3.4_Deodorization.ppt

8/10/2019 3.4_Deodorization.ppt

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Processing of Edible Oil

(Palm Oil)

CHAPTER 3


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3.4 : Deodorization


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Introduction

CPB 30303 (JAN 2014)3

Deodorization is usually the last refining processcarried out to improve the taste, odor, color, and

stability of the edible oils.

In commercial deodorization steam strip-ping is

used to remove undesirable volatile compoundssuch as FFA, aldehydes, ke-tones, and alcohols.

However, a simultaneous loss of nutritionally

beneficial bioactive oil components occurs.


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Introduction

CPB 30303 (JAN 2014)4

Complex chemical and physical changes occur inoil composition during deodorization.

Thermal decomposition of oxidation products and

pigments, and hydrolysis of conjugated polyenoic

compounds and TG are some of the chemicalreactions that take place during steam stripping


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Objectives

CPB 30303 (JAN 2014)5

Although the process is commonly nameddeodorization, it is actually a combination of threedifferent effects on the oil:

(1) stripping: Stripping of volatile components(free fatty acids, odorous compounds,tocopherols, sterols, and contaminants such aspesticides and light polycyclic aromatichydrocarbons, etc.),

(2) deodorization: Removal of different off-

flavors, and (3) temperature effect.: Thermal destruction of

pigments and unwanted side reactions such ascis-trans-isomerization polymerization,

conjugation, and so on.


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Deodorization

CPB 30303 (JAN 2014)6

Odoriferous compounds are from: Aldehydes

Ketones

Others partially eliminated:

Volatile components such as FFA, alcohol,

sterols and tocopherol


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Deodorization

CPB 30303 (JAN 2014)7

During deodorization flavor compounds can beformed by hydrolysis and thermal decomposition

Peroxides are decomposed by heat

These reactions plays a major role in the flavor

stability improvement achieved by deodorization ofvegetable oils & fats


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Deodorization

CPB 30303 (JAN 2014)8

High deodorization temperature , air inside thevessel can initiate oxidation with severe

impairment of taste and flavor stability.

Residence time and steam volumes significantly

required compare to normal distillation.


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Deodorization

CPB 30303 (JAN 2014)9

Thermal decomposition with protiens,carbohydrates, phospatides and soap also can

cause flavor and taste stability

Deodorization is performed in vacuum because the

lower partial vapor pressure of the compounds tobe removed.


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Deodorization

CPB 30303 (JAN 2014)10

Consumption of stripping steam increases withdecreasing vapor pressure of the volatile

components and with the increasing pressure in

the deodorizer


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Deodorization

CPB 30303 (JAN 2014)11

Optimal stripping parameters (temperature, time,operating pressure, and amount of stripping gas)

are governed by the properties of the ingoing

product, the specifications of the outgoing product,

equipment limitations, and the need to minimizecosts.


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Deodorization

CPB 30303 (JAN 2014)12

Method of operation: Batch

Continuous

Semi continuous


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Deodorization

CPB 30303 (JAN 2014)13

Most edible oils and fats can be deodorized attemperatures ranging from 230260 C with

pressure of

approx. 23 mbar.


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Deodorization

CPB 30303 (JAN 2014)14

High quality of the deodorized oil due to: excellent efficiency in stripping of high free fatty

acid contents by utilizing a stripping columnduring continuous processing

extremely low contamination between differentfeedstock materials during product change insemi-continuous processing mode

dosing of citric acid to form complexes with theheavy metals in the oil in order to lower theoxidation rate of the deodorized oil

moderate increase of trans-isomers whendeodorizing at lower temperatures


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Stripping

CPB 30303 (JAN 2014)15

Vapor pressure The volatility of a given component is expressed

by its vapor pressure, which increases with

increasing temperature (Figure 2).

The lower the vapor pressure, the lower thevolatility and, thus, the more difficult to remove

the component from the oil. For each specific

component, the vapor pressure-temperature

relationship can be expressed by the Equation ofAntoine:


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Stripping

CPB 30303 (JAN 2014)16


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Stripping

CPB 30303 (JAN 2014)17


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Stripping

CPB 30303 (JAN 2014)18


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CPB 30303 (JAN 2014)19


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CPB 30303 (JAN 2014)20

Crude Bleached oil Bleached &Deodorized oil


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Deodorization.

CPB 30303 (JAN 2014)21


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Deodorization.

CPB 30303 (JAN 2014)22


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CPB 30303 (JAN 2014)23


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CPB 30303 (JAN 2014)24


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CPB 30303 (JAN 2014)25


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CPB 30303 (JAN 2014)26


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For example: Vapor pressure calculation of

compositions

CPB 30303 (JAN 2014)27


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For example:

CPB 30303 (JAN 2014)28


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CPB 30303 (JAN 2014)29


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CPB 30303 (JAN 2014)30


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CPB 30303 (JAN 2014)31


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3.4_Deodorization.ppt

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