Thursday 5 August 2021

Go to goaty

Friends [home-ed, Birkenstocks, rice-cakes, GIY] of ours kept goats when their kids were small. The milk was acceptable so long as it was super fresh and cold. After a day or two, even in the fridge, the girls would screw up their faces at the whiff. That same child-challenging aroma is what makes goat cheeses an interesting addition to the cheese-board. There are three medium-chain fatty acids whose name is derived from Capra hircus. Fatty / carboxylic acids all have a carboxyl COOH group at one end which is quite reactive and dietary "fat" typically attaches the COOH to glycerol leaving a chain of hydrocarbon hanging off the end. 

  • capric acid aka decanoic acid has ten carbons [MP 31°C]
  • caprylic acid = chain 8 C long [MP 16°C]
  • caproic acid = chain 6 C long [MP -4°C]

All three of these goaty fatty acids are "saturated" - all the carbons are fully charged with hydrogens. Saturation and length both contribute to solidifying the acids and their compounds. The melting points in the list above imply a linear relationship between chain length and MP, but it's more complicated than that with acetic acid being solid at roomish temperature. Unsaturated fats have double bonds between some of the carbons making them a bit more flexible and less viscous. For completeness, I've mentioned SCFAs in a takedown about the number of diets which depend more on assertion than evidence. SCFAs have fewer carbons in the side chain: formic C; acetic CC; proprionic CCC; butyric CCCC [as in butter]; valeric CCCCC.

Mammal milk is widely different in fat content, let alone exactly what fatty acids are present, and there is some evidence that MCFAs are anti-fungal and/or pre-biotic - encouraging the growth of good gut bacteria. Capric acid is also found in plants; especially coconut [10%].  If you have a well-trained microbiome, then high fibre diets will naturally ferment to produce a) SCFAs and b) gas. If you are a) 12 years old b) a boy it is therefore acceptable to talk about short chain farty acids. Note kids are adorable.

No comments:

Post a Comment