The adulteration of mustard is very extensively practised. Of 18 samples bought at random in the shops and tested for the New York State Board of Health, 12 were found to be impure; of 88 samples, examined in the year 1884 by the Massachusetts State Board, 20 were compounds (labelled as such, but in a manner designed to deceive the purchaser). 37 were adulterated with flour, turmeric, and, in some cases, with cayenne, and 31 were found to be pure; in 1885, 211 samples were tested, of which 124 were sophisticated; of 27 samples tested by the National Board of Health, 21 contained foreign admixtures, consisting chiefly of wheat or flour and turmeric, but also including corn-starch, rice, cayenne, and plaster of Paris.

PEPPER.

Black Pepper is the dried unripe berry of Piper nigrum; white pepper, which is much less in use, being the same fruit deprived of its outer skin by maceration in water and friction. The more important constituents of pepper are an alkaloid (piperin), the volatile oil, and the resin, and upon these ingredients its value as a condiment depends. The partial composition of genuine pepper, as given by Blyth, is shown below:—

Variety.Moisture.Piperin.Resin.Aqueous
Extract.		Ash.
Soluble.Total.
per cent.per cent.per cent.per cent.per cent.per cent.
Penang9·535·572·0818·332·214·18
Tellicherry12·904·671·7016·503·385·77
Sumatra10·104·701·7417·592·624·31
Malabar10·544·631·7420·373·455·19

The percentages of piperin, resin, extract, and ash are calculated on the sample dried at 100°. König’s analysis of pepper is as follows:—

Per cent.
Water17·01
Nitrogenous substances11·99
Volatile oil1·12
Fat8·82
Other non-nitrogenous substances42·02
Cellulose14·49
Ash4·57 to 5·00

Heisch[141] has analysed several varieties of pure and commercial pepper, with the following results:—

Water.Total
Ash.		Ash
Soluble
in
Water.		Ash
Soluble
in
Acid.		Ash
Insoluble.		Alkalinity
as K2O.		Starch.Alcoholic
Extract.		Piperin.
per
cent.		per
cent.		per
cent.		per
cent.		per
cent.		per
cent.		per
cent.		per
cent.		per cent.
Black berry9·22
to
14·36		4·35
to
8·99		1·54
to
3·34		1·51
to
3·83		0·36
to
4·38		0·72
to
1·57		48·53
to
56·67		10·47
to
16·20		4·05
to
9·38
White berry13·67
to
17·32		1·28
to
8·78		0·217
to
0·618		0·84
to
2·80		0·22
to
0·69		0·
to
0·22		76·27
to
77·68		9·23
to
9·73		5·13
to
6·14
Fine ground (white)13·901·580·160·900·520·075·3110·664·51
Long pepper12·1513·482·285·525·680·5358·788·291·71
Adulterated ground11·1214·702·024·078·610·7835·8511·572·02