Page 28 - FoodFocusThailand No.154 January 2019

SPECIAL FOCUS
SPECIAL FOCUS
Production technology

to minimize trans fatty acids

Trans-fatty acids are types of unsaturated fatty acids that hydrogen atoms at a double
bond in the structure lined on opposite sides of the chain. As a result, the shape of the
molecule is similar to a straight chain with a high melting point, more resistance to high
temperature and high oxidation stability. Trans fatty acids can be found in natural with also
known as ruminant trans fatty, and formed during fat and oil processing, called industrial or
processed trans fatty acids. Trans fatty acids that are harmful to human health caused by partially
hydrogenation process or partially hydrogenated oils (PHOs). If the consumption of such trans fat is
exceeding 1 percent of total energy recommended per day (generally exceeding 2.2 grams), it will raise bad
cholesterol (LDL cholesterol) and lower good cholesterol (HDL). This manner can be a factor increases the risk of
cardiovascular disease. For the natural trans fatty acids found in ruminant meat, milk, butter, and cheese has no
research that indicates a health effect. (Weggemans et al., 2004; Tarrago-Trani et al., 2006)

Previously, partially hydrogenated oils which contain trans fatty acids characteristic and purification. Selecting the type of initial hard fats and liquid
is used for foods that require deep frying such as fried chicken, potatoes oil and the proportions between them, including the type and amount of the
and donuts. It also used as raw material for nondairy coffee creamer or catalyst and reaction conditions are factors that affect the properties of a
whipping cream, including butter substitutes or margarine, and shortening semi-solid fat. The interesterification technology is more complicated than
to be used as ingredients in bakery products. Now, when the use of fractionation and blending of oil processes. The cost is higher, but carrying
partially hydrogenated oil is prohibited by law, the industry must have out a specific semi-solid fat. This technology has now been used more in
modified oil and fat production technology instead of partially semi-solid fat, margarine and shortening productions.
hydrogenation process to reduce the trans fatty acid, and also to maintain Breeding and transgenic oil crops is an effort to alter the fatty acids
a good quality of the food products as wishes. The alternative technology profile in the plant cells in order to get the oil containing desired fatty acids,
includes oil fractionation, oil blending, interesterification, plant breeding, such as inhibited polyunsaturated fatty acid synthesis, and induced saturated
genetic modification, oleogelation and structured emulsion. (Kodali, 2014; fatty acid synthesis, etc. This makes the vegetable oils have a better stability
List, 2014) against the oxidation and have a suitable amount of solid fat for industrial
Oil fractionation applies to oil with high saturated fatty acids, uses after the fractionation. For example, high oleic sunflower seed oil, and
including palm oil, palm kernel oil and milk fat, etc. By reducing the oil high stearic soybean oil, etc.
temperature below its melting point, the oil components that has a high Oleogelation requires a gelator substance, which can be polymers
saturation or melting point will be crystallized. After that, separating the (Polymer-based gelator such as ethyl cellulose) or waxes (Waxes-based
liquid fraction or olein and solid fraction or stearin by means of a gelator such as rice bran wax, carnauba wax, etc.) adding into oils. After
centrifugation or a filtration process. The use of different crystallization heating and lowering the temperature, the oil becomes a semi-solid
temperatures and cooling rates allows the production of olein and stearin substance, with a three-dimensional structure to hold the liquid oil. This
that contain different fatty acids, melting points, and solid fats. For oleogel has a characteristic like a semi-solid fat.
instance, when fractionated method is used for palm oil, the various palm Structured emulsion, however, is to heat up the mixture of liquid oil,
fractions include palm olein, palm stearin, palm mid fraction, palm super co-surfactants, and the saturated monoglycerides until completely dissolved.
olein, and palm hard stearin will be obtained. Each fraction of palm oil Thereafter, add the oil into the water phase, homogenizing the mixture to
is suitable for the use of different products. Oil fractionation is a physical produce the emulsion with smaller oil droplets. By lowering the temperature,
process, which is simple but takes time for fat crystallization. the emulsion system containing the liquid oil droplets surrounded by a multi-
Oil blending is a mixture of hard fat with liquid oil in the appropriate layer structure of monoglycerides will be obtained. As a result, the emulsion
proportion, where the hard fat used can be fully hydrogenated oil, or the has an appearance and characteristic similar to a semi-solid fat, low saturated
stearin from the fractionation. Oil blending could be carried out by heating fatty acids and no trans fat. Although the technology is relatively new, the
the hard fat until melted before mixing it with liquid oil, then, lower the product that certified for Generally Recognized as Safe, GRAS, by the US
temperature according to the controlled conditions to get a semi-solid Food and Drug Administrations has already been commercialized. Such
fat that meets the requirements, including the fatty acid composition, ingredient can be used to substitute the margarine produced by partially
solid fat content, shape, size and type of fat crystals. Recently, oil blending hydrogenated oil in the bakery products. (Wang et al., 2016)
technology has been used in the food industry to replace the partially The above all manufacturing technologies can be used to substitute of
hydrogenated oils for food application as it is a physical process, simple the partially hydrogenated oil to reduce trans fat in food products, but many
practice and low costs. technologies include the fractionation of oil, oil blending and interesterification
Interesterification is a catalytic reaction occurred between fatty reaction have increased saturated fatty acids that can affect health, even
acids and oils or between two or more kinds of oil, such as hard fat and less than trans fatty acids. The development of a technology that provides
liquid oil, etc. The process causes the rearrange of the fatty acid position proper semi-solid fat and good for health is needed for the industry. Regarding
within or between the triglyceride molecules in the oils. This facilitates fat consumption, the consumers must be aware of the balance of fatty acids
the semi-solid fat with a melting property that is suitable for the use of which considering to consume saturated fatty acids to monounsaturated
various products. However, interesterification requires a catalyst, which fatty acids to polyunsaturated fatty acids equal to 1:1:1. In addition, the
can be a chemical substance (Chemical interesterification) or enzyme amount of total fat should not consume more than 65 grams per day for
(Enzymatic interesterification). The fats occurred by this application can Thais, as well as to consume sugar and sodium in an appropriate amount
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be taken into the fractionation process in order to improve a unique for good health.
FOOD FOCUS THAILAND
JAN 2019
26-28_Special Focus-Ku.indd 28 21/12/2561 BE 16:30