CeSe ( Swiss cheese) is often found adul terated with foreign fats, potato flour, and cer tain coloring substances. The fraud can be detected by a chemical examination. See CHEEst.:.
Bread is often adulterated, for the purpose of improving its color, with alum or with sulphate of copper. The presence of these substances may be detected by digesting a sample of the bread with water, and leaving a strip of pure gelatin in contact with this for several hours. On dissolving the gelatin in wood alcohol con taining logwood and ammonium carbonate, the presence of alum is shown by the appearance of a blue coloration, The presence of copper sul phate is similarly revealed by the logwood solu tion turning green. The addition of alum may mask the unwholesome qualities of poor bread, and may thus be a source of considerable danger. On the other hand, its normal presence in bak ing-powders is considered by sonic authorities as entirely free from objection beeause, according to them, the alum is during the baking process converted into an insoluble, and hence harmless, aluminum phosphate.
Flour is often adulterated by the addition of cheaper cereals, and the presence of these may he detected microscopically. The addition of gypsum and other mineral matter is practiced much more extensively in the European coun tries than in the United States. The presence of such adulterants may he revealed by determin ing the amount of ash left on burning a known quantity of flour.
Confectionery has been adulterated with a variety of coloring substances, poisonous as well as harmless; with starch, sawdust, artificial "fruit oils," crude benzahlehyde, and a variety of other substances. Within recent years, eyer, the adulteration of confectionery has greatly diminished.
Coffee, when sold in the ground state, is often adulterated with considerable amounts of chic ory, roasted beans or peas, tanbark, sawdust, stove-rust, etc. The presence of adulterants may be detected by chemical analysis, the prin cipal steps of which consist in the determination of the percentage of matter soluble in water, and the determination of sugars before and after treatment with hot mineral acids. The latter
cause a considerable increase of sugar in pure coffee, while they have no effect on the amount of sugar contained in chicory.
Tea is often adulterated with the leaves of linden, sage, strawberry, and other plants. The presence of these may be detected microscopi cally, or else by determining chemically the amount of caffeine, which is hardly ever less than 1% in pure tea. "Spent tea" is often sold. and to make the infusion appear stronger than it really is, iron salts are added to the leaves. See TEA.
Cocoa and chocolate are often found to con tain flour, potato meal, sawdust, mutton tallow, vegetable oils, and a variety of other substances. The presence of adulterants is detected by deter mining the amounts of thedwomine, fat. dextrin, starch. and inorganic matter.
sugar, that is. ordinary white cane sugar, is usually very pure. Glucose, terra alba, sand, and certain other substances are sometimes, though rarely, used as adulterants. On the other hand, brown sugars often contain consid erable al1101Intg of glucose and other adulterants. Pure cane sugar has a dry, white appearance and a pure. sweet taste; when burned it leaves very little ash. It has been held that the pres enee of Vv, of sand in Manila sugar is almost unavoidable. lf, however, it is possible to prove that the percentage of has been intention ally raised by the seller to that amount, the latter is punishable criminally under modern statutes.
Honey is often largely adulterated with syrup, meal, co•n-starch, cane sugar, grape sugar, etc. The fraud can only he detected by chemical analysis.
Jellies and Jams are often adulterated with gelatin, glue, and with more or less injurious coloring substances and artificial "fruit oils." The adulteration can be detected only by a care ful chemical examination. Considerable quan tities of zinc oxide have been found in preserved fruits.