Page 32 - HPIC E-Magazine (January-2021)

Special Article Special Article

Use of vegetable oils as alternatives to animal fat used only in less developed countries ture, and so their usage limited. Top important vegetable oil used in soap
today for large-scale manufacture.
white (TW) and Fancy Bleachable manufacture. Its main contribution is
for soap making (BF) grades of tallow are used for to improve solubility and foam pro-
Nowadays, soaps are made by soap manufacture. Both these grades perties of the soap manufactured. Co-
fatty acid neutralisation. Fats and oils of tallow are very similar to edible conut oil is usually mixed with other
Introduction are split at high pressure and tempera- grade tallow and yield high quality non-lauric oils like animal fat, frac-
Oils and fats, either from plant or ture by water to give fatty acids and soap, but at a lower price. tions of other vegetable oils, marine
animal origin, are a basic raw mate- glycerine. Apart from economic ad- oils, hydrogenated oils, etc., to make
rial used in soap manufacture. Com- vantages obtained from this process Fat obtained from hogs and fowls soaps.
monly used ones include animal tal- the lower boiling fractions of fatty ac- are called as Choice White Grease
low fat, and vegetable oils obtained ids can be removed for the fats and (CWG). They are unstable due to the While tallow is the primary fat
from palm oil, coconut oil, palm ker- oils to give truly superior fatty acids high unsaturated fatty acid content raw material used in soap making all
nel oil, groundnut oil, rice barn oil, for use in making soap. and are used for cheaper quality toi- over the world, coconut oil is often
castor oil, etc. let and laundry soaps. For making added to improve the quality of soap
Use of tallow as raw material toilet soaps, tallow used should be and to obtain soap that has superior
Natural triglycerides are formed Tallow is the most widely used as white as possible. The whiter the foam and performance characteri-
with different mixes of fatty acids. It animal fat in soap manufacture. The tallow, the brighter the colour of the stics. In regions where tallow is not
is important for a soap manufacturer quality of tallow depends on the type soap obtained. available, other locally available fatty
to know the type and the amount of of treatment carried out. Natural de- substances are used as substitutes.
the fatty acids present in different and palm oil contain longer chain Soft oils are hardened by catalytic composition of tallow begins with the Good quality tallow when used in In tropical regions like Malaysia and
oils as it is these fatty acids that saturated fatty acids and soaps made hydrogenation and bleached to im- slaughter of the animal. The colour and soap making requires lower amount Indonesia, for instance, palm oils and
determine the property of the soaps from these fats are firm, slowly solu- prove the properties of soap. There is content of the fatty acids increase with of opacifiers, and lower optical palm stearin is used as a replacement
made out of them. Moreover, this ble, milder and have a good deter- usually a loss of natural antioxidants time to yield poor quality tallow, if no brightener levels. The fragrance level for tallow, whereas in other regions,
knowledge also gives good flexibility gency. found in the oil during the process of treatment is carried out. All care has requirement is also lower, as smaller it is replaced by vegetable oils ob-
to the soap maker in replacing and/or bleaching and hydrogenation. Anti- to be taken during rendering, hand- amounts are required to mask the tained from local plant sources that
substituting oils in the soap oil blend Lauric oils like coconut oil and oxidants may be necessary to prevent ling, and storage of the fat, so that base odour. Also fragrance stability are partially or totally hydrogenated
according to market factors of avail- palm kernel oil, have shorter chain rancidity developing in the oils and degradation is prevented and the fat in the soap is better if superior qua- and sometimes split and distilled.
ability and cost. fatty acids, which form soap that give in the soaps made out of these oils. remains good for soap manufacture. lity animal tallow is used.
faster, tighter more copious lather, Excess linoleic acid and linolenic acid Options for India
Soap is the alkali salt of a fatty acid and are less mild than soap from hard in soap oil blend is not advisable, as Tallow is obtained by putting Toilet soaps usually contains India, a predominantly Hindu
with a general formula NaOOC(CH ) fats. they develop rancidity faster. the animal tissue containing the fat 10-30% lauric oils (coconut oil, palm country, strongly believes in non-vio-
2 n
CH . Soap properties exist when n+2 through a process called rendering. kernel oils, etc.) Coconut oil is the most lence against all living beings. In line
3
is greater than 8 and less than 20. Soft oils like groundnut oils, cot- In soap making, raw materials are Rendering consists of separating the Table 2
The best properties occur when n+2 ton seed oils, rice barn oils, contains chosen based on the quality para- fat & tissue from water using heat and Fatty acid compositions & properties of commercial palm based soaps
is in the range 12 to18. more unsaturated fatty acids. Soaps meters required to ensure high quality pressure. Rendering can be carried
made from these oils are softer, less products at the required price. The out by two methods namely wet and Fatty acid % weight Properties Values
Types of fatty acids & oils white and less stable. quality parameters include saponifi- dry. When taste, colour and odour are compositions
The fatty acids used to make cation value, acid value, titre value, important parameters then the wet 08:0 Less than 1.0 Iodine value 39.0 to 43.8
soap are obtained from fats and oils. Table 1 iodine value, Lovibond colour, etc. It method is preferred for extracting
The fatty acids have varying chain Important fatty acids for soap can be clearly seen that a judicious edible animal fat. Dry method is used 10:0 Less than 1.0 Titer °C 39.2 to 43.2
lengths, which are all straight chain manufacture blend of oils and fats are necessary for non-edible quality animal fat. 12:0 7.0 to 14.0 % Free caustic alkali Less than 0.1
and contain even number of carbon to obtain soap with ideal properties. 14:0 3.5 to 6.0 % Moisture 6.9
atoms. There are about 40 different Fatty acid Carbon atoms It is also necessary to blend different Edible quality fat has a low colour
fatty acids occurring in nature – the Lauric acid 12 oils for economic reasons. The blend and free fatty acids levels and is gene- 16:0 3.7 to 44.7 Penetration value (mm) 19.0 to 32.0
largest is the group containing 18 Myristic acid 14 is so adjusted to control hardness, rally used to make food products for 18:0 3.7 to 4.2 % Salt (NaCl) Less than 1.0
carbon atoms. Palmitic acid 16 plasticity, lather, mush, cracking, human consumption. The consump- 18:1 30.0 to 33.3 % Total Fatty Matter (TFM) 83.0 to 86.0

The last four fatty acids are un- Stearic acid 18:0 mildness and discoloration. tion of animal fat by humans is re- 18:2 6.5 to 7.5 Foamability (ml) (immediate) 460
ducing largely due to health concerns
saturated fatty acids. These give Oleic acid 18:1 Soap making process and evolving consumer preferences. 18:3 0.10 Foamability (ml) (after 295
softer soaps with lower melting point Linoleic acid 18:2 Direct saponification of fats and Soap made out of edible quality tal- 5 minutes)
and are less stable. Linolenic acid 18:3 oils with caustic soda is the original low (ET) is the best both in terms of 20:0 Less than 0.5 Hunter Whiteness (%) 81.4 to 86.4

Hard fats like, mutton tallow, lard Ricinoleic acid 18:1 method universally used world to pre- performance and aesthetics. However, Others 0.2
pare soap. However, this method is
they are expensive for soap manufac-
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