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1. (WO2019027315) PROCESS FOR PRODUCING A REFINED PALM FRUIT OIL HAVING A REDUCED 3-MCPD CONTENT
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PROCESS FOR PRODUCING A REFINED PALM FRUIT OIL HAVING A

REDUCED 3-MCPD CONTENT

FIELD OF THE INVENTION

The present invention relates to a process for producing a refined palm fifth; oil having a reduced 3-MCPD content.

BACKGROUND OF THE INVENTION

Palm trees bear fruit in the thud year after planting and continue producing for about 25 years. Fruit bunches of 4 to 20 kg contain 200 to 2000 uxltvidual fruits and are harvested throughout the year. The fhnt bunches are transported to palm oil mills where crude palm oil is produced by mechanical and physical extraction processes along with palm kernels from which a further palm kernel oil can be produced. Typically, refined palm oil is produced from palm fruit by a multi-step process as described below.

Freshly cut fruit bunches are transported to the oil mill where they are sterilised to inactivate the lipolytic enzymes, loosen the fruit on the bunch, soften the fruit, condition the kernels, and cause pcotein to coagulate. The sterilisation process uses live steam at about 3 bar. Stripping the fri& from the sterilised

allow the fruits to pass through, but retain the empty bunches. The loosened fhnt is collected by a screw conveyor below the cage and the empty bunches emerge at the end of the cage. The separated fruit is then fed to a digester, whkh is a cylindrical, steam-jacketed vessel kept at 90 to 100°C by the unection of live steam and the addition of hot water, ft is fitted with beater arms that break up the fruit and liberate the oil. The digester contents are then fed contmuousry to a screw press that produces a liquid abeam consisting of oil, fines and aqueous phase, and a press cake containing the fruit fibre residue and the pahn kernels. The liquid stream is passed to a settling tank via a vibrating screen that returns what it retains to the digester. The oil recuperated from the settling tank is first of all passed through a clarifier and men dried (crude palm oil). The sludge collecting in the settling tank is passed to a decanter mat separates this sludge into a heavy effluent phase and a light, oily phase that is returned to the seating tank. The press cake emerging from die screw press is first of all broken up to separate the fibres from die nuts, then dried, and finally separated pacunuttically.

Crude palm oil undergoes several refining steps to produce refined palm oil. Depending on whether the refined palm oil is produced by chemical (aftaline) refining or by physical refining, these refining steps include deguinming, neutralization, bleaching and deoforisation above 200*C (chemical refining) or degununing, bleaching and deodefisation at 240-260°C (physical refining).


esters have been found in all refined vegetable oils such as margarine and oils, and in fat-containg foods inchidtng infant formula. The 3- MCPD esters are formed at high temperatures during the refining of edible fats and oils, mainly during the deodorisation step. The main factors for the formation of 3-MCPD esters are the presence of chloride ions, glycerol, tri- di- or monoacylgryceridea, as well as temperature and time (1LSI Europe Report Series, 2009).

Otaropropanols and their fatty acid esters (also known as chloroesters), are contaminants formed during the processing and manufacture of certain foods and ingredients. The fotmatkm of chloroesters may be widespread m processed foods derived from cereals, octree, fish, meat, potatoes, nuts and refined oils. CMoroesfeers may occur in many mgredknts that are processed by beat and the subsequent release of the chemical 3-MCPD from these materials during processing arid storage needs to

of 3-MCPD from mom anddi-esters of its fatty adds. Food Standards Agency).

Studies have identified 3-MCPD fatty acid esters in refined oils, such as refined palm oil whereby 3-MCPD fatty acid esters are believed to be formed at high ternperatures in the presence of water folk>wing a reaction between fats and chloride ions. In the refimng of palm fruit oil and fractions of palm fruit oil, 3-MCPD fatty acid esters are believed to be formed predonummtly during (leodorisation (where the oil is heated up to more than 200*0, the last stage in refining wherein undesirable odorous and taste-bearing substances are removed. 3- MCPD esters are formed during deodorisation due to a thermal catalysed decomposition of OTganochlorine confounds naturally occurring in palm oil into reactive chlorinated oonmounds such as hydrogen chloride. These compounds can react with acylglyoerols to yield MCPD diesters and also release the free fatty acids from the intact triglyceride molecule (Deskffflata. et al.. 2012). Besides 3-MCPD fatty acid esters, 2-MCPD fatty acid esters and glycidyi fatty acid esters have also been identified in these refined palm fruit oils.

