Vol. XVI. No. 3S8. 



THE AGRICULTURAL NEWS. 



71 



VALUE OF RICE AS HUMAN FOOD. 



Much attention has been given at the Research 

 Institute at Pusa, India, to the chemical composition 

 of different kinds of of rice. According to the Report 

 on the Institute for lOl.'S-liJ, the composition of the 

 rices did not vary much, but the analytical figures allow 

 an interesting deduction. The Report states: — 



The amounts of oil, fibre and ash vary between very 

 narrow limits, and the sura of these constituents will be more 

 or less constant. The sum total of the remaining 

 constituents af albuminoids and soluble carbohydrates i^ 

 thus also constant It was found that the sum of the 

 percentage figures for albuminoids and soluble carbohydrates, 

 in all instances except three, fell between 94 and 9-3. In 

 these three latter eases the figures were 93"9 and 95o. But 

 the deviation is so small that the general observation may be 

 said to hold good in these ins-tances also. It was thus noted 

 that when the amount of albuminoids was high, the 

 carbohydrate content was low, and vice versa. 



The amount of phosphoric acid is always very slightly 

 ess then half of the total mineral matter present. Potash i.*, 

 again, very nearly half of the amount of phosphoric acid 

 present. 



The effect of polishing is ne.vt dealt with, and it is 

 pointed out that polished rice becomes poorer in all 

 constituents except soluble carbohydrates, which 

 iticrease a little. 



KICE .\S .VN .ARTICLE OF DIET. 



It might be supposed that the estimation in which any 

 variety of rice is held among the consumers, as evidenced 

 by its market price, would be mainly determined by its 

 nutritive value and its palatability. The latter term iuclude.> 

 culinary properties, such as flavour, consistence, appearance, 

 taste, etc., which cannot be definite!}' described, and are 

 rather difficult to observe accurately. 



As regards the nutritive value of rice, as revealed 

 by analysis, there is no doubt that, other things being 

 equal, the variety of rice which contains larger amounts of 

 albuminoids is more valuable, inasmuch as albuminoids, which 

 are the flesh-formers, are a more expensive form of 

 food than .starch. The relative nutritive value of a sample 

 of rice can thus be assumed to depend on its albuminoid 

 content. It was noticed, however, that no accurate relation 

 can be found between the chemical composition and the value 

 of a rice from the consumer's point of view. 



In a well-balanced ration, the relations between the 

 albuminoids, the oil and the soluble carbohydrates .should 

 vary within certain definite limits. Rice, however, in common 

 with other cereals, contains an extensive proportion of starch, 

 and is thus not suitable for use as t*e sole article of diet by 

 anyone. 



This holds not only from the point of view of the 

 organic constituents but also of the mineral ones, which are 

 the bone-formers. Rice is quite poor in this respect also. 



■ The importance of giving due consideration to the amount 



■ and composition of the ash of foods is very great, in order to 



ensure the supply of material for the proper development of 

 bone, and of the mineral constituents necessary for vital 

 processes — factors which have as much influence on the well- 

 being of animals as proteids, carbohydrates and fats in 

 appropriate quantities. 



Where a variety of foodstuff is used, the probability of 

 much injury being done by ignoring these asppcts of the 

 question is not very great. Happily the use of rice is nearly 

 always supplemented by the addition of other substances of 

 vegetable and animal origin, which often supply the deficient 

 elements 



An interesting characteristic of rice protein may be 

 mentioned here. It has recently been shown that in its 

 general aminoacid makeup, the protein of rice more nearly 

 resembles the majority of the proteins of animal tissues 

 than do the proteins of maize and wheat. This may explain 

 the fact that rice, in spite of its low protein content, furnishes 

 food for moe human beings than any other cereal. 



FERMENTATION OF SISAL WASTE. 



The increased attention that is being given to 

 sisal cultivation in some parts of the West Indies makes 

 the following note, taken from the Annual Report of 

 the Department of Agriculture, British East Africa 

 (1 ill 4- 1.5), of some local interest: — 



Kxperiments on the fermentation of sisal waste were 

 continutd this year but no very great progress was made 

 owing to lack of time and opportunity to carry out such 

 research work. 



The results, however, confirmed those previously 

 obtained. A preliminary analysis of the juice of leaves from 

 the Coast gave just about the same value for the sugar 

 content as was obtained for the Highland material, namely, 

 not more than .3-0 per cent. 



In Yukatan, where sisal waste has been fermented 

 with success, and alcohol from such has been put on the 

 market (according to report), the sugar content never went 

 below 94 per cent,, and at the end of their long dry season is 

 stated to have reached as much as 14'1 per cent. Most of the 

 alcohol was produced from leaves containing, on the average, 

 1 - per cent, sugar. 



As stated in last year's report, a yeast was isolated from 

 sisal plants which fermented a glucose solution, but which 

 was quickly killed in the sLsal extract. This was no doubt 

 due to the action of organic acids in the extract which were 

 present in great quantities. 



On neutralization with sodium carbonate and the 

 addition of a small quantity of glucose, it was found possible 

 for the yeast to live in the sisal extract; but no fermentation 

 was induced. 



Further work on more exhaustive analysis, and on the 

 neutralization and destruction of the organic acids was not 

 completed owing to the Analyst, for want of time, being 

 unable to carry out experiments of this nature. 



The work of discovering and isolating further yeast 

 ceased, owing to other pressing work. 



It would be of great interest to continue the work, for 

 the Analyst was by no means certain that the 3 per cent, 

 represented the whole of the sugars contained in the sisal 

 juice. ^Moreover, the organic acids present might prove of 

 importance (oxalic acid, fur example, if found to be present 

 n any quantity). 



