FRUITS AND FRUIT PRODUCTS, 



PART I.— CHEMICAL EXAMINATION OF FRUITS AND FRUIT 



PRODUCTS. 



By L. S. Muxsox and L. M. Tolman. 



METHODS OF ANALYSIS. 

 GENERAL DISCUSSION. 



In making an examination of fruits or fruit products much depends 

 upon the object of the analysis. Hence the preparation of the samples, 

 the portions used for anatysis, and the determinations to be made, 

 nmst be left largely to the judgment of the anal^^st. In the exami- 

 nation of fresh fruits the determinations of pressed pulp and juice, the 

 amount of waste material, and the relation between tiesh and pit are 

 often of considerable value. The examination should be so complete 

 as to leave no doubt regarding the interpretation of the data obtained. 

 It should be borne in mind that the more exhaustive the examination 

 the greater is its scientific value and the broader is the view it gives 

 of the nature of the product. 



PRELIMINARY EXAMINATION. 



Much valuable information may be obtained by a careful inspection 

 of the samples under examination. The general appearance of fresh 

 fruits, their size, color, and taste, are valuable in determining the 

 quality. In the case of jellies and other fruit products preserved in 

 glass this examination is of great importance. The label should be 

 preserved and the general appearance, taste, odor, color, and consist- 

 enc}^ should be carefully noted, as they are valuable indications of the 

 quality of the goods. The capacity of the receptacle should be noted 

 by either measuring its volume or weighing the contents. In jellies 

 containing starch there is a turbidity and often appreciable amounts 

 of insoluble material, while in its absence the solution is perfectly clear. 

 By this inspection low-grade fruits ma}" be detected in jams, and an 

 examination of the seeds may show the presence of foreign fruits. In 

 the case of products put up in tins, any bulging of the can or escape 

 of gas on opening, showing incomplete sterilization, should be care- 



9 



