The most common adulterant of butter is, of course, oleomargarine (q.v.). Unfortunately, the detection of this with absolute certainty is a difficult matter, especially tvlien the proportion is not large. This is on account of the variations in the volatile, fatty in the saponification equivalent, and in other factors of normal butter, due to the feed, to the breed of cows, and to the stage of lactation. The extent to which adultera tion is practiced has thoroughly aroused the dairymen. and it is responsible for the agitation against oleomargarine as a food product. Cotton seed and other oils have been used for adulterat in!__ butter. and attention has recently been called to the use of glucose as an adulterant of butter put up for export to South America. the makers claiming that the glucose was added as a pre servative. A variety of preservatives have been used in butter. especially in inferior butter or in that intended for long shipment. The most usual are mixtures of borax and boric acid. Such preservatives are usually regarded as adul terants.
•11.enovated' or 'process' butter is butter of inferbur quality which has been treated by me chanical and chemical processes to remove the disagreeable taste and odors, and to eliminate its rancidity, and that incorporated with a quan tity of milk or cream to give the mass a semblance of grain and flavor. A great deal of poor country butter is worked over in this way, and considerable of this is sold as good creamery butter. of which it is a fair imitation while fresh.
Although it does not contain any excessive amounts of water or curd, it may well be doubted from its history whether as a food product it is as good as average butterine or oleomargarine.
Foot) VALUE. Butter is w-ed as an article of diet, as a fat for frying, and as one of the in gredients of a large number of foods. Like other edible fats, it is a source of in the diet. of the 0,17 to 11.33 pound of fat required per man per day, according to the amount of work performed. a considerable part may be fur nished by butter, since experience has demon btrated that no fat is more wholesome. In 1S5 American dietary studies, it was found that butter furnished, on the average, 1.9 per cent. of the total food and 10.7' per cent. of the total fat of the daily food.
Butter is very thoroughly assimilated, the co efficient of digestibility of butter-fat being 95 per cent. or over.
Fresh and salt butter arc equally wholesome. Clarified butter is used for a number of culinary' purposes. It is prepared by heating the butter until all frothing and deposition of casein has ceased, and the liquid has become clear and free from water. The butter made in India from -*Mr milk and called glice (q.v.) is often clari fied.