May 3, 1924 
Relative Merits of Sweet Corn Varieties for Canning 439 
to affect profoundly the consistency of the canned product. The sweet varie¬ 
ties contain a high percentage of water-soluble polysaccharides which appear 
to consist of dextrin-like substances mixed with varying amounts of material 
similar to soluble starch. In field corns these water-soluble polysaccharides 
were present in but small quantities and that principally in the form of soluble 
starch. When canned at comparable stages of maturity the kernels of the field 
corn were harder and tougher than any of the sweet varieties. This striking 
difference in cooking quality seems to be due partly to the difference in the 
nature of the polysaccharides. 
7. (a) The so-called “thumb-nail test” proved to be unsatisfactory in the 
selection of corn for canning. It did indicate the rate of maturity and the 
moisture content, but it was not a safe guide in estimating the sugar content, 
especially when applied to different varieties. 
( b ) If the “thumb-nail test” were used to determine the best stage for 
canning, Golden Bantam and other rapidly maturing varieties would probably 
yield a better canned product than StowelFs Evergreen and others of the slowly 
maturing sort. 
8. (a) Observations of three seasons lead to the conclusion that StowelFs 
Evergreen and allied strains do remain green and succulent for a longer time 
than Golden Bantam and some of the earlier corns. The “evergreen” property, 
however, may lead to the canning of an inferior product, as there is a tendency 
-to delay the canning of these varieties longer than the early sorts. From the ’ 
analytical results of one season it seems that the sugar content decreases almost 
as rapidly in the slow maturing as in the rapidly maturing varieties. This must 
be taken into account when considering the merits of the slow-maturing types. 
9. (a) The different varieties of sweet and field corn were also subjected to 
comparative canning tests to determine their relative merits for canning purposes 
and to find at what stage of maturity they were in best canning condition. 
Canned samples were prepared at intervals of 15, 20, 25, and 30 days from 
the date of silking, and complete series of samples from these tests subjected 
to the critical examination of judges qualified by training and experience to 
pass upon their relative merits. Their findings are embodied in the conclusions 
here presented: 
The 15-day samples were very sweet and tender; but were thin, watery, and 
lacking in flavor. However, the rapidly maturing varieties, such as Golden 
Bantam and Crosby, were only slightly too immature to be graded highest in 
quality. 
The 20-day stage samples were still quite tender and sweet and of good flavor, 
but little variation was noted among the varieties in this respect. All exhibited 
a more desirable consistency than at 15 days, but Golden Bantam, Crosby, 
and others that mature rapidly gave a product of a little heavier consistency 
than did the slow-maturing types, such as StowelFs Evergreen. 
At the 25-day stage the corns were tougher, less sweet, and the flavor less 
pleasing than at the 20-day stage. The rapidly maturing varieties yielded 
products of too heavy a consistency to grade as first quality, but the slowly 
maturing types were thinner and about the same as of the early maturing varie¬ 
ties at the 20-day stage. 
At the 30-day stage all varieties were too mature for canning, the product in 
all cases being dry, tough, and very poor in flavor. 
In spite of the above-mentioned differences in varieties they were very nearly the 
same in their general quality. Differences were found to be too slight to be sig¬ 
nificant, it being found practically impossible to identify varieties by quality 
alone. When canned at the same age, especially at 20 days, it was very difficult 
to decide which variety should be given first place, and judges differed widely in 
their choice. 
