Fatty acids are important compounds in food analysis, since they are sample-specific. They can be used as markers or their profile can be used as a fingerprint (e.g., bacteria fatty acids) or to reveal fraud (e.g., seed oil added to olive oil). In GC, fatty acids are analyzed after derivitization to methyl esters (FAMEs). FAMEs is a library of 240 spectra and structures of fatty acid methyl esters, including their Linear Retention Index and calculated Kovats Retention Index. The database contains linear retention index data, registered using an alkane mixture on an apolar column as well as FAMEs and FAEEs (fatty acid ethyl esters) mixtures on a polar one. While other methods such as LC-MS/MS can be used, when using such a highly selective method, technicians can only detect what they are looking for; however, when performing broader TIC screening using GC/MS, no information is lost. Applications include building FAMEs profiles of target bacteria (e.g., Pseudomonas aeruginosa).