1.Palm Oil Refining

Tek. Peng. Nabati 2 - Teti Estiasih - THP

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Pemurnian (purification   ) bertujuan untuk menghilangkan senyawa ikutan yang sering disebut sebagai impurities (kotoran) dalam minyak Perubahan minyak kasar (crude oil   ) menjadi minyak makan (edible oil   ) Meliputi satu atau lebih proses berikut:  , netralisasi atau atau physical refining, refining, degumming   , dan deodorisasi deodorisasi bleaching  Tek. Peng. Nabati 2 - Teti Estiasih - THP

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Pemurnian (purification   ) bertujuan untuk menghilangkan senyawa ikutan yang sering disebut sebagai impurities (kotoran) dalam minyak Perubahan minyak kasar (crude oil   ) menjadi minyak makan (edible oil   ) Meliputi satu atau lebih proses berikut:  , netralisasi atau atau physical refining, refining, degumming   , dan deodorisasi deodorisasi bleaching  Tek. Peng. Nabati 2 - Teti Estiasih - THP

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Proses ekstraksi minyak menyebabkan sejumlah senyawa non trigliserida terbawa Meliputi: asam lemak, gliserida, fosfatida, sterol, tokoferol, hidrokarbon, pigmen (klorofil, karoten), fragmen protein. Jenis minyak yang berbeda: kotoran berbeda Contoh: minyak hewani, CPO dan PKO : asam lemak bebas; minyak canola: klorofil Kotoran tertentu dikehendaki seperti sterol dan tokoferol Tek. Peng. Nabati 2 - Teti Estiasih - THP

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Menghilangkan senyawa yang tidak dikehendaki tertentu dengan meminimalkan kerusakan trigliserida kotoran yang dihilangkan: asam lemak bebas, fosfatida, gum, dll Proses pemurnian meliputi: bleaching (penghilangan warna), deodorisasi (penghilangan bau), refining (penghilangan asam lemak bebas), degumming (penghilanganTek.gum) Peng. Nabati 2 - Teti Estiasih - THP

Proses pemurnian PROSES

PROSEDUR

KOTORAN YANG DIHILANGKAN

H3PO4 , H20, 7080 C

fosfolipid, trace metal, pigmen, karbohidrat, protein

Netralisasi

NaOH (alkali lain)

Asam lemak, fosfolipid, pigmen, trace metal, senyawa bersulfur, oil-insoluble, water soluble

Pencucian

H2O

Sabun

Drying 

Na2SO4 anhidrat Air

Bleaching 

Bentonit, adsorben lain

Degumming 

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Filtrasi Deodorisasi atau Physical refining

Pigmen, produk hasil oksidasi, trace metal, senyawa bersulfur, trace of soap Spent of bleaching earth

Steam under Asam lemak, MG dan DG, produk reduced pressure oksidasi, produk dekomposisi pigmen, Tek. Peng. Nabati 2 pestisida, - Teti Estiasih - trace THP of oil-insoluble

Proses pemurnian secara kimiawi (kiri) dan fisik (kanan)

Storage of crude oil

Degumming Netralisasi Washing Drying Bleaching Filtration

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Bleaching Filtration

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Storage of  partly refined oil

Deodorization Polishing Cooling

Steam refining Polishing Cooling

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Storage of  Tek. Peng. Nabati 2 - Teti Estiasih refined oil - THP

By Product

PROSES

BY-PRODUCT

Degumming

Lesitin

Netralisasi

Asam lemak

Pencucian Steam refining

Asam lemak, mono dan digliserida Tek. Peng. Nabati 2 - Teti Estiasih - THP

DEGUMMING •

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Pada proses ini minyak dipanaskan dengan penambahan asam fosfat Perlakuan ini dilakukan jika sebagian besar senyawa berfosfor dapat terhidrasi dan menggumpal/tidak larut By product dari proses ini adalah lesitin

Tek. Peng. Nabati 2 - Teti Estiasih - THP

NETRALISASI •

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Netralisasi merupakan perlakuan dengan alkali yang dilakukan pada kondisi tertentu sehingga kehilangan minyak netral (trigliserida) serendah mungkin Pemurnian fisik (physical refining atau steam refining) merupakan alternatif lain untuk menghilangkan asam lemak bebas