Since the first finding of 3-MCPD esters and related compounds in vegetable oils, different possUnlities to mmmriae the formation during refining have been suggested, but only little mfbnnatioa are amiable about precursors for me fbnnation, but it is not clear yet how they act and whether a certain threshold value is necessary (Effect of Different Precursors on the Formation of 3-MCPD Esters and Related Compounds, Federal Research Institute for Nutrition and Food, Germany).

Processing techmques that minimise fbnnation of the 3-MCPD fatty add esters before and during the rcfming of crude palm fruit oil products have been suggested in the prior art

EP 2716746 Al describee a method for producing crude palm oO from which free chlorine (which is a substance causing fbraatkM of 3nriOi»ocbJoropropane-l^-diol (3-MCPD) fatty acid esters) is removed before the refining process via washing with water such ukia-pure water, distilled water, and/br dekndzed water, which coiiUins no chlorine ions wmch enables the suppression of formation of 3-MCPD esters. This method produces crude palm oil with free chlorine comem of 2 ppm

fatty acid esters of 1 mg/kg or less. This current method does not provide a combined solution from oil palm processing to palm oil refining to produce a refined crude palm oil with low levels of 3-MCPD esters.

EP 2471897 Al describes a method for reducing duotoffttmanoJs and a fbnutive substance in bleached and deodorized palm oil with silica gel and rcducrag a grycidol fatty acid ester via ascorbic acid (organic acid) whkh produces content of caforopropanols and a formative substance in the refined palm oil of 4 ppm or less. This current method does not provide a combined solution from oil palm processing to palm oil refining to produce a refined crude palm oil with low levels of 3-MCPD eaters.

WO 2011009843 Al describes the process of purifyiiig palm oil / palm stearm

an inert gas (i.e. nitrogen) and a deodorizatton step for removing off-taste and off-odours to limit the formation of MCPD in the oil A food product ooniprismg of this deodorized oil should contain less than 950 ug of bound.3-MCPD per kg of extracted faL This current

process does not provide a combined solution from oil palm processing to palm oil refining to produce a refined crude palm oil with low levels of 3-MCPD esters.

WO20I2169718A1. describes a method of removing chlorine ions from tap water used in the refining process after the degumming, deoxidizing, bleaching and deodorizing processes, lire edible oil. manufactured will have a content of 3-MCPD of 0.3 ppm or less. This current method does not provide a combined solution from edible oil processing to refining to produce a refined edible oil with low levels of 3-MCPD esters.

EP 2502500 Al describes a process to produce refined plant oil free of chlorinated contaminants from crude plant oil with use of liquid-liquid extraction with a polar solvent solution and a pre -treatment step of washing crude oil with acid. This process produces refined plant oil with MCPD content less than 1 ppm or preferably less than 0.3 ppm. This current process does not provide a combined solution from oil palm processing to palrn oil refining to produce a refined crude palrn oil with low levels of 3-MCPD esters.

WO 2015/174820 Al relates to a process of refined palm fruit oil products that yields a refined oil product having an exceptional low content of 3 -MCPD fatty acid esters. The process of refining a crude palm fruit oil products comprised of (a) removing phospholipids and'Or free fatty acids from a crude palm fruit oil product (b) simultaneously or sequentially contacting the pre-treated palrn fruit oil product with, a bleaching earth and a porous silica materia! to produce a bleached palm fruit oil product, and (c) deodorizing the bleached palm fruit oil product to produce a refined palm fruit oil product at a temperature of not more than 240°C. This current method does not provide a combined solution from oil palm processing to palm oil refining to produce a refined crude palm oil with low levels of 3-MCPD esters.

