VEGETABLE AND FRUIT DEHYDRATION 



205 



percent moisture content did not discolor in 700 days at 35° F., dis- 

 colored slowly at 75° and browned rapidly at 105°. 



The color and texture of rehydrated potatoes are influenced by the 

 variety, growing environment, maturity, prec'irying storage, predrying 

 preparation procedures, time and method of blanching, drying condi- 

 tions, and methods of rehydration. Under-blanched dehydrated 

 potatoes will rehydrate slowly and incompletely. If over-blanched, 

 the pieces may disintegrate in part or entirely when rehydrated at 

 boiling temperatures. The most unsatisfactory samples are those that 

 partially disintegrate, forming a mush in the water while the centers 

 of the pieces remain dry, hard, and chewy. It is assumed that cubes, 

 strips, and slices are produced because the forms are desired for specific 

 table preparations; the rehydration procedure should therefore pre- 

 serve these forms. Samples of high quality will be rehydrated suc- 

 cessfully by boiling without previous soaking, but since table prepara- 

 tions, such as fried, escalloped', and hashed browned potatoes, are best 

 when unboiled potatoes are used, the rate and completeness of rehydra- 

 tion at room temperature, as well as at the boiling point, should be 

 determined. 



Because of the great number of factors that affect quality, some of 

 which can be overcome by changing the conditions of rehydration, it 

 is recommended that each producer conduct a series of tests for rehy- 

 dration and quality on each lot of potatoes. An acceptable product 

 should be rehydrated to satisfactorily plump pieces without becoming 

 mushy or watery. The rehydration ratio (the rehydrated weight di- 

 vided by the dry weight) will vary with the size and shape of the piece, 

 the time held in water, and the temperature of the water. Rehydra- 

 tion ratios obtained with high-quality samples are given in table 27. 



Table 27. — Rehydration ratios obtained with high-quality samples of dehydrated 



potatoes 





Size 



Boiled without soaking 



Boiled after soaking 



overnight 



Soaked 

 over- 



Form 



5 min- 

 utes 



10 min- 

 utes 



20 min- 

 utes 



5 min- 

 utes 



10 min- 

 utes 



20 min- 

 utes 



night, 



not 

 boiled 



Cubes 



Slices, ... . 



Inch 



6 A 6 

 2-1 6 

 5 A2 



2-3 



3-4 



3-4 

 4-5 



3-4 



3-4 



4-5 



2-3 



Strips ... .. 



3-4 



4-5 



4-5 



4-5 





3-4 









In rehydrating dried cut potatoes, acid 8 parts of water to 1 

 part by weight of the product and boil separate samples gently for 

 5, 10, and 20 minutes. Drain carefully through an 8-mesh strainer 

 for 2 minutes. The rehydrated weight should be approximately two 

 to four times the original weight for diced or cubed, and three to five 

 times for julienne strips. Soaking before boiling will give a plumper 

 product and slightly greater drained weight in the larger pieces. 

 Long boiling will cause deterioration in taste, flavor, and color. The 

 rehydrated product should be free from sour or bitter taste, mild in 

 potato flavor, and soft and tender in texture. The color should be 

 uniformly yellowish white to pale yellow. The pieces should be whole 

 and nearly perfect in form. 