Tek. Peng. Nabati 2 - Teti Estiasih - THP

BLEACHING • •

Terutama ditujukan untuk menjernihkan Dilakukan dengan pemanasan minyak (80180 C) tetapi biasanya dilakukan antara 90-120 C. Pada kondisi tanpa oksigen dengan menggunakan adsorben Adsorben dapat berupa bentonit, fuller’s earth, karbon aktif, silika amorf  Tingkat penggunaan adsorben adalah 0.2-2.0% dari berat minyak Minyak sawit dapat dibleaching dengan pemanasan suhu tinggi tanpa menggunakan Tek. Peng. Nabati 2 - Teti Estiasih - THP adsorben 

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DEODORISASI ATAU PEMURNIAN FISIK •

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Merupakan langkah terakhir proses pemurnian yang bertujuan mendapatkan minyak yang tidak berbau dan daya simpan tinggi Proses ini terutama bertujuan menghilangkan produk hasil oksidasi yang berperan terhadap bau minyak Dilakukan dengan pemanasan suhu tinggi (170250 C) pada tekanan rendah dengan menggunakan uap air Penggunaan suhu yang tinggi (lebih dari 220 C beresiko terhadap streomutasi yang biasa terjadi pada asam linolenat Tek. Peng. Nabati 2 - Teti Estiasih - THP 

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PEMURNIAN MINYAK SAWIT

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Tek. Peng. Nabati 2 - Teti Estiasih - THP

Tek. Peng. Nabati 2 - Teti Estiasih - THP

EKSTRAKSI MINYAK SAWIT KASAR (CPO, CRUDE PALM OIL) •

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Beberapa tahapan ekstraksi minyak dari tandan sawit adalah: Sterilisasi

2. Pelepasan buah (bunch stripping   ) 3. Digesti 4. Ekstraksi minyak 5. Klarifikasi dan Purifikasi Tek. Peng. Nabati 2 - Teti Estiasih - THP

Klarifikasi dan Purifikasi •

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CPO yang diekstrak mengandung air, padatan, dan partikel-pertikel terlarut yang harus dihilangkan Partikel serat dipisahkan dari CPO dengan melewatkan minyak pada penyaring bervibrasi. Pasir dan kotoran dipisahkan dengan cara pengendapan Air dipisahkan dengan cara pengendapan atau sentrifugasi dilanjutkan dengan pengeringan vakum Tek. Peng. Nabati 2 - Teti Estiasih - THP

Crude Palm Oil

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PEMURNIAN dan FRAKSINASI

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Komponen Minor •

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Komponen minor dalam CPO adalah fosfolipid, karbohidrat, trace metal, ALB, mono- dan digliserida, sterol, pigmen karotenoid, tokoferol, tokotrienol, produk hasil oksidasi, dan komponen-komponen berbau Pemurnian mengurangi komponen pengotor yang dapat mempengaruhi mutu minyak akhir dengan tetap mempertahankan tokoferol dan tokotrienol Proses pengolahan setelah ekstraksi adalah pemurnian danTek.fraksinasi Peng. Nabati 2 - Teti Estiasih - THP

Refining Crude Palm Oil: Unit Processes

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Refining Bleaching Deodorizing of Palm Oil

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Neutralizing, Bleaching, Deodorizing of Palm Oil

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A. PHYSICAL REFINING •

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Dilakukan dengan steam distillation pada suhu tinggi dan kondisi vakum Terdiri dari dua tahap utama, yaitu pretreatment dan distilasi

Tek. Peng. Nabati 2 - Teti Estiasih - THP

1. Pretreatment •

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Dilakukan dengan proses degumming menggunakan asam fosfat dilanjutkan dengan bleaching Bleaching dilakukan dengan proses adsorpsi pada kondisi vakum, suhu 90-130C, dilanjutkan dengan filtrasi Pretreatment mengurangi kadar fosfolipid, trace metal, peroksida, dan karotenoid. Tek. Peng. Nabati 2 - Teti Estiasih - THP

2. Degumming •

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Pretreatment refers to the initial degumming of  crude palm oil with concentrated phosphoric acid and the subsequent adsorptive cleansing with bleaching clay. Crude palm oil is dosed with phosphoric acid (80 – 85% concentration) at a rate of 0.05–0.2% (of the feed oil), heated to 90–110C, and given a residence time of 15–30 min before passing to the bleacher where bleaching earth is added as a slurry. The earth required ranges from 0.8 to 2.0%, depending on the quality of the crude oil. Tek. Peng. Nabati 2 - Teti Estiasih - THP

The purpose of the phosphoric acid is to precipitate the nonhydratable phosphatides while the function of the earth is fourfold: •