WO 2014/081279 Al relates to a process of refining palm oil in order to produce low level of 3-MCPD fatty esters in refined palm oil. Accordingly, the process comprises the steps of water degumming of crude palm oil, removal of aqueous phase by eentrifugation, followed by acid degumming at Sower temperature. Subsequently, bleaching is conducted with an activated bleaching earth and silicate adsorbent (for example magnesium silicate, calcium silicate and aluminum, silicate) as filter aid and final adsorption of the 3-MCPD fatty esters precursors prior to deodorization step. This current process does not provide a combined

solution front oil palm processing to ptfan oil refining to produce a refined crude palm oil with low levels of 3-MCPD eaten.

WO 2012/165397 Al describes a method for pioducing erode palm oil from which free chlorine has been removed from squeezed oil after squeezing in an o&sq\ieezing step and/or crude palm oil before pwikation in a purification step. The invention further provides for a crude palm oil in which a free cbior^

oil in which a content of 3-MCPD fatty acid esters is 1 mg/kg or leas by nramng the crude palm oil. This current method docs not provide a combined solution from oil palm processing to palm oil refming to produce arc

There remains a need in the art to provide a combined method to remove the 3-MCPD pcecursors in the crude palm fruit oU stage to prevent formation of 3-MCPD esters doting the refining stage, or to at least provide an alternative.

SUMMARY OF THE ΙΝνΈΝΤΙΟΝ

The present invention provides a process for producing a refined palm fruit oil having a reduced 3-MCPD content, the process including the steps of:

a. washing oflpahn fresh fruh bunches

to produce washed oU palm FFB;

b. subjecting the washed oil pahn FFB to sterilization, threshing, digestion and pressing to piodnce a cnide palm fruit o^

c. degumming of the erode pahn fruit oil to produce a degummed pahn fhrit oil;

d. h-ffachmg of the degummed palm fruit oil with a Weaching adsorbent to produce a bleached pahn fruit o3; and

e. deodorising the bleached pahn fruit oil at a temperature of not more than 24S0°C to produce a refined palm fruit oiL

Although the inventors do not wish to be bound by theory, it is believed that by washing the FFB before sterilisation, one or more 3-MCPD precursors are removed. These precursors (e.g. a chlorine source) are believed to be cuotsjned in contaminants (eg. soil, trash, dirt, insects) that are carried on the surface of the FFB. By removing these contaminants prior to oil

extraction, the present process enables the production of refined pahn fruK oil with reduced content of 3-MCPD esters.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a process flow diagram showing the general steps involved according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Retelling to Fig. 1, the present invention relates to a process for producing a refined palm fiuit oil having a reduced 3-MCPD content, die process mciuding die steps o£

a. washing oil palm fresh fruit bunches (FFB) with water havmg a temperature of 0 to 100°C to produce washed oil palm FFB;

b. subjecting the washed oil palm FFB to sterihzatkm, threshing, digestion and pressing to produce a erode palm fruit oil;

c. degimiming of the crude palm fhiit oil to produce a degummed pahn fruit oil;

d. bkadiing of the oVgirnirnrd pahn fruit oil with a bleaching adsorbent to produce a bleached pahn fruit oil; and

e. deodorising the bleached pahn fiuit oil at a temperature of not more than 260°C to produce a refined pahn fruit oil.

The term "water" as used herein in relation to the washing step, unless indicated otherwise, refers to an aqueous liquid such as tap water, surface water, ground water, spring water or treated waste water.

The term "oil" whenever used herein encompasses oils that are liquid, semi-solid or solid at 20°C. Typically, the crude palm fruit oil used in the present process contains at least 80 wt% triglycerides, more preferably at least 90 wt% of triglycerides. Examples of crude pahn fruit oilsthalmay bcrefmedby thepro

crude palm kernel oil, crude palm kernel oil fraction or combinations thereof. Preferably, the crude pahn fruit oil is crude palm oil or crude palm oil fraction.

