54 



FRUITS AND FRUIT PRODUCTS. 



The actual percentage of solids in these products has but little value 

 in the determination of purity, for it varies within wide limits from 

 a maximum of 82.46 per cent to a minimum of 50.43 per cent, a differ- 

 ence of 32 per cent. The difference, however, between the total sugar 

 and the soluble solids in glucose goods may serve as a valuable indica- 

 tion of the amount of dextrin present, and thus the approximate amount 

 of glucose which has been added, as the amount of sugar-free soluble 

 solids is fairly constant in pure products. 



The percentage of ash is of little value in judging purity, although 

 the glucose products as a rule have a high ash. Many of the pure- 

 fruit products also have a high ash. The relation between the total 

 ash and the alkalinity of the ash, calculated as potassium carbonate 

 (K a CO 3 ), is of marked value in the pure-fruit goods, and differs mate- 

 rially from that of the ash of goods mixed with glucose. The ash of 

 fruits is largely potassium carbonate, as is shown in the following table: 



TABLE 18. Ash of 'fruits. 



'Ibid., 1894, p. 233. 



f F. T. Bioletti, Calif. Expt. Sta. Report, 1894, p. 274. 

 e G. E. Colby, Calif. Expt. Sta. Report, 1890, p. 113. 

 ., 1892, p. 266. 



Tolman, Calif. Expt. Sta. Report, 1900, p. 146. 

 *>G. E. Colby, Calif. Expt. Sta. Report, 1894, p. 266. 

 "Ibid., p. 279. 

 a Ibid., 1896, p. 179. 



It will be seen that there are only small percentages of sulphates and 

 chlorids in the total ash. The chlorid in nearly all is especially low. 

 The banana ash is an exception, being practically all potassium chlorid. 

 In the quantity of substances taken in the ordinary determination of 

 ash of fruit products the sulphates and chlorids in products containing 

 no glucose will amount only to traces, except as has been noted in the 

 banana. 



An appreciable addition of glucose, the ash of which is largely 

 composed of sulphates and chlorids, will greatly change the relation 

 between the alkaline carbonates and the sulphates and chlorids. If 

 this table of fruit ashes be compared with that of glucose ashes (Table 5, 

 p. 33) the great difference will be noted. If a still more complete exam- 

 ination of the ash is made a more striking difference might be shown in 

 the proportion of the different bases. The bases in fruit ash are very 

 largely potash with only small amounts of soda and lime, while in the 

 glucose ash soda and lime are greatly in excess and only traces of pot- 



