CONTENTS. 



Page. 



Chemical examination of fruits and fruit products 9 



Methods of analysis 9 



General discussion 9 



Preliminary examination 9 



Preparation of samples 10 



Fresh fruits 10 



Juices and jellies 10 



Jams, marmalades, preserves, and canned fruits 11 



Determination of total solids 11 



In juices and jellies 12 



By direct determination 12 



By calculation from specific gravity 12 



In fresh fruits, jams, marmalades, preserves, and canned fruits . . 12 



Determination of insoluble solids 13 



Kremla's method 13 



German official method 13 



Determination of ash 13 



Examination of ash 14 



Alkalinity 1-4 



Sulphates and chlorids 14 



Determination of total acids 14 



Determination of volatile acids 15 



Determination of free mineral acids 15 



Determination of tartaric, citric, and malic acids 16 



Determination of tartaric acid 16 



Determination of citric acid 17 



Determination of nitrogen 17 



Determination of alcohol 17 



Polarization 18 



Determination of cane sugar 18 



By calculation from Clerget's fornmla 18 



By copper reduction 19 



Determination of reducing sugars 19 



Determination of dextrin 20 



Determination of alcohol precipitate 21 



Determination of tannin and coloring matter 22 



Detection of preservatives 22 



Salicylic acid 22 



Benzoic acid 23 



Saccharin 23 



Detection of foreign coloring matter 23 



Detection of coal-tar colors by dyeing wool 24 



Method of Sostegni and Carpentieri 24 



Arata's method 24 



5 