The tola! chlorine content of Ihe erode palm fruit oil can be suitably determined by Mitsubishi NSX-2100 H, Trace FWnrntal Analyzer in accordance to standard ASTM D4929. The trace ekmental analyzer is a furnace system with a mkxo-coufometric detector that was used for tneasuiiag and detectmg totaled

A suitable analytical method for determining 3-MCPD fatty esters content of oils is described in AOCS Official Method Cd 29*-13. Glycidyi eaten are converted to 3-monobnmrapropanediol (3-MBPD) monoesters in an add solution containing a bromide salt. 3-MBPD esters, together with 2- and 3-MCPD fatty esters, are then converted into the free (noorceterified) form in acid methanolk solution. The fatty acid methyl esters generated during the reaction are extracted from the sample; 3-MCPD and 3-MBPD, derivatized with phenylboronic acid prior to GC-MS analysis.

OQ palm fresh fruit bunches (FFB) selected for the purposes of this invention typically have a five fatty acids (CTA) levd of

In the present process oil palm FFB are washed with water to remove 3-MCPD precursor. Besides the oil palm FFB, loose oil palm fhritkts may also be subjected to this washing

Heated conditions are preferred for the washing of the FFBe (and loose oS pahn fhritkts) as heated coalitions will assist to wash and/or dilate the wax layer protecting the surface of the FFBs and loose oil palm fruttkta. Accordingly, the water employed to wash the FFB preferably has a temperature in the range of 30 to 90°C, more preferably in the range of 40 to 80^ and nxist preferably m the r^

Accoiouig to a parttoilar^

wash the FFB is biologically treated discharge water, more preferably bk>logicaily treated £schaige water thai was discharged

The biologically treated discharge water employed in the washing step preferably has a total alkalinhy of 1,000-10,000 mg calcium carbonate (CaCO*) per litre, preferably 500 to 5,500 mg CaCQs per litre, more preferably 750 to 4,500 mg CaCOj per litre and even more preferably 1,000 to 3,500 mg ClaCOj per litre.

The period for washing the FFB preferably is in tbe timeframe of between 1 to 30 minutes, note preferably between 2.5 to 20 inmates, even more pisfimMyte

The washing of me FFB in the present process can be done in different ways. For instance, the FFB can be washed by spraying them with water. Alternatively, the FFB can be washed by submerging mem in a water bath.

As explained herein before, the washing step employed in the present process is believed to remove contaminants from the surface of the FFB, which contaminant* contain 3-MCFD precursors. In this context, examples of containments include soil, trash, dirt and insects. Preferably, the coiuaminitirts removed in the washing step are a source of chlorine.

The crude palm fruit oil obtained in the present process typically has a total chlorine content of 0 tp 10 ppm. More preferably, the crude pahn fruit oil contains 0 to S ppm total cbJorine, even more preferably 0.25 to 3.5 ppm total chlorine, and most preferably 0.5 to 2 ppm total chlorine.

The crude pahn fruit oil obtained in the present process typically contains 0.5 to 1.5% of FFA.

m this present process, the <kgnrnrnmg step is preferably conducted at a temperature range of between 6O°C to 120°Ct preferably 70°C to 115ºC even more preferably 80ºC to110ºC for a time period of between 1 to 30 imrartes, preferably 5 to 25 minutes, even more preferably for 10 to 20 minutes using organic acid or mineral acid or any combination thereof Longer drgumming time period man what is proposed have been tested and deem not ccmnierciaUy feasible as h will affect the efficiency aitd throughput of uie palm m

Regardless of any drgimmmg agent used, the acid dosage according to mis invention is between 0.01 to 0.12%, preferably 0.02 to 0.1%, even more preferably 0.03 to 0.08% for the removal of gums. The range of acids usually depends on the amount of gums (i.e. phospholipids / phosphatides) which are present in the crude palm oil. Common industrial practice of acid dosage is in the range of 0.04 to 0.08% with normal usage around 0.06%.

In accordance to this present invention, the degumming agent used is phosphoric acid with 80 to 95% concentration or citric acid with 30 to 50% concentration or any combination thereof. However, preferably the degumming agent used for this invention is citric acid with 30 to 50% concentration for the removal of the gums.

In the bleaching step of this present invention, a bleaching adsorbent is used in order to further remove any remaining contaminants, such as colour pigments, metal ions, oxidation products and chlorinated compounds to produce a bleached palm fruit oil.

