COMMEECIAL CANISTHSTG OF FOODS. 21 



nearly accurate than one which involves pouring the liquid upon a screen. With 

 such products as tomatoes, which are cooked until they are broken to pieces or 

 mushy, the weight of solids will be a little higher than if a screen were used, but 

 for products which are whole or in separate pieces there will be little difference 

 between the two methods. 



The acidity is uniformly expressed in terms calculated as citric acid. The results 

 of the experiments apply only to California products, as in structure and behavior 

 those fruits differ so much fi-om those grown in other sections of the United States 

 that inferences of similar behavior would not be warranted. Practically all the 

 chemical work reported was performed by F. D. Merrill in the San Francisco Food 

 and Drug Inspection Laboratory, and the last analysis by A. W. Broomell in the 

 Bureau of Chemistry. 



DETAILED CONSIDERATION OF THE VARIOUS PRODUCTS. 



FRUITS. 



General Discussion. 



The first essential is that the fruits be harvested when in prime condition, handled 

 with care to prevent injury or bruising, and conveyed with speed from the tree or 

 vine to the factory. For canning purposes it is not necessary, and may not be 

 desirable, that all fruits be as far advanced or as soft as for eating, but they should 

 be ripe, with the flavor characteristic of the ripe fruit. They should not be so far 

 advanced that they will not withstand the ordinary cooking necessary for steriliza- 

 tion without breaking to pieces. The prime condition for canning is that state of 

 maturity in which the flavor and other characteristic qualities have been developed 

 to the maximum and may be retained during sterilization. 



Bruised or damaged fruit can not be made attractive, and its use involves heavy 

 waste. The proper handling of the fruit is therefore very important. Apricots, 

 peaches, pears, etc., should be handled in shallow boxes which will not hold more 

 than a bushel and will not admit of more than three or four layers of fruit. The 

 t^)p should be protected with cleats, so that one box can be set upon another without 

 tijuching the fruit, thus insuring some ventilation. The small fruits — strawberries, 

 raspberries, blackberries, and loganberries — are handled almost exclusively in 

 chests, which are illu.strated in detail in Plate II. The California packers have 

 develope<i this part of the business to a higher degree of perfection than those in 

 any other section of the country. The conical basket used in handling tomatoes in 

 the East should be abolished. The depth is too great and the shape such that the 

 weight of superimposed fruit wedges the lower layers tightly together, causing 

 cru.shing, rotting, and excessive waste. The baskets are weak, do not stack without 

 bnii.''ing or cutting the fruit, and easily become disarranged or broken in shipping. 



Rapid transfer of the fruit to the fact<^}ry after it has been picked is very essential. 

 Deterioration in flavor and weight begins early; conditions favor the growth of 

 organi.sms, and bax-teria, ycuft, and mold may develoj) wherever the fruits press 

 together or the skins are broken. Delicate fruits, such as l)erri(!S, if picked in the 

 morning should be at the factory in the afternoon, or if jiickcsd in the evening should 

 be delivered in the morning. Fruits with hard skins will last much hjiiger, but the 

 rule with all should be quick action. One of the disadvantages <;f a fact(jry located in 

 a city is the <lelay in refoiving fruit jimmptly; dejjendence upon th(» surplus of the 

 fresh fruit market is hazardous. 



Oua Houne of trouble and a causrj of si)oilage of much fruit is contamination from 

 Wiur arul rm.Uly boxes. VVhe-n a box is used s(!V(!ral tinios it b(!(oni(;H pcrnuinentiy 

 inf«'<l(!<l and a cause of infection by spoliage organisms. This can be conlroilcd 

 without much difliculty by having a tight room in which the worst boxes are plac»;d 



