Lauric acid


Lauric acid, systematically dodecanoic acid, is a saturated fatty acid with a 12-carbon atom chain, thus having many properties of medium-chain fatty acids. It is a bright white, powdery solid with a faint odor of bay oil or soap. The salts and esters of lauric acid are known as laurates. Lauric acid accounts for nearly half of the fat in coconut oil and palm kernel oil.

Occurrence

Lauric acid, as a component of triglycerides, comprises about half of the fatty-acid content in coconut milk, coconut oil, laurel oil, and palm kernel oil. Oils with high levels of lauric acid are known as lauric oils. Otherwise, it is relatively uncommon. It is also found in human breast milk, cow's milk, and goat's milk.

In various plants

  • The palm tree Attalea speciosa, a species known in Brazil as babassu – 50% in babassu oil
  • Attalea cohune, the cohune palm – 46.5% in cohune oil
  • Astrocaryum murumuru a palm native to the Amazon – 47.5% in "murumuru butter"
  • Coconut oil 47-49%
  • Pycnanthus kombo
  • Virola surinamensis 7.8–11.5%
  • Peach palm seed 10.4%
  • Betel nut 9%
  • Date palm seed 0.56–5.4%
  • Macadamia nut 0.072–1.1%
  • Plum 0.35–0.38%
  • Watermelon seed 0.33%
  • Viburnum opulus 0.24-0.33%
  • Citrullus lanatus
  • Pumpkin flower 205 ppm, pumpkin seed 472 ppm

    Insect

  • Black soldier fly Hermetia illucens 30–50 mg/100 mg fat.

    Uses

Like many other fatty acids, lauric acid is inexpensive, has a long shelf-life, is nontoxic, and is safe to handle. It is used mainly for the production of soaps and cosmetics. For these purposes, lauric acid is reacted with sodium hydroxide to give sodium laurate, which is a soap. Most commonly, sodium laurate is obtained by saponification of various oils, such as coconut oil. These precursors give mixtures of sodium laurate and other soaps.
Lauric acid is a precursor to dilauroyl peroxide, a commercial initiator of polymerizations.

Production and reactions

Lauric acid is mainly isolated from natural sources. Its reactions are representative of those of similar long chain, saturated fatty acids. It can be converted to the symmetrical fatty ketone called laurone. It transesterifies with vinyl acetate. Treatment with sulfur trioxide gives the α-sulfonic acid.

As a dietary fat and cardiovascular risk factor

Lauric acid increases total serum lipoproteins more than many other fatty acids, including LDL and high-density lipoprotein, making it a risk factor for cardiovascular diseases. Lauric acid has been characterized as having "a more favorable effect on total HDL than any other fatty acid , either saturated or unsaturated", which may favor a lower cardiovascular disease risk. However, given the prominence of lauric acid in palm kernel and coconut oil, replacing dietary coconut oil and its high lauric acid content with oils containing mostly unsaturated fats would alter total blood lipids in a way that reduces cardiovascular disease risk.
Although 95% of medium-chain triglycerides are absorbed through the portal vein, only 25–30% of lauric acid is absorbed through this vein.