ :of ac.isuoon.

The treatment can, for example, be carried out by moving, the raw day and spraying the soiution of the acid onto the raw clay, However, other methods are also possible for applying the solution of the acid to the raw clay, far example steeping,.

The nctn anon of the rac , ia> can, for example, be- carried out in the aqueous phase. For this: purpose, the acid is brought >«>· contact as aqueous so I utlon. with: the raw clay, Here, the raw clay, which is preferably provided in the form, of a powder, can firstly be slurried in water. The add is subseqttentiy added in conccmratcd form, Ho<ww :, the raw clay can also be slurried directly in an aqueous solution of the acid, or the aqueous »< noon of the acid can be added to the raw clay, in an advantageous embodiment, the aqueous acid solution can, for example, be sprayed onto a preferably crushed or pulverulent raw clay, with the arnounl of water preferably being selected to be very small and, lor example, a concentrated acid or acid solution being used: The amount of acid can preferably be selected in the range from I io 10% by weight, particularly preferably from 2 to 0% hv weight, of a strong acid, in particular a htincrai acid such as sulphuric acid, bused on the water- free raw clay (absolutely dry). If necessary, excess water can. be evaporated and the activated raw clay eau then be milled to the desired fineness. As already mentioned above, no washing step is required in this embodiment of the process of the invention, too. After addition of the aqueous solution of the acid, the clay is merely, if necessary,, dried until the desired moisture content has been reached, The water content of the bleaching earth product obtained is usually set to a |u >po,ts re ol k >s tire AfAb^vemh o >' ombb t w- ih m 1 S' J, w, gin

The activation can be carried out using either inorganic or organic acids. Suitable inorganic acids are, for example, sulphuric acid, phosphoric acid or hydrochloric acid, A suitable organic acid is, for example, citric acid.

The excess acid and the sails formed during activation are preferably not washed out. Rather, a washing step after addition of'the acid. as Is customary· io aesd acftvauon, is preferably not carried out; instead, the treated raw clay is dried and then milled to the desired particle size.

However, If Is also passible to activate the raw day dry and tot c\ unpb, ntftl site raw K ley together with a solid acid. A suitable acid is, for example, eirtie aetd Horom nulling the patUk ste,' n wt to the desired range.

The amount of acid used for activation is preferably selected to be greater than the too exchange capacity of the raw clay, preferably io the range front 100 Io 140% of the ion exchange capacity of the raw clay. A highly active bleaching earth (H'PBE) is preferably used as acid-activated bbaebmg earth. These highly active bleaching earths are obtained by extracting a raw clay with a strong acid at elevated temperature, preferably at about the boiling point. Here, alumiaium ions are basically leached from the crystal structure. Alter the extraction, the bleaching earth is separated off front the aqueous phase, for example by filtration, and then washed with water. This process is known per se to those shilled In the art. The highly activated bleaching earth Is likewise milled to the desired particle size.

The panicle size or the average particle size of the bleaching earth should pfe&amp;rably be selected so that complete end simple separation of the used bleaching earth from the refined product is possible. 'The average particle size of the pulverulent raw day is preferably selected in a range from 10 to 63 pm, The fineness is typloaliy selected so that from about 20 to 40% by weight of tbs mixture is -retained (as sieve residue) on a sieve having a mesh opening of 63 pm and 8w about 50 to 65%: by weight of the mixture Is retained on a sieve having a mesh opening of 25 pin, This can be designated as typical bleaching earth fineness.

The process of the invention is suitable in principle for the refining of any oils and fats. However, the: process of the invention is particularly suitable for refining vegetable oils.

Furthermore, the bleaching process of tbs invention is particularly suitable for iow-'pltosphorus oils which psetem'oP Mw a elbwphorus content of less than 100 ppm.

