[Influence of various temperatures on the essential fatty acid content of butter].

Acid value and fatty acid content were determined in fresh, heat-treated and stored butter. In heat-treated butter, besides the altered acid value also the percentual fatty acid content was changed so that the highest decrease was found with linoleic, linolenic and higher unsaturated fatty acids, whereas the percentual content of palmitic acid increased. The increased acid value and decreased levels of higher unsaturated fatty acids were demonstrated to depend on the height of the temperature used. The results indicate that the probable cause may be the appearance of polymers of unsaturated fatty acids, with higher retention times than the monomolecular fatty acids. In stored butter a decreased unsaturated fatty acid content was found as well, especially in the group stored at +4 degrees C in a refrigerator. A microbiological examination of fresh and stored butter mostly complied with the requirements of Czechoslovak standards (CSN). The results indicated significant losses of the nutritionally important essential fatty acids causing decreased biological butter values at heating, as well as the possibility of employing the method of saturated and unsaturated fatty acid determination for testing the losses at butter melting, even due to other reasons, as e. g. infections.