2. Jesting of the fat.
a) Determination of the melting point in a capillary tube (three days after the fat has been melted into the tube).[232] Pure cacao butter usually melts at 33° C.
b) Determination of the iodine value; usually 35·0 with pure cacao fat.
It is further recommended to make a refractometric determination, which in a Zeiss butter-refractometer must be 46·5° at 40° C.
3. The microscopic test of the substance, from which the fat and the sugar have been removed.
The following are also essential:
I. With cacao mass.
The determination of fibre and ash.
II. Cacao powder.
Determination of moisture at 100° C., of the fibre and ash and examination of the ash (quantitative determination of phosphoric acid and potash).