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to adsorb the undesirable impurities such as trace metals, moisture, insolubles, and part of  the carotenoids and other pigments to reduce the oxidation products to adsorb the phospholipids precipitated by the phosphoric acid to remove any excess phosphoric acid present in the oil after degumming. Tek. Peng. Nabati 2 - Teti Estiasih - THP

Removal of Phosphoric Acid •

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Complete removal of residual phosphoric acid in the bleaching stage is also critical as any ‘‘slip through’’ can result in the rapid rise of  free fatty acid content and color of the final RBD oil As a further assurance, a suitable quantity of  calcium carbonate is often added after dosing of the bleaching earth to the degummed oil, to help neutralize the residual phosphoric Tek. Peng. Nabati 2 - Teti Estiasih - THP acid

3. Bleaching •

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Bleaching is carried out under a vacuum of 20 –25 mmHg and at a temperature of 95–110C with retention time of 30–45 min The slurry containing the oil and earth is then filtered to recover a clear, light orange color pretreated oil Usually a small amount of diatomaceous earth is used to precoat the filter leaves to improve the filtration process. As a quality precaution, the filtered oil is polished through another security filter bag in series, to trap any earth particles that the first filter Tek.escape Peng. Nabati 2 through - Teti Estiasih - THP

Loss of Oil •

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This is essential as the presence of spent earth particles in the pretreated oil reduces the oxidative stability of the final RBD oil The spent bleaching earth from the filter normally contains about 20–40% oil, and this is the major source of oil loss in the refining process Tek. Peng. Nabati 2 - Teti Estiasih - THP

4. Deodorization •

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The pretreated oil is then ready for deacidification and deodorization. The pretreated oil is first deaerated followed by heating to 240–270C in an external heat exchanger before pumping into the deodorizer, which is kept under a vacuum of  2–5 mm Hg Superheated high-pressure steam is now commonly being used, Tek. Peng. Nabati 2 - Teti Estiasih - THP

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Temperatures above 270C are to be avoided to minimize loss of neutral oil, tocopherols/tocotrienols, and also the possibilities of isomerization and undesirable thermochemical reactions Under such conditions and with the help of stripping steam, the free fatty acids, which were still present in the pretreated oil, are distilled together with the more volatile odoriferous and oxidation products such as aldehydes and ketones, which otherwise would impart undesirable odor and taste to the oil At the same time, the residual carotenoids present are also thermally decomposed, and the end result is the production of a light-colored, bland RBD palm oil Tek. Peng. Nabati 2 - Teti Estiasih - THP

Cooling after Deodorization •

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To maximize the recovery of thermal energy, the hot deodorized oil is heat exchanged against incoming pretreated oil to be cooled down to a temperature of 120–150C Further cooling is effected by water down to 55–65C prior to storage Antioxidant and citric acid, if required, are dosed into the RBD palm oil at this stage Tek. Peng. Nabati 2 - Teti Estiasih - THP

DALMS/PFAD

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Desirable Quality of Pretreated and RBD Palm Oil from the Factory

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B. CHEMICAL REFINING •

Also called caustic refining, chemical refining involves three stages:

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(1) gum conditioning and neutralization

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(2) bleaching and filtration

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(3) deodorization.

Tek. Peng. Nabati 2 - Teti Estiasih - THP

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Alkali refining sesuai untuk minyak dengan kadar ALB tinggi Kelemahan alkali refining : terjadi penyabunan minyak netral menyebabkan refining loss Steam refining : hanya menghilangkan ALB sehingga refining loss rendah Syarat minyak untuk steam refining : kadar fosfatida rendah dan tidak sensitif panas Sebelum refining : fosfatida harus dihilangkan Tek. Peng. Nabati 2 - Teti Estiasih - THP

1. Gum Conditioning and Neutralization •

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The crude oil is heated to a temperature of  80–90C. Phosphoric acid of 80–85% concentration is then dosed in at a rate of  0.05–0.2% (of the feed oil) This serves to precipitate the phospholipids After this, the degummed oil is further treated with a caustic soda solution

Tek. Peng. Nabati 2 - Teti Estiasih - THP

Neutralization •

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A caustic soda solution of about 4 N (or 20 Be´) concentration with a calculated excess (based on free fatty acid content of the crude oil) of about 20% The reaction between caustic soda and the free fatty acids in the degummed oil results in the formation of sodium soap, which is readily removed by a centrifugal separator The lighter phase discharged consists mainly of neutralized oil containing 500–1000 mg/kg of soap and moisture while the heavy phase is mainly soap, insoluble impurities, gums, phosphatides, excess alkali, and a small quantity of oil loss through emulsification As an excess of alkali is used, it is unavoidable that a slight loss of neutral oil through saponification also occurs Tek. Peng. Nabati 2 - Teti Estiasih - THP

Washing •

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The neutralized palm oil (NPO) is then washed with 10–20% hot water to remove traces of soap still present After another stage of centrifugal separation, the washed oil is then dried under vacuum to a moisture level below 0.05%.

