SOLANACEjE 



581 



In addition to starch, potatoes contain noticeable amoiints 

 of sugar. The average quantity is not far from 0.35 per 

 cent. This sugar is lost in starch-making, but is utilized 

 in the manufacture of alcohol. 



"Mealiness." — In estimating cooking quaUty of potatoes, 

 meahness is the most important consideration. Mealiness 

 depends quite largely upon the amount of starch in the cells. 

 When boiled in water, the starch grains expand and coalesce. 

 If there is sufficient starch, as is usually the case in the cortex, 

 this expansion ruptures the cell walls, freeing their contents 

 and producing mealiness. A deficiency of starch, as is 

 usually the case in the cells of the internal medulla, produces 

 swelling insufficient to rupture the cell walls; hence, soggi- 

 ness results. 



As has been shown, the different zones of the potato vary 

 considerably in starch content, the cortex being highest, 

 and the internal medulla lowest. If the internal medulla 

 is large and has branches extending into the external me- 

 dulla, the tuber is likely to be hard and soggy when boiled, 

 and to contain zones or parts which will not mash uniformly 

 and readily. The external medulla is usually well stocked 

 with starch. When this is the case, and when the starch is 

 distributed uniformly, leaving no "water areas," a high 

 degree of mealiness can be expected in the boiled tubers, a 

 condition necessary for high table quality in America. 



Quality of Potatoes. — The standards for table quality in 

 potatoes vary somewhat in different countries. The more 

 noticeable differences seem to be between France and the 

 United States. East notes that most of the potatoes which 

 he examined, imported from France, had a yellow flesh, a 

 strong flavor, and were firm and soggy after boiling. In 

 France, potatoes are commonly cooked by frying in deep fat. 

 For this purpose, a potato yellowish in color which holds its 



