Skip to main content
ARS Home » Research » Publications at this Location » Publication #204520

Title: Enrichment of decanoic acid in cuphea fatty acids via distillation

item Cermak, Steven - Steve
item Durham, Amber
item Evangelista, Roque

Submitted to: Industrial Crops and Products
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/20/2007
Publication Date: 4/30/2007
Citation: Cermak, S.C., John, A.L., Evangelista, R.L. 2007. Enrichment of Decanoic Acid in Cuphea Fatty Acids via Distillation. Industrial Crops and Products 26(1):93-99.

Interpretive Summary: Distillation, which uses heat and reduced pressure, was used to help remove unwanted materials from the fatty acids of a new U.S. crop called cuphea. One of the current problems with cuphea is it contains unsaturation, which makes the material undesirable for cosmetic and lubricant applications. Typically, unsaturation is desired in food applications and the saturated materials are considered undesired. With the help of a lab molecular still, which is just a complex distillation unit, our lab was able to develop new ways to help purify this new crop. Distilled cuphea-like compounds are currently used in shampoos, conditioners and bio-based lubricants. These products are very mild on the environment because they biodegrade, which means they break down, dissolve and disappear once they enter the rivers or landfills. By inventing new and better ways to get cuphea into the cosmetic and lubricant industries, we can feel better about our environmental impacts with the use of such products.

Technical Abstract: The introduction of a new crop often requires the development of new products and purification techniques of either the oil or fatty acids. Most new crops enter the cosmetic market first due to their high rates of returns. However, the cosmetic market often demands high purity and colorless materials. A molecular distillation unit is a powerful method of separation; separation occurs at extremely low pressures and, therefore, at reduced temperatures compared to normal distillations, which makes it very suitable for cuphea fatty acids. Refined cuphea fatty acids, which are mainly short chain saturated fatty acids, such as decanoic acid (C- 10), were distilled using a lab scale centrifugal molecular distillation unit to yield a distillate that was colorless (Gardner Color = 1-). The optimal distillation conditions were explored by varying the rotor temperature and flow rate onto the rotor. As the conditions were varied, the distillate and residue was monitored for Gardner color, fatty acid composition and mass split rate between distillate and residue. Under a high flow rate (2.23 g/min), enrichment of C-8 and C-10 in the distillate was increased to 96% in a single-pass distillation (rotor temperature = 65EC) with no unsaturation in the distillate while maintaining a split ratio of 1.5. A high flow multiple-pass distillation (rotor temperature = 70EC) of a distillate fraction produced a distillate that was 99.8% saturated fatty acid and 0.2% unsatured with very high split flow ratios. Overall, laboratory distillation of cuphea fatty acids successfully demonstrated the ability to achieve either high percents of C-8 and C-10 or total saturated samples.