Tek. Peng. Nabati 2 - Teti Estiasih - THP

2. Bleaching and Filtration •

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The neutralized palm oil is treated with bleaching earth in a similar manner as that described in physical refining In this case, the earth also removes traces of  soap that are present

Tek. Peng. Nabati 2 - Teti Estiasih - THP

3. Deodorization •

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The neutralized and bleached oil is then channeled to the deodorizer in a similar manner to that in the physical refinery The oil is subjected to distillation at a temperature of 240 – 260C and a vacuum of 2–5 mm Hg with direct steam injection Under such conditions, residual free fatty acids, volatile oxidation products, and odoriferous materials are removed together with thermal decomposition of carotenoids The final product, called neutralized, bleached, and deodorized (NBD) palm oil is then cooled down to 60C and passed through polishing filter bags before pumping to the Tek. Peng. Nabati 2 - Teti Estiasih - THP storage tanks

Refining Factor •

The efficiency of the refining process is estimated by the use of a refining factor (RF)

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Desirable Quality of Freshly Produced Intermediate and Final Products in Alkaline Refining of Palm Oil

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FRAKSINASI •

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Trigliserida utama dalam minyak sawit adalah oleodipalmitin dengan titik leleh 37C dan palmitodiolein dengan titik leleh 19C Tujuan fraksinasi adalah menghasilkan fraksi olein yang cair (slip melting point 21.6C dan cloud point 8.8C) dan fraksi padat stearin Fraksi olein digunakan terutama untuk minyak goreng dan minyak masak, sedangkan fraksi stearin digunakan untuk, margarin, shortening, dan minyak goreng Fraksinasi dilakukan dengan dua proses yaitu dry fractionation dan detergent fractionation Tek. Peng. Nabati 2 - Teti Estiasih - THP

Fractionation and PMF

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Fatty Acid Compositions (%)

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Melting and Solidification Characteristics

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Dry Fractionation •

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Minyak dipanaskan pada suhu 70-75C untuk melelehkan inti-inti kristal Minyak panas tersebut dimasukkan ke dalam crystallizer dan didinginkan pada suhu 18-20C selama 4-8 jam Proses ini menghasilkan minyak dalam bentuk sluri Fraksi padat dan cair dipisahkan dengan filtrasi membran Tek. Peng. Nabati 2 - Teti Estiasih - THP

Detergent Fractionation •

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Pada proses ini pemisahkan fraksi padat dan cair dalam sluri dari crystallizer dilakukan dengan mencampur sluri dengan deterjen Deterjen yang digunakan natrium lauril sulfat atau magnesium sulfat Pada proses sentrifugasi fraksi olein yang lebih ringan terpisah dari fraksi akueous yang mengandung stearin Fraksi olein kemudian dicuci dan dikeringkan, sedangkan fraksi stearin direkoveri dari fraksi akueous dan deterjen didaur ulang Tek. Peng. Nabati 2 - Teti Estiasih - THP

Solvent Fractionation •

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This process is the most expensive because of solvent loss, solvent recovery equipment, much lower temperature requirement, and stringent safety features The process involves the use of solvents such as hexane or acetone The oil is first dissolved in the solvent followed by cooling to the desired temperatures to obtain the desired crystals The miscella containing the partially crystallized oil and solvent is then filtered under vacuum suction in an enclosed drum filter The olein miscella and stearin miscella are then separately distilled to remove the solvent and recover the fractions Yield of olein is about 80% The solvent process nowadays is only viable in the production of  high value products such as cocoa butter equivalent or other Tek. Peng. Nabati 2 - Teti Estiasih - THP specialty fats

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Second Fractionation/ Double Fractionation •

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Dilakukan untuk mendapatkan superolein dengan titik leleh dan titik kabut rendah dan bilangan iodin tinggi Palm Mid Fraction (PMF) diperoleh sebagai fraksi stearin dari fraksinasi kedua ini PMF lebih lunak

