190 



FOODS AND FOOD ADULTERANTS. 



The process for the estimation of pipeline approved by Blyth is ex- 

 traction with petroleum ether and treatment of the extract with sodic 

 hydrate to remove the resin. Subsequent investigations by Lenz con- 

 demn this method, however. 



More recently Eottger * has investigated the pepper-corn with especial 

 consideration of the question of detection of adulteration, and decided 

 that the examination of commercial peppers should be directed to de- 

 terminations of the inorganic constituents, the percentage of water, and 

 the microscope, with determinations of the soluble and insoluble ash 

 and piperine in certain instances. He decides that the alcohol and 

 ether extracts are of no value, quoting great variations in his results 

 and those of others. He found 



Borgman, Wolff, and Biechelet likewise have determined the amount 

 of alcohol extract, but have neglected the ether extract. It seems diffi- 

 cult to understand why the alcohol extract should be selected, as the 

 ether is much simpler, and refers almost directly to the amount of vola- 

 tile oil and piperine which the spice contains, without so much of the 

 indefinite resin and sugar which the alcohol extracts. The determina- 

 tion of water was made as follows by Eottger : The powdered pepper 

 was placed for three hours over sulphuric acid, and a portion then 

 weighed out and dried at 100 C. for one and a half hours, then for a quar- 

 ter of an hour at a time until it begins to gain weight. He found the 

 variations to be between 12.6 and 14.7 for black pepper, and 12.9 and 

 and 14.5 for white pepper. 



This striking agreement, he considers, makes this determination of 

 value. It is open to serious criticism and is of little value, in our view, 

 for the following reason: By consulting our investigations on the hy- 

 groscopic character of organic matter in a state of fine division,! it will 

 be seen that allowing peppers to remain over sulphuric acid for three 

 hours would not accomplish the end desired, at least in our climate, viz, 

 reducing the moisture in all to a constant figure, and in addition Eottger 

 takes no account of the volatile oil lost at 100. In our analyses we find, 

 in fact, much less water than he does, as is usual in all organic material 

 in our drier climate, and no greater variation among the peppers than 

 the adulterated specimens. Practical tests of the method also proved 

 unsatisfactory. 



* Ber. uber d. 4 Ver. Bayrisch. Vertreter der angew Cheraie, 97-102. 



tVide Bibliography. 



+ Bull. No. 4, Div. of Chem., Department of Agriculture. 



