COMMERCIAL CANNING OF FOODS. py: 
The cut-out weight of fruit will not be the same as the weight of fruit introduced, 
but will vary according to the structure and state of maturity of the fruit and the 
method of handling. A fruit which is very succulent and has little supporting tissue, 
such as strawberries or raspberries, undergoes heavy shrinkage, depending upon the 
strength of the sirup used, while a pear, with its stronger supporting tissue, will suffer 
little change. The sugar of the sirup unites with the plant juice, and abstracts a 
part of the water. The fruit loses in weight, the sirup gaining a proportionate amount. 
The changes in weight, however, are not as great as those in volume. The most 
marked decrease in the weight of fruit is apparent shortly after processing, after which 
a gradual increase takes place until the sugar in the fruit and that in the sirup become 
equalized. Just how much time is required for this process has not been determined. 
As an illustration of the changes going on within the can, the analysis of two lots of 
blackberries and the weights of apricots, cherries, peaches, and pears are given. The 
first analysis of the blackberries was made the day after canning, the second 70 days 
later. The weights on the other fruits were taken for the first reading within 30 days 
aiter packing and for the second from 120 to 180 days later. The cans were not selected 
to have a definite and uniform weight, so that the gross weight varies somewhat, but 
the change in each case goes on in one direction, as is shown in the table. The average 
given is for seven samples in each set. 
The effect of standing on changes in composition of blackberries and on the weight of solids 
and sirup of apricots, cherries, peaches, and pears. 
A : Weight | Weight | Weight P . Acidity 
ee ok | of | of | cate, | ieee: | suirose, | (as citric 
8: so". | contents.| fruit. sirup. fs sueay, acid). 
Blackberries, 50° Grams per|Grams per|Grams per 
sirup: Grams. | Grams. | Grams. | Grams. | Degrees. | 100 cc. 100 cc. 100 ce. 
LL eee 1,050 910 384 526 31.6 9. 93 18. 27 0. 42 
OE 5 ee Sees 1,049 909 428 481 29. 1 12. 35 13. 71 . 56 
_ Apricots, standard: 
First reading. .... 992 852 465 387 DSS GH Vetere te eet aS ae cies fos Sela ars Ae 
Second reading... 1,010 870 553 307 LN Cf fas a eee on ace chee | aemeciane 
pnts, extra stand- 
ard: 
First reading. .... 1,023 883 465 418 DOS VES ROS SAO: SAE ee ae 
Second reading... 1,013 873 563 337 AOS Orit ie ci ale ewe Uae) | ey aay 
Cherries, standard: 
First reading. .... 1,018 875 545 333 WSs [ess ete celeste || gas ee eee 
Second reading... 1,013 873 570 303 fer On| ein ee pte sie eke i eveeieen ets Mie demes alas 
Cherries, extra stand- 
ard: 
First reading. .... 1,030 890 507 383 ZA OPN Scceyare trate le ian penance pee tie ARN 
Second reading... 1,027 887 542 345 2104) 2%,. 44258 o| teeta Gales 
Peaches, standard: 
First reading. .... 977 837 506 331 aed bes See ee lh CAPE aE ES 
Second reading... 979 839 569 277 aS ea yn) Meee Ue Ae Pene iyare ee eee ee a oe 
a extra stand- 
ard: 
First reading. .... 1,010 870 503 367 225 2p | aeete apo | Sees eyes ce eae 
Second reading... 1,025 885 605 280 2203 NAL SUIES Eee eS Sake 
Pears, extra stand- 
ard: 
First reading. .... 982 842 532 310 NOHO) Eb os noe ts ahead anette Agee yeh 
Second reading... $88 848 565 283 Dive Gpaleserers cid acess enacts tena |e eenteaeeees ON 
Unfortunately, systematic data are not available concerning the rate or extent of 
the changes. Some of the better packers recognize these changes in a practical way 
by refusing to send out samples of fruits sooner than 30 or 40 days after packing, stating 
that at first neither the appearance nor the flavor is what it will be after standing. 
While a heavy sirup tends to soften and shrink ripe fruit, it has less effect on that which 
is slightly underripe or green. The underripe fruit gives sharper, cleaner-cut edges, 
especially with peaches, pears, and apricots, and less color and fewer particles of fruit 
in the sirup. The tendency to exaggerate these points of appearance accounts for the 
use of some material which would be improved in flavor if it were allowed to mature 
