The Acid Degree, Free Volatile Fatty Acids, and the Flavor Score of Salted Commercial Butters

Abstract

Summary The existence of a possible relationship between butter quality and free fatty acid concentration, including those of a volatile nature, was investigated. Methods involved included the Knaysi-Guthrie method on butterfat, a titration method for acid degree, and a modified ether-extraction direct-distillation technic for free volatile fatty acid concentration in butter and butterfat. Free volatile fatty acid concentration of butter determined either as total or water-soluble acidity was found, in general, to be inversely related to the flavor score of 69 lots of salted commercial butter. Individual samples varied appreciably from the averages. The relationship between the acid degree and the butter score was not well defined. An inverse relationship was discernible but individual samples varied greatly. It was not possible to observe the existence of a close relationship between the flavor score of commercial butter and the Knaysi-Guthrie number of butterfat, even in average values, except that very high-scoring butters generally gave low values. On the basis of the data obtained, it would not be advisable to recommend using either the free total acidity or the free volatile fatty acid values of butter as an index for determining flavor scores of salted commercial butters, due chiefly to variation of individual samples from the averages. For a rough classification of commercial butter as excellent, good, fair, or poor, the use of free volatile acid values might have merit. However, the accumulation of much more data would be required before even this rough classification could be established.