UTILIZATION OF WASTE TOMATO SEEDS AND SKINS. 5 



annually could not be obtained. But from the figures given by the 

 firms visited, supplemented by correspondence with other firms, it is 

 estimated that 275,000 tons are pulped annually. Adding to this the 

 tonnage of culls, from which also the seeds and skins could be sepa- 

 rated, a conservative estimate would be about 300,000 tons. 



This tonnage, of course, would vary from year to year. However, 

 owing to the increasing demand for tomato products, the tonnage 

 will tend to increase each year. 



The quantity of wet waste resulting annually would be about 

 16,000 tons, which would yield approximately 3,000 tons of dry 

 waste. This dry waste would yield about 1,500 tons of dry seeds 

 and 1,800 tons of dry skins. 



DRYING THE WASTE MATERIAL AND SEPARATING THE SEEDS. 



An important problem in connection with the utilization of tomato 

 waste is the drying of the mass and separating the seeds from the 

 skins. According to Shriver (14, p. 21-22), this problem is handled 

 in Italy in the following manner : 



The wet seeds and skins are passed through a press to remove as much of 

 the moisture as possible. They are then passed through a desiccator, or drier, 

 in which the material is kept in constant motion by means of horizontal con- 

 veyers, finally emerging from the machine in a dry condition. Heat is applied 

 to the drier by means of steam pipes or by forced air. 



It is stated that about 10 tons of residue can be dried in 24 hours. 

 The final operation consists in passing the dried material through a 

 machine supplied with a series of sieves and fans, which results in 

 the complete separation of the seeds from the skins. 



A number of types of desiccators, or driers, are manufactured in 

 the United States which would be admirably suited for drying the 

 wet waste. It has been suggested that a sugar-beet drier would 

 handle the material efficiently. No great difficulty should be ex- 

 perienced in constructing a separator consisting of sieves and fans 

 for the separation of the seeds from the skins. 



EXTRACTION OF TOMATO-SEED OIL. 



Two methods of extraction are applicable for obtaining fatty oil 

 from seeds. The pressure method is perhaps the simplest and most 

 expeditious, being well adapted to seeds containing a fairly high per- 

 centage of oil. The most careful manipulation of this process, how- 

 ever, leaves a residual portion of the oil in the press cake. The ex- 

 peller type of press is perhaps the best adapted for seeds having 

 a comparatively low percentage of oil. Even with this type of ma- 

 chine a small percentage of oil remains in the press cake. This, how- 

 ever, is not a total loss, since the value of the cake is enhanced by 

 the presence of some fat. A distinct advantage of the pressure 



