Published online by Cambridge University Press: 01 June 2009
1. The fatty acids have been isolated from six samples of butter made rancid with pure cultures of bacteria and moulds, and from six samples of naturally rancid butter.
2. The fatty acids have been fractionated into volatile, solid and liquid groups.
3. The mould samples produced in every case a greater total of fatty acids than bacteria under identical conditions.
4. Bacteria produced relatively less volatile acids than moulds but slightly more solid acids.
5. Of the volatile acids produced it appears that bacteria produce a greater proportion of butyric and caproic acids than moulds.
6. The liquid acids make up by far the greatest proportion of the fatty acids recovered, being in each case between 77 and 85% of the total. Of these, oleic and linoleic probably comprise the majority.