2 BULLETIN 1413, U. S. DEPARTMENT OF AGRICULTURE 
the butter is the chief consideration, and less care may be exercised 
in the milling operations than when cocoa for human consumption is 
being produced. 
The enormous demand for cacao butter has resulted in a great sur- 
plus of this by-product cocoa press cake, and thousands of tons of 
the product have had so low a market value that some of the 
material has been burned under the factory boilers. Its low price 
has made the cake available for use as fertilizer material, and at 
least two manufacturers of mixed fertilizers have given the product 
a trial as a rough ammoniate filler and conditioner in their mixed 
goods. 
A certain quantity is being subjected to extraction with a fat- 
solvent for the recovery of the cacao fat remaining in the cake after 
the hydraulic pressing, and this solvent-extracted cocoa residue also 
is available for utilization as fertilizer material. The surplus cocoa 
cake has been used as a source of the alkaloidal base theobromine 
and it has also been tried as an ingredient of cattle feed. 
In view of the quantities of these cocoa by-products available and 
the dearth of published information relative to their production, 
chemical composition, and the properties of their nitrogen-bearing 
constituents, an investigation of their nature and their value as fer- 
tilizer material was undertaken. 
THE CACAO BEAN AND ITS PRODUCTS 
SOURCE 
Cacao or cocoa 2 beans, the original source of these by-products 
and of our chocolate, breakfast cocoa, and cacao butter, are the 
separated seeds of the fruit of a tropical tree, Theobroma cacao L. 
Van Hall (19) s states that other species of Theobroma yield beans 
that may be used locally, but only one, T. pentagona Bern., is culti- 
vated. 
This yields the variety known as " alligator cocoa." It is not of 
great importance commercially. Knapp {27) mentions a third 
species, T. sphczrocarpa, but adds that T. cacao produces nine-tenths 
of the world's cacao. 
As received at the manufacturing centers in this country and 
Europe, the beans are ready for roasting, preliminary to cracking 
and the separation of the valuable kernels or nibs from the shells 
and germs. The earlier operations of fermenting, cleansing from 
the fruit pulp, and drying the seeds are invariably performed in 
the country of origin. 
The beans are roasted to develop aroma and improve the flavor of 
the nibs and to make brittle the tough spermoderm or shell. This 
facilitates the breaking of the beans and the subsequent separation 
of the nibs from the shell by-products. 
The relative quantity of nib or shell in the raw cacao bean 
varies with the variety and maturity of the seed and with the pre- 
- Cocoa is the correct English term for the powder used in making the popular break- 
fast drink, but to avoid confusion it is well to adhere to the rule of identifying such 
products as the shells and the butter by the adjective cacao instead of cocoa. ''-Cocoa" 
butter has been confused with coconut oil repeatedly. 
3 The italic numbers in parentheses throughout this' bulletin refer to " Literature Cited," 
p. 41. 
