32 



BULLETIN aSe, U. S. DEPAETMEl^I-T OF AGRICULTXJEE. 



whether varietal differences in corn had. any effect upon the rate of 

 change of temperature at the center of the can. Comparison was 

 made of White Dent field corn, Golden Bantam, Country Gentleman, 

 Stowell's Evergreen, and Crosby's Early. No differences of impor- 

 tance were observed when these varieties were prepared in Maine 

 style. Tests with corn at different stages of maturity were not made, 

 although this would have been of interest, since the starch content is 

 known to increase during the approach to maturity. 



It is not probable, however, that the differences in maturity gen- 

 erally permissible in canning practice would have any effect. 



MAINE STYLE AND MARYLAND STYLE COMPARED. 



Having found that differences in the fineness of division of particles 

 affects the rate of change of temperature, tests were made for the 



purpose of compar- 

 ing the Maine style 

 and Maryland style 

 of packing. Sto- 

 well's Evergreen was 

 the variety used for 

 these tests. In the 

 Maine style the corn 

 was prepared as al- 

 ready described. In 

 the Maryland style 



60 





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Fig. 35. — Time-temperature relations for sweet corn 

 (Maine style and Maryland style) processed at 100° C. 

 in No. 2 tin cans. These curves were plotted from 

 temperature readings made at intervals of 5 minutes. 

 Proportion of corn to liquor : A, Maryland style, 2.1 : 1 ; 

 B, Maine style, 2.1 : 1 ; C, Maine style, 3.1 : 1. 



the corn was pre- 

 pared by cutting the 

 grains from the cob 

 as nearly whole as 

 possible, without 

 scraping. No. 2 tin 

 cans were used, and the same proportion of corn and liquor (by 

 weight) was used in each case. The proportion of corn to liquor 

 was 2.1 to 1. The results when processed in the water bath at 100° C. 

 are shown in figure 35. 



A higher rate of change of temperature is noted in the Maryland 

 style than in the Maine style, as the result of the greater freedom of 

 movement of the liquor filling the interspaces. There was some con- 

 vection in each case, but the results probably would- have been entirely 

 different if the proportion of water to corn had been other than that 

 used in these tests. Such marked differences as are shown in these ex- 

 periments should be borne in mind when processing periods are under 

 consideration. 



EFFECT OF DIFFERENT PROPORTIONS OP LIQUOR. 



Tests were made to determine the effect of different proportions of 

 corn to liquor upon the rate at which heat passes into the can. The 