In particular, the process of the invention is preferably suitable for hleaebiog palm oil. fb. wmumw w 'Fortuned m mow Uokn below n uh ’bo ,ud of examples

Toe tedvwmg amUytiies-al methods were employed: s«£?.ifoS. volume:

The specific surface area was earned oat on a fully automated n'itfogen poroshneter them Mleromenucs. model ASAP ?Ott\ m aesmdame with DIN ooBl > Ihe pose volume wax dctetnnncd uvoi? tin ttfti nteihoh J 1' foureft i <j 3ewtct,ftV Hmcrnb, J, Am. Chen? See, 73 (! 951} 373), Pore volumes in particular pore size ranges are determined by adding up incremental pore volumes obtained from the evaluation of the adsorption isotherms by the BIB method The total pore volume obtained by the BJH method relates to pores having a diameter of horn 3 to I3 b nm. 1 he colour numbers in oils (tovlbood colour numbers} were determined its accordance with AOCS r\ t 'b~i$ The chlorophyll A determination was carried out in accordance with AOCS Cc i3d-55.

To determine the ion exchange capacity (llib'y the raw clay to be examined was dried at IO5''C tot a peru'U ,Troe hocr\ The dsnd mfoesnh was then mmree with an execs·' ef mj?e<>n.' 5\ \fU;Ci solution under reflux for one hour. After standing for 16 hours at room temperature, the mixture «b »>eu< „tn,w ·, r 'flu ,< < '-ο-, o whed <h MW'dini e 1 a < m M uukuo th O.V, via> was measured hr nitrogen denomination fCHN ar,ui\ss.r from I vcoi ucvoiding to the manufacturer's instructions. The proportion and type of the exchanged metal loss wore determined in the filtrate bv K.’fi spectroscopy. t-TTefsrdnaffoCub.ffiAf.flry

About 5b g of the air-dried mineral to be examined are weighed unto a sftwe having the desired mesh opening. The sieve is connected to a vacuum cleaner which sucks» ail tractions finer than the sieve through the sieve via a suction slit moving in a circular fashion coder the bottom of the sieve. The sieve Is covered with a plastic lid and the vacuum cleaner is switched on. After 5 rmnuigs, the vacuum cleaner is swashed off and the amount of coarser material remaining on the sieve is determined by difference weighing.

About 1 g of dned aampte is wmghed to wtthm 0 t tng in an touted, weighed porxdain erttcdrie with lid and ignited at 100(F!C for 2 hqnrs in r mu file iutttuce The crucible >a then quoted in a desiccator and weighed-

IfotefinufoAffoEbfohe.lfoMfoPO content

An aliquot of the oil to be examined is dissolved in t-BMbl/eihyl acetate and admixed with a deuterated standard solution and also an NaOClH? solution. The fatty acids are subsequently sopni.ued from the ,\qoe<'U» phase none iwaoc 1 he aqucoox | h w< w ,t,hnt\ed wuh nhcu' ibosonfc acid and dcrivalized at foT’C in a water bath for 20 nsinutes n (.ooihu the 3-MCPP derivative rs extracted with n-hexane and measured by means of GC-MS CEhte-, fdM nb dc). Chromaiogrnphy column: fused silica capillary coaled with methyl xilieone/phenyl stecnne, &amp;ΟΙ2Ϊ0 X - -unpin ot a conh mdu' oti n fasth leak'd e> the fenmmatmi tnd’CUKd to 1 tide 1 tot degnmmnnt sod then tit a-d and degassed at .100 mbar for 15 minutex After degassing, the palm oil was adnuved w«h the amount of 50% strength phosphoric actd or uatet indicated iu Table 1 and stirred at .nnluent p»assure for IS minutes.

The aqueous phase w,t\ thett xepmated otf where indicated (index ?T in Table I), the oil was brought to the tempeutme indicated nt 1 able I for hieachmg and the amount of bleaching earth huheated m fable 1 wax then added ibe ml was firstly bleached st aOnnsphuric pressure for 20 tninules and subsequently at a reduced pressure of 100 snbar for 50 minutes, The oil was filtered hoi through a paper inter. The filtered oil was liten deodorized by ttrxtiy passing superheated steam having an exit temperature of 271AC through the oil for 30 minutes and subsequently passing superheated steam having an exit tetnper,stare of TifteC through the oil for 60 minutes. Finally, the concentration of T-MCPfo was determined. The results are summarized in Table 1.

