BUTTER DEFECTS 491 



to six weeks to become pronounced under commercial condi- 

 tions of handling butter. Tallowiness is not a usual cold stor- 

 age defect of butter. In commercial cold storage, butter seldom 

 goes tallowy. This defect develops primarily in butter lying 

 in stores and exposed to rather high temperatures (room tem- 

 perature). Tallowiness is more prevalent in print butter than 

 in tub butter. The tallowy flavor and the bleaching start on the 

 surface of the butter and gradually work into its interior. But- 

 ter may have turned very tallowy and perfectly white on its 

 surface, while the core of the package may still have the nor- 

 mal yellow color, and be free from the tallowy flavor. 



Causes of Tallowy Flavor. Tallowiness, similar to ran- 

 cidity, is due to a decomposition of the butterfat. These two 

 flavor defects often occur in the same piece of butter and have 

 frequently been confused, or considered synonymous. This con- 

 fusion is unfortunate, inasmuch as it has led to misleading in- 

 terpretations of experimental results, rendering difficult the 

 establishment of their true causes and hindering efforts in- 

 tended toward their prevention. 



A careful study of the causes of tallowy butter shows that, 

 unlike rancidity, which is the result of hydrolysis of the fats, 

 tallowiness is due to oxidation. 



On the basis of our present knowledge 1 relating to tallowy 

 butter, the causes and prevention of this defect may consist- 

 ently be summarized as follows: 



1. Oxidation the Cause of Tallowy Butter. The butter 

 defect known as tallowy odor and flavor is the result of a 

 process of oxidation. The oxidizing action may, or may not, be 

 on the fat, according to agencies and conditions favoring the 

 oxidation, as outlined in succeeding paragraphs. 



2. Exposure to Air, Light and Heat. Air readily brings 

 about oxidation of the fat in butter, and this oxidation is 

 greatly intensified in the presence of light and heat. Butter 

 so exposed is prone to rapidly develop a tallowy flavor. This 

 fact is well known to the layman. Tallowiness, caused through 

 these channels, is comparatively rare, because the great bulk of 

 commercial butter is guarded against these agents. The wrap- 



a Hunziker and Hosman, Tallowy Butter, Its Causes and Prevention. 

 Journal of Dairy Science, Vol. I., No. 4. 1917. 



