| Description. | Total Solids. | Acidity. | Reducing Sugar. | Cane Sugar. | Total Sugar. |
|---|---|---|---|---|---|
| Percent. | Percent. | Percent. | Percent. | Percent. | |
| Apricots, | 70.15 | .407 | 38.96 | 26.00 | 64.96 |
| Currants, | 66.32 | 1.117 | 52.45 | 1.64 | 54.09 |
| Figs, | 69.89 | .744 | .... | 45.92 | .... |
| Grape fruit, | 69.20 | .387 | 27.00 | 35.51 | 62.51 |
| Guava, | 82.46 | .299 | 25.14 | 52.73 | 77.87 |
| Peach, | 65.65 | .500 | 36.48 | 23.16 | 59.64 |
| Strawberries, | 75.83 | .480 | 37.15 | 31.43 | 68.58 |
The average composition of a large number of pure jams, some of which were made in the laboratory and some purchased in the open market, is as follows:
| Total Solids. | Acidity. | Reducing Sugar. | Cane Sugar. | Total Sugar. | |
|---|---|---|---|---|---|
| Percent. | Percent. | Percent. | Percent. | Percent. | |
| Average, | 65.98 | .536 | 36.41 | 22.15 | 58.56 |
| Maximum, | 82.46 | 1.355 | 61.02 | 54.23 | .... |
| Minimum, | 50.43 | .163 | 13.20 | .30 | .... |
The analytical data show that the jams, in so far as active food constituents are concerned, are composed chiefly of sugar. These sugars include both that natural to the fruit and that which has been added. The average content of sugar in round numbers is 58.5 percent, while in round numbers the average content of solids, not sugar, is 7.5 percent. It is thus seen that the amount of sugar present in round numbers is eight times as great as that of the other solids. It is also noticed that the percentage of reducing sugar is about one-third greater than the cane sugar, indicating that the inversion of the sugar, when the real fruits have been used in the manufacture, has been carried to such an extent as to avoid any danger of crystallization. These data are all in complete refutation of the claims made by many manufacturers that it is necessary to add glucose in the manufacture of complex products of this kind in order to prevent crystallization. If the real fruit is used in the proper quantity and the manufacture conducted according to the approved method, there is no danger of crystallization except in those rare cases where the fruits used have little or no acid.
Adulteration of Jams.
—The adulterations of jams are practically the same as those which are practiced with jellies. Artificial colors have been very extensively used together with the artificial flavors resembling the fruits, the names of which appear erroneously upon the packages. Glucose is used to a large extent in these adulterated goods. In the adulterated articles a preservative is nearly always present. Starch is used but very rarely for adulterating articles of this kind.
Fifty-eight samples of jams which proved to be adulterated were bought on the open market by the Bureau of Chemistry, none of which bore any label or description indicating that it was an adulterated article. The character of the principal adulterant (glucose) in each case is revealed at once by the polarization, which is always strongly right-handed, and also by other chemical tests for glucose. The quantity of sulfate and chlorid in the ash of these samples is always very considerably increased over that of the natural product. The quantity of glucose in some of the samples is so great as to indicate that practically the whole of the solid matter is composed of this substance. In two samples the alleged jam contained no fruit product whatever. In many cases more than 70 percent of glucose is found and in one instance as high as 76 percent. In a great majority of the cases the glucose is approximately one-half of the whole weight of the jam. In a great many cases the glucose was present in quantities which indicated the utilization of some fruit product. There were a few cases where the amount of glucose fell below 10 percent. Artificial coloring matter was present in almost every case, and in the great majority of cases either benzoic acid or salicylic acid is present as a preservative. The colors used are coal tar dyes and cochineal.
It is evident that articles of food adulterated in this manner should not be permitted to bear the name of the natural product, and in many of the states the local laws forbid the use of a misleading name. The national law, which was approved on the 30th of June, 1906, also forbids misbranding of this description.
In addition to the jams which on their labels bore no indication of the adulterations, a number of samples of jam were purchased labeled “Compound,” or in some way indicating that they were not the pure article. Thirteen samples of this kind were examined in the Bureau of Chemistry and all of them had very large quantities of glucose, the largest amount present in any one case being 37 percent. They were all artificially colored, and ten of them contained preservatives, either benzoic or salicylic acid.