66 BULLETIN^ 196, U, S. DEPARTMEISTT OF AGEICULTUEE. 



utes. Some experiments were made on using temperatures above boiKng for a shorter 

 period, but as the temperature rises above 220° F. the color becomes darker. 



The canning of sweet potatoes is still in an experimental state, as brokers and job- 

 bers have demanded an appearance which has been attained for the most part by 

 overfilling and which is prone to produce springers. These are sound and whole- 

 some as food, but the can presents an appearance which makes it unmerchantable 

 and, unlike products containing liquid, a part can not be ^vithdrawn and the can 

 resealed. 



Tomatoes (Lycopersicon esculentum). 



The time is easily within the memory of many persons when tomatoes were thought 

 to be poisonous. A few persons in the Eastern States used them 70 years ago, but 

 they did not become common until a much later period. In the West the prejudice 

 against them persisted until less than 40 years ago. The first record of canning toma- 

 toes is that of the work done by Harrison W. Christy in 1847 at Jamesburg, N. J. 

 Tomatoes are now used in enormous quantities in the fresh state and head the list 

 of all vegetables as a canned product. Thousands of bushels are also used in the 

 manufacture of ketchups, chili sauce, and soups. The tomato is produced over a 

 larger part of the United States than any other vegetable. It may be handled with 

 few and simple appliances, and may therefore be canned in the home and in small 

 factories where Little capital is required, as well as in the large factories. 



The development of a tomato suitable for canning purposes has been a specialty 

 in itself. For canning the fruit should be moderately large, smooth, so that it will 

 peel readily, ripened evenly to the stem, of a clear, red color, and having a large 

 proportion of solid meat of good flavor. Varieties which ripen unevenly or are irregu- 

 lar in outline are difficult to peel and the percentage of waste is too high. Tomatoes 

 which are yellow or purple do not have an attractive appearance on opening, and 

 those with excessive seed cells or which are soft and watery will give the can the 

 appearance of being slack filled or packed with water. A good pack is therefore 

 dependent upon ha\'ing a variety possessing the right qualities. The canner can not 

 accept tomatoes of a half dozen or more varieties and get good results. He must there- 

 fore specify the variety gi-own or furnish the plants for his growers. The production 

 of plants in hotbeds and cold frames to supply several himdred acres is of itself a 

 very large task. The plants are grown in the field, the same as other crops, and a 

 single large cannery will use the product of 1,000 acres. One ketchup manufacturer 

 takes the entire product from more than 5,000 acres. A fair yield is 5 tons of fruit 

 for an acre, but good cultivation and fertilization sometimes brings this up to 20 tons 

 or more. Thirty-three bushels weigh about 1 ton. 



At harvest time the fruit must be picked every day, or every other day, in order 

 to insure collecting it when it is in its prime — just ripe, without green butts, and not 

 overripe. It is preferable that the tomatoes be put in crates which are wide and 

 flat rather than deep, and which will hold not more than a bushel. They can be 

 delivered to the factory in better condition in the flat crates than in the deep ones 

 or in baskets, as the fruit will crush if piled in too many layers. Arrival in good con- 

 dition lessens the time required for peeling as well as the loss in parts cut away. The 

 tomatoes should be delivered to the factory promptly, as deterioration begins soon 

 upon standing. 



When the tomatoes are delivered at the factory they are weighed, and inspection 

 should be made of each load. One crate is taken out at random and dumped into a 

 tank of water. All defective fruit can be detected at once, picked out, weighed 

 separately, and the load docked accordingly. Rotten fruit can not be used and 

 green fruit must be held to ripen. The separation at the factory entails extra expense 

 in the inspection and sorting. The rotten fruit should not have been picked and 



