Approaching Chemistry: Saponification of a Triglyceride

Do you like using handmade soap? Handmade soap can also be added with various additives such as essential oils according to personal preferences and purposes, or made into the shape you like. It can also be formulated separately according to your skin type. Do you know how soap is made? What is the saponification of a triglyceride? Come and study with me.

What is saponification?

Saponification is a chemical reaction named after its important step in the soap manufacturing process. The discovery and application of saponification reaction can be traced back to ancient times. Around 3000 BC, the Sumerians created the prototype of soap. It describes the process by which oil and water, such as potassium or sodium hydroxide, conduct a hydrolysis reaction to make soap in an alkaline environment. To ensure the rate of reaction and the quality of the product, appropriate temperature and pH values are required for the reaction.

The milligrams of potassium hydroxide required for complete saponification of 1 gram of oil in the industry is called the saponification value of the oil. This is one of the important constants for testing the quality of fats and oils. Because of the existence of impurities that cannot be saponified, impurity fats have a reduced saponification value. Superior oils and fats, on the other hand, will have a greater saponification value.

Saponification reactions have a wide range of applications. One of the most popular cleaning products is soap. Other cleaning products, such as hand sanitizer, laundry detergent, and shower gel, are also created using the saponification reaction concept. This reaction has also been widely utilized by the industrial sector. For example, the fatty acid sodium that is created during this reaction may be used to soften, smooth, and increase the waterproofness of leather products. Biomedicine is another field that makes use of it. Moreover, it may be applied to industrial wastewater treatment to eliminate dangerous compounds.

Saponification of a Triglyceride

Triglycerides react with alkali in a process known as the saponification reaction to produce soap and glycerol. A process called hydrolysis is responsible for breaking down triglycerides in an organism into glycerol and water. When triglycerides react with an alkaline solution such as potassium or sodium hydroxide, they produce glycerol, soap, and a fatty acid salt. This process is known as saponification. Triglycerides are usually animal fats or vegetable oils, and by reacting with potassium hydroxide, a soft and smooth soap can be obtained.

Saponification of a triglyceride mechanism was discovered by French scientist Eug è ne Chevreul in 1823. The reaction principle is that when solid sodium hydroxide is dissolved or diluted with a concentrated solution, it will release heat and react with inorganic acids to generate corresponding salts, which can precipitate metal ions from aqueous solutions into hydroxides and cause saponification reactions in oils and fats. Because ester bonds are easily broken under alkaline conditions, one hydroxyl group forms glycerol, the other generates fatty acids, and under alkaline conditions, sodium salts are formed, which is soap.

The saponification reaction of triglycerides uses sodium hydroxide. Is it safe to use sodium hydroxide to make soap? If theoretically speaking, the final products obtained from saponification are sodium fatty acids and glycerol. Handmade soap preserves the by-product of the saponification reaction - glycerol, which is an important substance for moisturizing the skin. This is also one of the reasons why handmade soap is called pure natural. Also, because the saponification reaction produces solids, it is relatively easy to store and less susceptible to microbial infection. It can be preserved without adding preservatives or fungicides. The production process of low-temperature cooling can also retain more natural beneficial ingredients.

However, the saponification reaction is not a complete reaction, and in addition to the product, it will inevitably leave unreacted fats and caustic soda. After the soap solidifies, the contact area between the solid oil and sodium hydroxide is much smaller than the contact area between the two in the liquid, so free alkali will appear in the solid soap.

Conclusion

In conclusion, we explore the subject of “saponification of a triglyceride”. Overall, it is the saponification reaction of sodium hydroxide and triglycerides, and the product is soap. This reaction can be completed at home if operated properly, but be careful of the large amount of heat generated during the reaction process to avoid skin burns.