. Cyclopedia of farm crops. Farm produce; Agriculture. Fig. 252. Peach peelers for canning factory. water, starch and the like, variations of fifty to seventy-five minutes being found in different fac- tories. Sweet corn undergoes fermentative changes even more rapidly than do peas, because of its high percentage of sugar, and especially from the fact that the kernels are broken, thus allowing direct access of bacteria to the saccharine juices. Unless means were taken to prevent it, fermentation would take place in a short. time. An extended study of this fermentation has been made by W. L. Un
. Cyclopedia of farm crops. Farm produce; Agriculture. Fig. 252. Peach peelers for canning factory. water, starch and the like, variations of fifty to seventy-five minutes being found in different fac- tories. Sweet corn undergoes fermentative changes even more rapidly than do peas, because of its high percentage of sugar, and especially from the fact that the kernels are broken, thus allowing direct access of bacteria to the saccharine juices. Unless means were taken to prevent it, fermentation would take place in a short. time. An extended study of this fermentation has been made by W. L. Underwood and the writer. Several species of bacteria were discovered in cans of "sour" corn, some of these being able to resist five hours" boiling without being destroyed. Further investi- gation showed the source of these germs to be. the ears of corn. Bacteriological examination of healthy ears of fresh corn revealed the presence of germs on the kernels beneath the husks. These bacteria give characteristic reactions with nutrient media, and produce rapid fermentation of sugars, giving rise mainly to lactic acid, but also to forms of butyric and acetic acid. Sterilized sweet corn was converted in a few hours to a mass with strong acid reaction and sour taste. The most favorable temperature is 36° to 40° C. The effect of the various steps in the canning process was also investigated. In the "cooker" many bacteria are destroyed, the more resistant ones, however, remaining uninjured. Two-pound cans which were given a heating' at 120° C. (248° F.) for thirty minutes were found to contain living bacteria, and cans so treated frequently become much disturbed within a few days. On the other hand, if the heating process is continued for a sufiiciently long time all bacteria are destroyed. The reason for the necessity of the long period of heating is the low conducting power for heat of the corn. Experiments made with maximum regis- tering thermometers show
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