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Stearic fatty acid

Abbreviations

  • S

Synonyms

  • octadecanoic acid

Description

Represents an 18-carbon saturated fatty acid. It is highly abundant in animal fats (such as beef tallow and lard) and certain plant fats (like cocoa butter and shea butter).

Nutritional potential:

Stearic acid is unique among long-chain saturated fatty acids because it generally has a neutral effect on blood cholesterol levels. Unlike palmitic or myristic acids, it does not significantly raise “bad” low-density lipoprotein (LDL) cholesterol. This is partly because the human body efficiently converts a significant portion of dietary stearic acid into oleic acid (a beneficial monounsaturated fat) via the desaturase enzyme.

Biodiesel potential:

In fuel applications, stearic acid provides an exceptionally high cetane number (CN) and outstanding oxidation stability (OS). However, due to its very high melting point (approx. 69°C), it is highly detrimental to cold-weather operability. Feedstocks with high stearic acid content (like animal tallows) produce biodiesel with a very high cold filter plugging point (CFPP) and cloud point, causing the fuel to gel and clog filters even at relatively warm temperatures.

References

  1. Hunter et al., 2010
  2. Moser, 2010