VEGETABLE AND FRUIT DEHYDRATION 197 



CHARD 



Swiss chard is a type of beet that has been developed for its tops 

 rather than its roots and resembles beets in cultivation and distribu- 

 tion. Chard should be handled like other greens. The whole leaves 

 should be cooled, preferably with crushed ice, and stored at low 

 temperature (34° to 35° F.) and high relative humidity (90 to 95 

 percent) . A very short storage or holding period is advisable. 



In the packing plant the material should be sorted and washed. 

 All damaged and discolored leaves should be removed and the stems 

 cut off. Trimming and sorting losses are usually about 50 percent. 

 Blanching should continue until the catalase system is inactivated 

 (table 21). Uniformity of loading in the blancher is important. If 

 delay occurs following blanching, the product should be cooled imme- 

 diately to approximately 65° to 70° F. by cold-water spray or im- 

 mersion. As is true of other greens, the leaves are preferably dried 

 whole. Information on approximate moisture content can be found 

 in table 22 and on suggested drying conditions in tables 23 to 25. 



Dried greens should be carefully packaged in order to minimize 

 breakage of the brittle product. In rehydrating it is recommended 

 that one part by weight of dried chard be added to six parts of water, 

 soaked for 2 hours, and boiled gently for 5 minutes. At the end of 

 the period of boiling the product should be drained by means of an 

 8-mesh strainer and weighed. The weight of rehydrated product 

 should be approximately three to four times the weight of the orig- 

 inal dried product. In quality the rehydrated chard should resemble 

 cooked fresh chard. It should have a pleasant flavor and should be 

 free from unattractive odor. 



SWEET CORN 



The principal regions where sweet corn is produced commercially 

 are the Great Lakes States, the Middle Atlantic States, and the New 

 England States. It is one of the major canning crops ; of the 1.4 million 

 tons produced commercially in 1942, more than 90 percent was grown 

 for processing. 



Eighty percent or more of the sweet corn used for canning and freez- 

 ing is of the hybrid varieties, most of it yellow. In total volume the 

 white hybrids are small, but in certain districts, notably Maryland and 

 Ohio, they are important. Of the open-pollinated varieties, a few 

 have good quality and are adapted to widely separated regions. Stage 

 of maturity is important, the best stage being that which an experi- 

 enced canner would select for canning in whole-grain style. 



Sweet corn loses sweetness rapidly after harvest, but if it is cooled 

 quickly the rapidity of the change can be reduced. Submerging the 

 corn in tanks of ice water or passing it through a vegetable cooler 

 flooded with ice water is an excellent cooling treatment. Corn should 

 not be handled in bulk because of its tenderency to heat, but should be 

 put in baskets, small bags, or crates, and stacked so as to permit air 

 circulation. The best conditions for holding the corn while awaiting 

 processing are a temperature of 31° to 32° F. and a relative humidity 

 of 85 to 90 percent. Deterioration takes place so rapidly that sweet 

 corn should not be held longer than is absolutely necessary, and cer- 

 tainly not more than a few hours. 



