The lactone content of butter, fermented butter, and margarine was compared using gas chromatography-mass spectrometry. The main lactones in butters and fermented butters consisted of δ-decalactone, δ-dodecalactone, δ-tetradecalactone, δ-hexadecalactone, and γ-dodecalactone. In contrast, the main lactones in margarines were δ-decalactone and δ-dodecalactone. The total lactone content in butters and fermented butters increased by approximately two-fold upon heat treatment, whereas, heat treatment did not affect the lactone content in margarine. The changes in lactone content caused by heat treatment were greater in fermented butters than in butters. These findings suggested that the fermentation process could increase lactone or lactone precursor content in butter.
Keywords: gas chromatography; lactones; milk fat; quantification.