282 SCIENTIFIC AND APPLIED PHARMACOGNOSY 



Brassica nigra (black mustard) and Brassica juncea yield 0.6 

 per cent of volatile mustard oil (calculated as allylisothiocyanate 

 and determined by the method given in Service and Regulatory 

 Announcements, Chemistry 20). The varieties and species closely 

 related to the types of Brassica nigra and Brassica juncea yield not 

 less than 0.6 per cent of volatile mustard oil, similar in character 

 and composition to the volatile oils yielded by Brassica nigra and 

 Brassica juncea. These mustard seeds contain not more than 5 

 per cent of total ash, nor more than 1.5 per cent of ash insoluble in 

 hydrochloric acid. 



Ground mustard is the powder made from mustard seed, and con- 

 forms to the standards for mustard seed. 



Mustard flour is the powder made from mustard seed with the 

 hulls largely removed and with or without the removal of a portion 

 of the fixed oil. It contains not more than 1.5 per cent of starch, 

 nor more than 6 per cent of total ash. 



Prepared mustard, German mustard, French mustard, mustard 

 paste, is a paste composed of a mixture of ground mustard or mus- 

 tard flour, with salt, a vinegar, and with or without spices or other 

 condiments which do not simulate the color of yellow ground mus- 

 tard. Calculated free from water, fat, and salt, it contains not more 

 than 24 per cent of carbohydrates (calculated as starch), not more 

 than 12 per cent of crude fiber, nor less than 5.6 per cent of nitrogen 

 derived solely from the materials herein named. (U. S. Dept. 

 Agric.). 



Adulterants. While the whole mustard is seldom, if ever, adul- 

 terated, ground mustard may contain wheat middlings or shorts, 

 and occasionally rice or pea flour; when these flours are employed, 

 turmeric is also added to bring up the color, which is readily detected 

 by means of the microscope (Fig. 88) and by its becoming deep red 

 with sulphuric acid and blue with iodin. Prepared mustard is some- 

 times adulterated with white mustard hulls separated from the seed 

 before expression of the fixed oil. 



Allied Plants. In Indian Colza (Brassica campestris Sarson) 

 the epidermis forms a homogenous layer, a sub-epidermal layer not 

 being present. The seeds of Turnip (Brassica campestris) are sup- 

 posed to be the white mustard of Sanscrit writers. 



Ground White Mustard or white mustard flour is prepared 

 from the seed of Brassica alba with or without the removal of a part 

 of the seed-coat (hulls) and the fixed oil. In fact, not infrequently 

 mustard seed-cake is employed. 



