| Moisture, | 9.32 with variations |
| Fat, | 25.56 |
| Cellulose, | 10.52 |
| Sulphur, | 0.99 |
| Nitrogen, | 4.54 |
| Albuminoids, | 28.37 |
| Myrosin Albumin, | 5.24 |
| Soluble Matter, | 27.38 |
| Volatile Oil, | 0.006 |
| Ash, | 4.57 |
| Soluble, | 0.55 |
Chemical composition of brown mustard seed:
| Moisture, | 8.52 |
| Fat, | 25.54 |
| Cellulose, | 9.01 |
| Albuminoids, | 25.50 |
| Myrosin and Albumin, | 5.24 |
| Soluble Matter, | 24.22 |
| Nitrogen, | 4.38 |
| Sulphur, | 1.28 |
| Ash, | 4.98 |
| Fixed Oil, | 36.00 |
| Volatile Oil, | 0.473 |
| Potassium Myronate, | 1.692 |
| Soluble, | 1.11 with some variations |
Mustard is, no doubt, adulterated more than any other of the condiments, unless it be black pepper. Tumeric is the great agent used to bring out the desired color in the adulteration, and Cayenne pepper is used to give it a tonic flavor. In fact, tumeric has been so extensively used in adulterating the mustard flour that many consumers have become so accustomed to it that, in judging the prepared mustard meal with the eye, they prefer it on account of its yellow color to the genuine mustard. It is claimed by some that tumeric is desirable in toning down the pungency of mustard and in adding to its keeping quality, but if it was too pungent more yellow seed might be used in place of an admixture. Tumeric is treated more as a constituent of the mustard than as a foreign substance—a fact which makes it appear almost a commercial necessity. This should not be allowed.
The natural color of a pure meal is grayish or ashen, more like that of corn meal, and accordingly corn meal is considered a very good article to use as an adulterant; turnip, radish, and rape seed, and broken crackers are also often used. They are mixed with mustard seed and milled with it to increase the bulk and obtain more value from the cake.
Tumeric, whose coloring matter is called curcumin, is a root containing starch. It resembles ginger and is ground in the same way as ginger. It is more generally used in preference to ocher or yellow earth. As mustard flour does not contain any starch, the fraudulent tumeric and starch are readily detected in the farina by the use of iodine and ammonia. Place a little of the suspected sample, which has been previously heated and afterwards allowed to cool, on a piece of glass and add the ammonia or iodine, when the brown coloring principle of the tumeric will be brought out. It may also be detected by its action with borax or boric acid and Martin yellow (dinitronapthol) by the use of 95 per cent. of alcohol. If capsicum be present the test would best be observed by treating the dry mustard with strong alcohol by percolation, which would develop the peculiar pungency of the capsicum when concentrated. The microscope is the best aid to detect it. Wheat flour, if used to adulterate, contains but 1.2 to 2.1 per cent., and reduces the natural yellow color of mustard, which must then be toned up with tumeric or some other coloring matter.
In the discussion of the analysis of mustard seed we may add that the flour is fairly constant in its composition; water is present in small amounts, varying between 3 and 7 per cent.; ash varies between 4 and 6 per cent., and so foreign mineral matter is easily detected. Volatile oil is present in the seed in small amounts, varying from 2.06 in one to as little as 0.55 in another. Fixed oil is one of the most prominent constituents of the seed. It varies in amount from 31 to 37 per cent. Starch is entirely absent in the whole seed. Crude fiber varies, depending on the care and method of milling. The amount should not be more than 6 to 7 per cent. Albuminoids make up a large part of the seed, varying from 25 to 30 per cent. If they are below 20 per cent. this fact points to dilution with material poor in nitrogen. The undetermined matter consists of gum and some unidentified substances soluble in alcohol, whose estimation is of no particular value, as a means of detecting adulterations.
As a whole, for general reference, the following table may be used:
| Water, | 3 to 7 per cent. |
| Ash, | 4 to 6 per cent. |
| Volatile Oil, | ½ to 2 per cent. |
| Fixed Oil, | 31 to 37 per cent., from entire seed |
| Fixed Oil, | 16 to 18 per cent., from cake |
| Starch, | None |
| Crude Fiber, | 5 to 18 per cent. |
| Albuminoids, | 25 to 32 per cent. |