68 BULLETIN 196, U. S. DEPARTMENT OF AGRICULTURE. 
seldom bulge in this way for the reason that they can not be sealed when too full, 
and, as a rule, they weigh from 3 to 4 ounces less than the hand-filled cans. Over- 
filling also necessitates a longer process, breaking up the fruit and detracting from 
the appearance of the product. In order to bring out the flavor some canners add 
one teaspoonful of a mixture of equal parts of salt and sugar, or of one part of salt to 
two parts of sugar, to each can. This is rarely done except upon high-grade goods 
and must be done by hand in order to insure uniformity. 
There are several types of filling machines for solder-topped cans. A type in use 
for some time consists of a chamber to hold a quantity of tomatoes sufficient to fill a 
can, and a plunger or piston to force them in. The result is that the fruit is more or 
less badly broken, though just as good in quality as the handpacked. Some of the 
latest machines fill the cans on the principle of the collapsible tube, resulting in a 
much better appearing product than with the old type. During the last season 
machines were designed to fill the open-top can. All fill by volume rather than by 
weight. When the filling is done by hand the product is often designated “hand- 
packed’’ or “solid-packed,’’ to distinguish it from that filled by machine, or filled 
with tomatoes and juice added to fill the interspaces. The use of water in canning 
tomatoes is unnecessary and constitutes an adulteration. Its only justification has 
been in the packing of whole-peeled or unpeeled fruit for salads, where perfect appear- 
ance rather than food value is the criterion of success. These are packed, one in 
a flat can, or five or six in a single layer in the large flat can, every effort being made 
to retain the fruit whole. The quantity packed is very small and equally good results 
can be obtained by using juice in place of water. The use of about 4 ounces of juice 
in filling the interstices in fancy selected stock materially increases the amount of 
whole fruit on the cut-out and adds somewhat to the appearance. The juice used 
for this purpose should be of the same grade as the stock and not made from trimmings. 
The packing of tomatoes results in two classes of product: (1) That in which only 
whole stock or solid pieces are used; (2) pulp or purée. The two products are dis- 
tinct and both have useful places, but one should not be substituted for the other. 
The term “canned tomato”’ applies to whole or solid fruit and not to the mixture. 
The regular packed tomatoes should be well exhausted, sealed, and processed for 
from 35 to 55 minutes; the more solid the pack, the heavier the process required. 
Thirty-five minutes is not safe with most packers nor when cooling is practiced. 
For fancy tomatoes it is better to exhaust slowly to about 120° F., as there will be 
less breaking down of the fruit than if it be subjected to high heat for a shorter time. 
The length of time given in processing depends upon the condition of the fruit; if 
soft-ripe and closely packed, it will require a longer tim®é than if firm and sound. 
This rule, the reverse of what is generally supposed to be true, applies throughout 
canning. The softer and mushier the consistency, the harder for the heat to pene- 
trate. Some packers process in the retort at 220° to 230° F. for 25 minutes, but this 
has the effect of breaking the fruit. Itis preferable to cool the can, as there will be 
a gain of from 1 to 3 ounces in solids on draining and a better color. 
Somewhat too much stress is being placed upon the quantity of solid meat which 
will be found in a can of tomatoes after draining on ascreen. A very high percentage 
of solid meat may mean the use of a variety which is hard and inferior, or fruit which 
is slightly green, in which event the flavor is deficient. The full rich flavor of the 
tomato is not developed until it is thoroughly ripe, so ripe that the processing will 
~ cause a part of the tissue to break down and after long shipments it may be badly 
broken. While it is desirable to have a large proportion of the fruit whole or in large 
pieces, a broken condition is not necessarily evidence of poor stock cr improper methods. 
The addition of juice or water to cans has a direct effect upon the cut-out, the differ- 
ence being in the quantity and specific gravity of the liquid portion. The effect 
of adding water is shown in the following table: 
