STARCH CROPS 1281 



The writers have investigated the effect of the composition of the water 

 on cooking. They made use of waters the content of sohd matter in which 

 ranged from o to i 225 per 100 000. They observed that the presence of 

 dissolved salts in the water largely affects the time required for cooking, 

 which is longer in the case of salt-charged waters. P\irthermore. the adding 

 of bicarbonate of soda, which is conmionly done in the South of India, 

 reduces the time of cooking. The rapidity of cooking depends therefore 

 on the one hand on the quantity of dissolved salts and on the other hand on 

 the nature of those salts. 



The method which consists in determining the time of cooking is a 

 ver}' primitive one however, which can only give approximate results. 

 The writers adopted a different one based on a measurement of the quantity 

 of starch substance dissolved during cooking. In addition to this weight of 

 starch which passed into solution, they determined the weight of the dry sub- 

 stance of the dholl before and after boiling, as well as that of the nitrogenous 

 substances in the dlinU before and after boiling. The experiments showed that 

 some salts, such as the salts of calcium and magnesium, sodium chloride 

 and hydrochloric acid, sulphates and carbonates reduce the rapidity of 

 cooking, the reduction being apj^roximatel}- proportional to the concentra- 

 tion of the salts. On the other hand, alkaline carbonates and alkalies pro- 

 duce an acceleration. The substances which accelerate cooking most 

 are those which exert a greater solvent action on the albuminoid sub- 

 stances as compared with the starch, which points to the definitive conclu- 

 sion that the rapidity of dissolution of the albuminoids forms the determin- 

 ing factor. 



The writers al.so made it their work to ascertain whether the accelerat- 

 ing agents did not act by saponification of the fatty substances. They found 

 that the fat content of the dholl exercises but very little influence, if any, 

 on the rapidity of cooking. The}' furthermore observed that the practice 

 of treating the gram with red earth and water entails quite a marked de- 

 lay in the rapidity of cooking ; this treatment however is of advantage be- 

 cause it enables the gram to be more easily broken and husked. Finally, 

 they studied the influence of different salts on the liquefaction of starch, 

 utilising rice starch purchased as pure and passed through a 100 mesh sieve ; 

 they found that, among the substances used, only caustic potash increases 

 the quantity of liquefied starch, as compared with pure water ; this quantity 

 is on the bther hand reduced by the other products tried, hydrochloric acid, 

 carbonates of sodium and calcium, sulphates of sodium and magnesium, 

 chlorides of sodium, magnesium and calciimi. 



974 - Comparative Experiments in the Growing of some Varieties of Potato at the 

 Scientific Agricultural Station of Flahult, Sweden. - von feilitzkn jijalmar, in 



S<i)isk(i-Miisskulluilriii)iiiv^t'n lilsknil, W-ayXXX, Xd. ::, pp. iio-i^,"!. Joiikoping, 1916. 



Experiments in sandy and peaty soils with the following varieties of 

 potatoes : 



lutrly: I,iicya, Midsoniniar, IIavl)inm.r, Juni, Atalaiita, Admiral, Niouwc Muizcn ; I'liirly 

 early : Mossios, Svalofs 21 71 and 3101, Gchdnmit Haas, luionu, SvaliJfs .;(>3i; Raflur liilc: C.er 

 tnid, Non plus ultra, The I'aktor, Makalos, Up to date, Hiiganas, I'rcihcrr von Wangi-nheim, 



ST.ARCn CROPS 



