Dimethyl Sulfide and the Flavor of Butter

Abstract

Methyl-sulfide (Me2S) was isolated from butter cultures, cultured cream butter and high quality sweet cream butter in the U. S. and in sweet cream butter in Australia. Identification was established by coincidence of the UV spectra (175-210 m[mu]) after purification by gas chromatography. The average flavor threshold of Me2S in bland butter oil was 24 ppb. A panel of laboratory personnel preferred 40 ppb in bland oil. The proper concentration of Me2S constitutes the "fresh bouquet" of butter and can "smooth out" the harsh flavor of diacetyl and acids in culture flavor. Concentrations in excess of the optimum impart a feed flavor to butter similar to the capeweed taint and alfalfa feed flavor in Australia. Detectable amounts are subject to seasonal variation; higher concentrations are encountered in the spring. The concentration is reduced by vacreation (heating at reduced pressures) of cream, prior to butter manufacture.