Table 3. — Sugar added to cooked fruits 



Fruit and preparation form 



Market form 



Market unit 



Sugar added 



Cherries, red sour, cooked.. 



Canned, water pack 



Fresh -- 



No. 303 can 



1-lb. package 



1-lb. bulk 



Cup 



0.3 



Cranberry sauce, whole or strained 



2. 



Plums, cooked whole or halves, unpeeled_ 



do 



. 7 





|Fresh. _ 



1-lb. bulk 



.3 



Rhubarb 



IFrozen, _ 



1-lb . package 







. 3 









readily analyzed for ascorbic acid by the photo- 

 metric xylene extraction method of Robinson 

 and Stotz (W). 



Dehydroascorbic acid plus diketogulonic acid. — 

 Determination of these products was made by a 

 modification of the procedure of Roe (21, 22) 

 using 2,4-dinitrophenylhydrazine. 



Titratable acidity. — Titratable acidity was deter- 

 mined on solids and juices of all fruits except 

 orange juice. Solids were blended with water; 

 liquids were diluted with water. Both were 

 diluted to volimie and aliquots titrated to pH 8 

 with O.lN NaOH, as described by Guadagni 

 and others (8). 



Reflected color. — Gardner Color-Difference Meter 

 (7) readings were taken, using the "L" scale in 

 which L expresses visual lightness; a/,, redness or 

 greenness; and fez,, yellowness or blueness. Five 

 readings were taken ; between readings the sample 

 was turned about 72°. The average of the five 

 measurements was considered the color value of 

 the sample. The color standards used for the 

 fruits tested are shown in table 4. 



Shear force. — An L.E.E. Kramer Shear Press 

 (12) with a standard cell and a 1,000-pound proving 

 ring was used for all fruits tested except pine- 

 apple, which required a 3,000-pound proving 



Soluble solids. — Determinations of soluble solids 

 were made with a Bausch & Lomb Abbe — 3-L 

 Refractometer (1). 



Cloud. — Cloud determinations were made on 

 orange juice reconstituted to 5° Baume. Both 

 the thawing index (TI) and the sensitivity index 



Table 4. — Color standards for fruits tested 



Fruit 



L 



(visual 

 lightness) 



at 



(redness 



or 



greenness) 



6t 

 (yellow- 

 ness or 

 blueness) 



Orange juice 



Strawberries, rasp- 

 berries 



Peaches 



Grapefruit, pineapple _ 



74. 6 



24. 6 

 51. 8 



78. 2 



+ 2. 7 



+ 18.3 

 -3. 4 

 -1. 7 



+ 50. 5 



+ 5.6 

 + 30.2 

 + 22. 6 



(SI) were determined by the procedure of 

 McCoUoch and Rice (15). 



Panel evaluation. — Color, flavor, and texture of 

 the fresh, canned, and frozen fruits were rated by 

 a trained panel of five members. Consistency of 

 juice was also rated for peaches, raspberries, and 

 strawberries. Coded samples were presented to 

 the panel for quality ratings and for detection of 

 any off-flavor. 



The fresh and canned fruits were rated as fol- 

 lows: Color ranged from 5, very good, to 1, very 

 poor; texture ranged from 5, characteristic, to 1, 

 very poor; flavor ranged from 5, very desirable, to 

 1, very undesirable. The rating scales for each 

 quality characteristic of the various frozen fruits 

 are given in table 5. Scores given in the text refer 

 to mean values for all members of the panel. 



Evaluation of data. — Mean values, ranges, and 

 coefficients of variation were calculated on data 

 for all quality characteristics of the frozen fruit 

 samples investigated. 



758-874 O - 65 - 2 