Table 1: Refining of palm oH

The hleaeihng earths ase<1 ih the eaempbs have the properties inchested ih Table 2:

Table 2: Ihyperrtes of bleaching earths

.As xaa be -.west sk-su Tabic L ,s tebttceh' Urge antount ot >»MCFO ot 550hppj« 1$ fortned so ?he case of a blank in which the palm oil is not degnmmed and bleaching Is carried out as a blank, i.e. without addition of bleaching earth. If degnmming Is additionally earned out, the amount of 3-MCPO increases to 61 SO ppm when water is added and a very high concentration of 3-.MCP0 of ,' h'>!> oom h>eod oboe phosptv so ,κη! n added if a bleaching earth is added during bleaching idler deguntming, significantly lower soncenirations of 3-.MCPD are measured so the full raffinate, The esc of bleaching earth thus does tsot unre ue the ·,< , ,n o c < hk ft) srs h<' uh s ft n t' out -, vk ' v<T > ( p ,, us < s >t t ' compound formed during refining of the oil.

If acid is added during dcgttnnning. higher values for .KM'CPD sn the full raffinate compared to -, -, s.snun..,.,......one w f w}, > , ---, \ , „ u \ - \k f \ >'i\ " decreasing ntrtount oi rend added during dogumming «at a constant concessit gloss of the ucsd> a«id also wsth decreasing actdlrt ol the sgucsmc \oinrtnn However, larger snnnnns rsf 3-Me.TU arc measured than so the case of degununing carried out only wtth addition of water. ff the temperature during degunttntng is also decreased and/or the amount of water added during -.1-, umun o » -, svstn, dis ,., , o, , ,-.' ' -, i\-u tun»'" ' ' Ή \)

Claims (5)

SZAB MMtMl IGFNYPOS FOK i. Procedure for Reducing 3'nnnClCl3, 1,2 ~ Diol in Fertilized Vegetable Oils, where n is the precursor gt anti-germination, smiU'l g anti-knit, we get the resin ntes oil down-oil. ohmtjuK akoi Vnnv.eft Daddy of our father, we've got scarred skin, and the scented oils are odorless, characterized by that,> vi mnnnnM, A a uJi tvi n. "t * m neo -, id t>>>>>>>>>>>> let me do a better job and do u mm uemum mm e k e emtusb) ^ μΙοληχόκ l« «ntk»> the erd'am for the resinous oil, the leaching agent is added at more than 5% by weight, - the bleaching is carried out at a temperature ranging from 80 to 5PC. fe 1 e npom> '<nn f ih <! "<' Ά d <'<.' \ t ! '- <mmn mnniedmh ,,; ï hí ï '> ïei hí ïeiei ïeiei ïeiei ïeiei ïeiei ïeiei ïei ï ï ïebb ïebb ïebb ïebb ïebb ï ï ï ï ï ï ï ï ï ï ï ï ï ï ï ï ï ï ï ï ï ï ï ï ï ï ï ï ï? The l. A process according to claim 1 or 2, wherein the solution of the resin is separated from the aqueous distillate. The method according to any one of the preceding claims, characterized in that the whitewash surface has more than .1? Srs7g of painful surface, Method according to one of the preceding claims, characterized in that the bleach is! pó-rnstérfo &amp; ata more than 0, z. ml / g. A method according to any one of the preceding claims, characterized in that the white-head is! ion exchange capacity of more than 15 meq / h g. Process according to the preceding claims, characterized in that the bleaching lip is acidic> Am d; Process according to claim 7, characterized in that the acid-activated curing agent is HbBE. he iwwptnnl bswíuk? and · .. see dkuuM? t> 'ob obm oil, H>. the / mmk djmos faces j <.lk-me /