Butter is a fatty product where the aqueous phase is dispersed in oil phase forming a water/oil emulsion. The physical and chemical analysis determine the occurrence of hidrolysis, rancification or adulteration in the oil phase. The improper addition of other fats in butter formulation, in order to reduce costs, causes a modification of the oil phase physical and chemical characterisitics. Five brazilian and two imported commercial salted butter brands, classified as "extra", were used to evaluate the quality of the butter commercilalized in Rio de Janeiro State. A total of 66 samples were submitted to acidity, peroxides value, iodine value, water content, sodium chloride content and fatty acid profile analysis by GLC. Results for acidity were in 0.76 and 2.03 SN%; for peroxides values were in 0.15 and 3.82 mEq/kg fat; for iodine value were in 20.76 and 53.46 g I2/100g fat; for water content were in between 11.3 and 20,3%; for sodium chloride content were in 0.14 and 2.21%; for principal fatty acid were in C14:0 (9,7-12,1%); C16:0 (22,0-26,1%; C18:0 (9,6-11,7%) e C18:1 (21,9-24,2%. The acidity of all samples were in expected range; 85,5% of samples were found to have peroxides value upper to the permitted by legislation; 15.2% of samples were out of iodine value range permitted; 34.8% of samples were found to have water content upper to the permitted by legislation; 7,5% of samples were found to have sodium chloride content upper to the permitted by legislation; and fatty acid profile were in expected range.
butter; quality control; brazilian legislation patterns