234 HETOKT OF OFFICE OF EXPERIMENT STATIONS. 



Many ngrioultural products are of such a nature that they can not 

 be uiclcly distrihutctl without protection against deterioration. The 

 decay of animal and ve<>ctal)le food materials is due to the activity of 

 bacteria which j^ain access to them from many sources, and increase 

 rapidly under suitable conditions of moisture, tenij)erature, and 

 absence of substances injurious to the orpmisms, Metliods of preser- 

 vation of food depend upon the prevention of the growth of the 

 bacteria, either by destroying them, b}' keeping the material dry or 

 cold, or by adding some antiseptic. A number of experiment stations 

 have studied methods of storing apples, potatoes, and other common 

 vegetables and fruits foi' home use and for market purposes, and in 

 connection with this work have investigated the causes of decay and 

 similar })roblems. 



Very many products, such as fruits and vegetables, which are perish- 

 able in the fresh state may be kei)t indefinitely when dried. This 

 method of preservation has several advantages, in that it is relatively 

 inexpensive and may be practiced in a small way as well as commer- 

 cially. Furthermore, in drying, the nuiterials decrease in bulk and 

 weight and the cost of distribution is thereby materially reduced. 

 Objection to the method is that the food materials are usually not 

 preserved in their natural condition, and their flavor is sometimes 

 lost, and in some cases preliminary soaking or cooking before use is 

 necessary. With many products, however, the advantages are more 

 than the disadvantages. At the South Carolina Station " some prob- 

 lems connected with the production and distribution of the sweet 

 potato were investigated. It had been demonstrated that large crops 

 of this vegetable could be produced, but they could not be marketed 

 successfully because in their condition as harvested they were too 

 perishable and would not bear rough handling and exposure to cold 

 weather. The station devised a simple method of drying the pota- 

 toes so that they w^ould keep indefinitely, and might be handled and 

 distributed much more easily and cheaply. The successful introduc- 

 tion of such a method means a wider distribution and a more ex- 

 tended use of this nutritious farm product. At the Oregon Station ^ 

 investigations were made on the methods of preventing discoloration 

 of evaporated fruits and vegetables. 



Many food materials are preserved by storing at low temperature, 

 at which the organisms that cause decay will not thrive; but unless 

 natural means for maintaining low temperature can be utilized this 

 method is too expensive for general use. It is applied in a commei- 

 cial Avay to the preservation of meats, butter, eggs, vegetables, and 

 other food products. This has been the subject of investigation at 

 several of the stations. The North Carolina,'^ North Dakota,"* and 



« South Carolina Sta. Bui. 71. 

 6 Oregon Sta. Rpt. 1903. 

 c North Carolina Sta. Bui. 191. 

 d North Dakota Sta. Bui. 44. 