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Jenis Asam Minyak Sawit dan Fraksinya Jenis Asam Lemak

Refined

RBD Olein (Double Fractionation)

RBD Stearin

PMF

Palm Oil

RBD Palm Olein

Laurat

0.2

0.2

0.1

0.3

0.1

Miristat

1.1

1.0

1.0

1.5

1.2

Palmitat

44.0

39.8

36.6

52.0

51.0

Palmitooleat

0.1

0.2

0

Stearat

4.5

4.4

4.0

4.9

5.6

Oleat

39.2

42.5

44.8

33.3

34.0

Linoleat

10.1

11.2

12.6

7.6

7.4

Lunolenat

0.4

0.4

0.2

0.1

0.1

Arakhidat

0.4

0.4

0.7

0.3

0.6

Jenuh

50.2

45.8

42.4

59.0

58.5

MUFA

39.2

42.5

44.8

33.3

34.0

PUFA

10.5

11.6Nabati 2 - Teti Estiasih12.8 Tek. Peng. - THP

7.7

7.5

Krakteristik Minyak Sawit dan Fraksinya RBD Olein (Double Fractionation)

RBD Stearin

PMF

Palm Oil

RBD Palm Olein

Bil. iodin

53.3

58.0

61.4

44

42.5

Slip melting point ( C)

36.0

21.6

19.0

44-56

5 C

62.2

51.1

10 C

50.3

37.0

16.7

61.2

76.1

15 C

35.2

19.2

5.0

53.1

66.2

20 C

23.2

5.9

3.1

43.4

52.1

25 C

13.7

33.9

21.9

30 C

8.5

27.0

18.3

35 C

5.8

22.2

13.4

Karakteristik

Refined

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Solid Fat Content (%) 

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67.2

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QUALITY ASSURANCE •

The two main quality problems associated with palm oil are hydrolysis, leading to formation of fatty acids, and oxidation, leading to rancidity

Tek. Peng. Nabati 2 - Teti Estiasih - THP

Hydrolysis •

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The hydrolysis of palm oil is promoted by the presence of free moisture and heat and also by lipolytic enzymes endogenous to the plant tissue This mode of deterioration occurs during the bruising of fruits in the harvesting and transportation of the FFB to the mill and also their extended storage under unfavorable conditions In the case of oil during storage, the hydrolysis is attributed to a chemical reaction that is autocatalytic ith poor cold stability Tek. Peng. Nabati 2 - Teti Estiasih - THP

Hydrolysis •

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The presence of high FFA in crude palm oil is undesirable: (1) reduces the yield of RBD palm oil through higher loss of  PFAD by-product (2) reduces the capacity of refining (3) results in poor bleachability of crude oil and poor stability in the final product Crude palm oil with high FFA content invariably also contains a high amount of partial glycerides, especially diglycerides Interactions between the diglycerides and the triglycerides often lead to formation of eutectics resulting in poor crystal formation during fractionation, difficulty in separation of olein and stearin by filtration, and also in production of olein with poor cold stability Tek. Peng. Nabati 2 - Teti Estiasih - THP

Oxidation •

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Oxidation of oils and fats is due to prolonged exposure to air Palm oil is relatively more stable to oxidative deterioration than the polyunsaturated vegetable oils In the presence of trace metals such as iron and copper, excessive oxidation at the olefin bonds of the oleic and linoleic acids can occur, resulting in rancidity Highly oxidized crude palm oil is known to have poor bleachability and thus requires more bleaching earth and more severe refining conditions, and the final product will likely be of poor stability Tek. Peng. Nabati 2 - Teti Estiasih - THP

Quality Assurance Measures in Plantation and Milling •

Availability of goodquality crude palm oil is a prerequisite for the production of good-quality refined palm oil products

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The criteria for good-quality crude palm oil are:

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Low free fatty acid content

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Low in oxidation characteristics

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Good bleachability

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Low in trace metals and insoluble impurities

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Moisture content of about 0.15 –0.20%

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High in deterioration of bleachability index (DOBI) Tek. Peng. Nabati 2 - Teti Estiasih - THP

DOBI = Deterioration of Bleachability Index •

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DOBI, which is defined as the ratio of the uncorrected absorbance absorbance values at 446 nm to that at 269 nm, was introduced as a quality parameter to differentiate the refinability of  good- and poor-quality crude palm oil The relation to quality is DOBI >3, good; 2.4– 2.9, fair, and