The Comprehensive Flowmeters Resource


An Antioxidant is a substance that will inhibit oxidation. Antioxidants  are  usually added to fats and oil and provide more stability and longer shelf life by delaying the onset of oxidative rancidity . Something that is rancid has a rank small or taste usually due to a chemical change or decomposition

Processes whereby a pigment, impurity, trace metal- gums and oxidized materials are removed from oils and fats by absorptive cleansing using bleaching clays or activated carbo
The Bleaching of edible oils or fats is generally carried out under vacuum at 158 ºF to 248 ºF

Straight or singles oils/ fats may not be able to satisfy the complexity of  a technical specification desired by a particular product application. By blending or rather  mixing 2 or more straight or modified oils and fats the  the correct balance of properties such as  its melting point,the  plastic range, the color,  the texture and iodine value can be produced or obtained.

A natural constituent that gives crude palm oil its  reddy orange bright color . Carotenes can also be partially destroyed by oxidation under adverse conditions during production, storage and transport of crude palm oil. However in special cases the palm oil can be specially processed to maintain the carotenes. Refining destroys this colour.

Some substances that have a different density will separate by gravitational forces. An example being oil and water . It is well known that oil is lighter than water and easily form a separate upper layer. 
 Rotating the mixture can cause separation in containers. Centrifugation is often used in oil mills and refineries to separate impurities and water from oils and fats and also fat crystals from a fat slurry after addition of a surface-active agent

Chemical Refining
Using alkalis to remove the fatty acids.  Usually caustic soda or soda ash is used alone or in some kind of combination.   Aqueous ammonia can also be used as the alkali in some cases

Cloud Point
This is a test to determine the temperature at which oil begins to cloud as a result of crystallization under controlled cooling. The cloud point is related to the unsaturation of an oil. In general, the higher the unsaturation of an oil, the lower its cloud point will be

Cocoa Fat
This fat has a unique chemical composition, consisting mainly of the triglycerides POS (palmito-oleo-stearin), POP (palmito-oleo-palmitin) and SOS (stearo-oleo-stearin). lt is hard and brittle at ambient temperatures but  can melt quickly  below body temperature. These give chocolate a desirable property 

Cocoa Butter Equivalents (CBE)
These are fats designed to have a glyceride composition similar to that of cocoa butter. Their properties are similar and they are compatible with cocoa butter in mixtures for chocolate manufacture

Cocoa Butter Substitutes (CBS)
These are fats usually based on laurics, i.e. on palm kernel oil or coconut oil. They have snap and melting properties similar to cocoa butter but a different chemical composition. They are not compatible with cocoa butter and the presence of more than 20% cocoa butter in a mixture with them leads to softening and / or bloom formation

Crystallization is the 3 step process of forming crystals and may take place from a melt or from a solution –  The 3 steps are 1)supercooling or super saturation 2) formation of crystalline nuele and  3) the growth of crystals. The process is important for fats in order to produce the desired texture in a solid product, or as a preliminary to fractionation

Fats and oils contain complex organo-phosphorus compounds referred to as phosphatides, or more commonly as gums. They are removed during processing by a variety of treatments collectively referred to as degumming. The process involves treatment with water, or phosphoric acid, or polybasic organic acids, either individually or in combination, followed by centrifuging the precipitated material or by its absorption on a bleaching earth or filter

This process involves removal of certain trace components, present in all edible oils, which give rise to odors and flavors. It is accomplished by the application of heat, steam and vacuum

Fatty Acid Composition
The Triglyceride molecules that make up oils and fats are each composed of three molecules of fatty acids and one molecule of glycerol. The fatty acid composition of a fat or oil is expressed as the percentage of each of the various fatty acids present in the mixture

Fractionation is the process of separation of an oil or fat into two or more fractions. The oil is cooled and crystallized under controlled conditions and the solid separated from the liquid by filtration or centrifugation. Fractionation of a fat is made possible by solubility differences between the component triglycerides. The fractions obtained have different physical and chemical properties from the original oil, and have wide applications

This process involves addition of hydrogen to the double bonds of unsaturated acids in the molecules of an oil. By doing this, the properties of the fatty acids are changed and therefore also the properties and physical behavior of the oil. This chemical reaction is carried out by reacting the oil with gaseous hydrogen at elevated temperature and pressure, in the presence of a catalyst, usually nickel. Hydrogenation of oils and fats is also known as hardening

