224 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



Tliey are now being used satisfactorily on a large commercial scale, 

 and while there will always be unsolved problems, as in every chem- 

 ical industry, the methods of manufacture of citric acid are suffi- 

 ciently well developed to permit its manufacture from the raw prod- 

 uct at a fair profit to the lemon grower. 



When these investigations were begun there were but one or two 

 struggling by-product companies in California, which Avere making no 

 appreciable inroad into the enormous supply of cull fruit available. 

 After a few years' work and the expenditure of less than $100,000 this 

 situation has materially changed. Four stable, going concerns, three 

 of them privately owned, and one a cooperative growers' company, are 

 now^ manufacturing lemon by-products. The total annual manu- 

 facturing capacity of these plants is over 1,500,000 pounds of citric 

 acid, over 500,000 pounds of citrate of lime, and over 50,000 pounds 

 of lemon oil. Some 20 concerns may be said to be producing orange 

 by-products on a considerable scale. The products consist largely of 

 marmalade, about 50 per cent of which is produced by one coopera- 

 tive company. Marmalade stock, jellies, and candied peel are also 

 being made in smaller quantities. The total output of orange by- 

 products for the present year will approximate 6,000,000 pounds, 

 troof of the advance which has been made since this project began 

 is the increase in the price of cull fruit. Less than five years ago cull 

 lemons could be had in large quantities at $5 a ton ; to- clay advertise- 

 ments appear in several agricultural papers offering from $20 to 

 $25 a ton for the same material, in face of the fact that a larger quan- 

 tity is now available. The same situation exists in the case of oranges. 

 In former years $5 would buy a ton of sound cull oranges ; the price 

 at the present time for sound culls is from $20 to $30 a ton. 



The by-product laboratory has been in close touch with a great 

 majority of the by-product manufacturers, advising them as to proc- 

 esses and assisting them in every possible way in establishing their 

 business. No small amount of good has been accomplished in point- 

 ing out defects in proposed methods of operation, and much money 

 and time has thus been saved investors and experimenters in this 

 field. 



Work upon the production of citrus by-products was also done in 

 Florida during the year, and it is proposed next season to prosecute 

 the Florida part of the project vigorously. 



DEHYDRATION OF FRUITS AND VEGETABLES. 



The special appropriation for dehydration did not become available 

 till late in the fall, when the production of fruits and vegetables is 

 small. The work that could be undertaken was therefore somewhat 

 limited, and in consequence a considerable proportion of the funds 

 available was not used. During the war a number of plants were con- 

 structed by private enterprise to dry fruits and vegetables for military 

 purposes, but the majority of the products, while nutritious, were un- 

 attractive and inferior in quality. The bureau endeavored to investi- 

 gate all the processes in use, in the hope of suggesting improvements 

 whereby satisfactory dried fruits and vegetables might be produced, 

 and a sound, permanent industry established. To this end all the 

 larger plants were carefully inspected, and their processes studied 

 under commercial conditions. Numerous conferences Avere held with 



