================+=========+============ | | Refractive | Acid | index | value | in Zeiss’s | | butyrometer ================+=========+============ | | 46-47·8 Cacao butter |9·24-17·9| at 40° C. | | Oil of Almonds | — | 64-64·8 | | at 25° C. Sesame oil | — | 67-69 | | at 25° C. Earth-nut | | (Arachis) oil | — | 65·8-67·5 | | at 25° C. Hazelnut oil | — | — | | Cotton-seed oil | — | 67·6-69·4 | | at 25° C. Oleo-margarine | — | 48·6 | | at 40° C. Beef tallow | — | 49 | | at 40° C. Wax | 19-21 | — | | Paraffin | — | — | | Stearic acid | 195-200 | — | | Sebin | — | — | | Cocoa-nut fat | — | 35·5 | | at 40° C.
The presence of cocoa-nut fat can also be shown by the etherification of the fatty acids with alcohol and sulphuric acid, when the characteristic odour of the ester of cocoa-nut acid occurs. Vegetable oils, such as almond, cotton-seed, arachidic, sesame and hazelnut oils, lower the melting point of the fatty acids and raise the iodine value. Sesame oil is easily detected by Baudouin’s reaction, yielding a raspberry coloration whilst pure cacao butter keeps a fine yellow or dark brown. It is possible to detect the presence of so minute a quantity as 1% of sesame oil, by means of Baudouin’s reaction.
The following table, containing the analytical determinations of all fatty substances which can possibly be employed in the adulteration of cacao butter, will serve to facilitate reference to this subject.
In addition to its use in the manufacture of certain cacao preparations and for lubricating parts of machinery which come into contact with the cacao etc. cacao fat is also used in perfumery and especially in pharmacy for making suppositaries, ointments, etc., but it is of no importance in soap making. As an edible fat, in the true sense of the word, like ordinary butter or lard, cacao butter is not used. It has been maintained by Benedikt[48] that when in the form of chocolate it is as easily digestible in the human organism as milk fat, which is generally regarded as offering most favourable conditions for absorbtion in the intestinal canal. The digestibility of both fats varies from 92·3 to 95·38 percent, and both, in this respect, stand very near to cocoa-nut fat from which the solid glycerides have been removed, and to ordinary butter, the former according to Bourot and Jean.[49] being digestible to the extent of 98 and the latter 95·8 percent.