The fatty acids of palm oil can be rearranged in relation to their position on the triglyceride molecules. The rearrangement, which occurs in a random manner, is conducted in the presence of a catalyst, and is termed interesterification. The rearrangement brings about a change in the physical properties of the oil, which may leave the products more useful for making margarine, vanaspati and shortening

Iodine Value
Iodine value  is a measure of the total number of unsaturated double bonds present in oils or an oil. The determination of  the iodine value involves the addition of halogen in the presence of potassium iodide and titration with standard sodium thiosulphate using starch solution as the indicator

When and oil  or fat is oxidized, the unsaturated fatty acids react and result in rancidity – The most common mechanism of oxidation is a free radical chain reaction – This process is retarded by antioxidants such as tocopherols and tocotrienols – and accelerated by prooxidants such as trace metals and heat. The primary products of oxidation are hydroperoxides. These then decompose into secondary oxidation products such as aldehyes and ketones

Palm Olein
Palm olein is the liquid, more unsaturated fraction separated from palm oil after crystallization at a controlled temperature. The olein consists of a more homogeneous mixture of triglycerides and has properties and uses which are different from those of the original oil

Palm Kernel Oil
This is the oil obtained from the kernel of the oil palm fruit. Its chemical composition is quite different from that of palm oil, which is obtained from the flesh of the palm fruit. Palm kernel oil is a lauric type, similar to coconut oil

Palm Stearin
Palm stearin is the more saturated and more solid fraction of palm oil. Its fatty acid composition is variable depending on the process employed to isolate it, ranging from 53% to 88% for saturates, 16% to 37% for monounsaturates, and 3% to 10% for polyunsaturates. Palm stearin is used in formulating products that require a higher degree of saturation, such as margarines and shortening

Physical Refining
Physical refining may be defined as the taking away (removal) of free fatty acid from an oil by the action of high temperature , high vacuum and live steam. lt is also referred to as steam refining and  this process is normally carried out in a single step with deodorization

Polyunsaturated Fatty Acids (PUFA)
These are fatty acids having two or more double bonds in their carbon chain. The most common polyunsaturated fatty acid is linoleic acid. Corn oil, sunflower oil and soyabean oil are some vegetable oils that are rich in PUFA

Rancidity is a condition in which an off-flavor has developed in edible oils or fats, or manufactured food products; it is caused by oxidative deterioration. Primary oxidation products are odorless and tasteless but certain secondary decomposition products have particularly potent off-flavors and are detected by the palate at extremely low concentrations. The term rancidity is sometimes also used to describe the soapy taste resulting from the hydrolysis of lauric oils, which is due to the short chain fatty acids formed


  All crude oils and fats when freshly produced contain unwanted impurities. These consist essentially of free fatty acids, gums, trace metals, odoriferous materials and water. The various processes used to remove all these entities are normally known collectively as ‘refining’


Slip Melting Point
Fats consist of a complex mixture of glycerides and therefore do not have sharp melting points, unlike pure chemical substances. The slip melting point of a fat is defined as the temperature at which a column of fat in an open capillary tube moves up the tube when it is subjected to controlled heating in a waterbath. Because of their polymorphic behavior, the slip point of some fats is dependent on the previous treatment of the sample

Fat splitting is usually carried out with steam at high temperature and pressure (e.g. 260 ‘C and 55 bar) to give glycerol and a mixture of fatty acids. This process opens the gateway to the oleochemical field

In the chemical refining of crude oils, the free fatty acids are removed by neutralization with alkali and settle to the bottom as alkali soaps, known as soapstock

Stearic Acid
Chemically, stearic acid is an 18-carbon saturated fatty acid. Commercially, the term is used for mixed solid acids of various compositions. Stearic acid is used for industrial purposes in the rubber and oleochemical industries

Trans Fatty Acids
Trans fatty acids are formed during the partial hydrogenation of an oil. Some of the unsaturated fatty acids present are changed from their natural, bent cis shape to a straight trans shape like that of the saturated acids. In consequence, many of the physical properties of trans-acids, such as melting point, are nearer to those of the saturated acids, although double bonds are still present

Tocotrienols & Tocopherols
These are components of Vitamin E. In both unprocessed and processed forms, palm oil has significant concentrations of tocopherols and tocotrienols. Both act as powerful nutritional antioxidants, probably helping to reduce cellular damage due to oxidative metabolism, as well as that resulting from the action of toxic chemicals and pollutants in our environment


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