The bleaching adsorbent used in this present invention is preferably selected from bentoniie clay, palygorskite clay, monimorUionite clay, smectite clay or any combination thereof. Preferably, the bleaching adsorbent is In the form of naturally active clay, acid activated bleaching clay, thermal activated bleaching clay or any combination thereof. However, more preferably the bleaching adsorbent is in the form of thermal activated bleaching clay.

In accordance to this present invention, the amount of bleaching, adsorbent used is between 0.5% to 3%, preferably between 0.75% to 2.5%, even more preferably between 1 % to 2%, by weight of the degummed palm fruit oil. Normal practice by oil palm refineries uses the bleaching adsorbent dosage of between 0.08 to 1.2% depending on the quality of the crude palm oil 2% is the highest dosage allowable because of the plant limitation at the refineries.

in accordance to this present invention, the degummed palm fruit oil is contacted with the bleaching adsorbent at temperatures between 85°C to 130°C, preferably between 90c€ to I25°C, even more preferably between 95°C to 120°C for 10 minutes to 90 minutes, preferably for 15 minutes to 75 minutes and even more preferably for 20 minutes to 60 minutes.

In this present invention, the bleached palm fruit oil has a total chlorine content of between 0 ppm to 3 ppm, more preferably between 0.15 ppm to 2.5 ppm, even more preferably between 0.3 ppm to 2.0 ppm, prior to the deodorisaiion step.

In this present invention, deodorisation of the bleached palm fruit oil is preferably carried out at the temperature of 2O0-25O°€ to produce a refined palm fruit oil. Preferably, the bleached palm fruit oil is deodorised for 20-180 minutes, more preferably for 30-150 minutes.

Typically, the deodorisation according to the invention is earned out at a pressure of 5 mbar and below.

The standard current practice at the refineries uses phosphoric acid drpimtning approach together with acid activated bleaching clay. This present invention explores a combined effort from washing of FFBs at the milk prior to processing and at the refinery stage, uses phosphoric acid or citric acid for the (tegununing step and various bleaching adsorbent to produce the refined palm fruit oil with the lowest 3-MCPD content possible. This combined approach has not been described in known prior arts in this field of interest

Advantageously, the present mvention using the said combined approach produces a refined palm fruit oil with 3-MCPD content of between 0 to 1.5 ppm 3-MCPD esters, peferabry 0 to 1 ppm 3-MCPD esters, more preferably 0 to 0.S ppm.

The invention is further Uhetrated by the following ixm-lunitrag examples.

EXAMPLES

CPO from unwashed FFBs

Crude palm oil (CPO) with free fatty acids of 4%, peroxide value (PV) of 4.47 meq C¾fcg. detericntkmofbleechabilfy (DOBI) of 2.7 and total cbiorine content of S.0 ppm was dkegimimed, bleached and deodorised as per details in Table 1.

CPO from washed FFBs

Fresh fruh bunches (FFBs) were selected baaed on their ripeness quality, indicated by the free fatty acid (FFA) content containing FFA of more than 3%. The FFBs were subjected to washing using biologically treated discharge water trader heated condition of 60°C and washing time of 4 minutes. The biologically treated discharge water used as a washing agent had a total alkalinity of 1204 mg.CaCOyL Then the FFBs were sterilised using the mill's steriliser cage and extracted for its oil manually. The content of the erode palm oil of the washed FFBs were then tested and found to contain 0.89% FFA, 0 <¼ meq/kg.3.1 S DOBI and 0.77 ppm total chlorine.

Fanrrlf ?

CPO from washed FFBs - Phfwnhoric Acid DcOTimming (Acid Oav vs Thermal QtsiL BJeacMBg)

The crude pahn oil obtained from the washed FFB of Example 2 were then subjected to the rcfhiirig process usir^

Table 2



Exemple 4

CPO from washed FFBs - Chric Acid Dewimming (Add Chv vs Thermal CUv Bleaching) The crude palm oil obtained from me washed FFB of Example 2 were then subjected to citric ac^degummiiig, acid clay and

Tabk 3


Summary Results