Xm. FRUITS AND FRUIT PRODUCTS. 



1 PREPARATION OF SAMPLE— TENTATIVE. 



All samples received in open packages (i.e., not in sterile condition) must be trans- 

 ferred without delay to glass-stoppered containers and kept in a cool place. The 

 determination of alcohol, total and volatile acids, solids and sugars, particularly 

 in the case of fruit juices and fresh fruits, should be made at once as fermentation 

 is liable to begin very soon. Portions for the determinations of sucrose and reducing 

 sugar may be weighed and, after adding a slight excess of neutral lead acetate solu- 

 tion, kept without fermenting for several days if desired. The various products 

 are prepared as directed below. 



(a) Juices. — Prepare the fresh juice by pressing the well pulped fruit in a jelly 

 bag and filtering through muslin. 



(b) Jellies and sirups. — Mix thoroughly to insure uniformity in sampling. Weigh 

 60 grams into a 300 cc. flask, add water, dissolve by frequent shaking, then make up 

 to the mark with water, and use aliquots for the various determinations. If the 

 jelly contains starch or other insoluble material, mix thoroughly before taking the 

 aliquots. 



(C) Fresh and dried fruits. — Pulp the whole, well cleaned fruit in a large mortar or 

 by means of a food chopper and mix thoroughly. In the case of stone fruits, remove 

 the pits and determine their proportion in a weighed sample. 



(d) Jams, marmalades, preserves and canned fruits. — Pulp thoroughly the entire 

 contents of the jar or can, as directed under (C); with stone fruits remove the pits 

 and, if desired, determine their proportion in a weighed sample. In the exami- 

 nation of canned fruits it is often sufficient merely to examine the sirups in which the 

 fruits are preserved. In such cases the liquor may be separated and treated as pre- 

 scribed for juices. 



2 ALCOHOL.-TENTATIVE. 



Determine alcohol in 50 grams of the original material as directed under IX, 31 . 



3 TOTAL SOLIDS.— TENTATIVE. 



(a) Juices, jellies and sirups containing no insoluble matter. — Proceed as di- 

 rected in IX, 3, 5, 7 or 10, employing the sample prepared as directed in 1 (a) or (b). 



(b) Fresh and dried fruits, jams, marmalades, preserves, canned foods and other 

 products containing insoluble matter. — Weigh about 20 grams of pulped fresh fruit, 

 or such an amount of fruit products as will give not more than 3-4 grams of dried 

 material; if necessary to secure a thin layer of the material, add a few cc. of water, 

 mix thoroughly, and dry as directed in DC, 3 or 4. 



It is to be noted that certain State and Federal regulations require the moisture 

 in dried apples to be determined by drying for 4 hours at the temperature of boiling 

 water. 



INSOLUBLE SOLIDS. 



4 Direct Method.— Tentative. 



Transfer 50 grams of the sample to a mortar by means of warm water and macerate 

 thoroughly; then transfer to a muslin filter and wash thoroughly with about 500 cc. 

 of warm water, stirring the pulp thoroughly on each addition of water. This amount 

 of water is usually sufficient to remove all soluble material. In extreme cases increase 



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