Flüchtige Säuren in gebräunter Butter

Summary

Aromatic fractions were obtained by high-vacuum thin layer destillation of butter, which had been roasted at a temperature of 145–150° C. The volatile part of these fractions, analysed by gas liquid chromatography, mainly consisted of organic acids, isolated by alkaline extraction or on basic ion exchange resin. The lower fatty acids (butyric, caproic, caprylic and caprinic) were identified and their content in roasted butter estimated to be about 0.5–1 mg/kg each (excepted butyric acid, the content of which was much lower). This result contrasts with the findings in fresh butter, where the content of free fatty acids has been reported to be in the range of only 0.02–0.04 mg/kg each. Maltol (3-Hydroxy-2-methyl-4-H-pyran-4-one), which is formed during roasting, was isolated and identified. It occurs in amounts of 5–15 mg/kg. The significance of these volatile acids as flavor components is discussed.

Zusammenfassung

Es wurden die flüchtigen Säuren untersucht, die beim Bräunen (145–150° C) der Butter entstehen. Dabei wurde gefunden, daß die Gehalte der freien Fettsäuren C₆:₀, C₈:₀ und C₁₀:₀ im Butterfett nach dem Röstprozeß beträchtlich erhöht sind. Maltol (3-Hydroxy-2-methyl-4-H-pyran-4-on) wird neu gebildet. Die Bedeutung dieser Verbindungen als Aromabestandteile wird diskutiert.