Vol. XV. No. 358. 



THE AGEICULTURAL NEWS. 



•21 



COMPOSITION AND KEEPING QUALITIES 

 OF CORN (OR MAIZE) MEAL. 



The production of kiln-dried corn in Antigua and 

 St. Vincent, and the large amount of g'orn meal imported 

 into all the West Indian colonies, render of interest 

 the following summary of a Bulletin on t^e composition 

 of corn meal manufactured bjr different processes, and 

 the influence of compGsit>ion on keeping qualities. The 

 Bulletin i.s No. 21o, issued from the Bureau of Chemistr}- 

 of the United States Department of Agriculture. 



The products of a white-corn mill may be arranged in 

 the following order in regard to acidity: fat, fibre, and ash, 

 beginning with the lowest percentage; grits, meal, tiour, feed, 

 and germ. They may be arranged in the following order in 

 regard to protein: flour, meal, grits, feed, and germ. The 

 percentage of nitrogen-free extract is not strikingly different 

 in the grits and meal, but is lower in the feed, and lowest in 

 the germ. 



Samples of meal taken from forty-one mills located in 

 thirty-two towns and .seventeen States are classified under 

 four heads: (1) whole-kernel, stone-ground meal; (2) bolted, 

 undegerminated meal; (3) degerminated, bolted, roller ground 

 meal ('cream meaf); and {-L) low-grade or 'standard' meal. 



Whole-kernel meal at the time of grinding is the same 

 in composition as the corn except in regard to moisture, but 

 soon develops a greater acidity. 



Bolted, undegerminated meal contains less fibre than the 

 corn, but no other general rule can be formulated owing to 

 the variable conditions of manufacture. 



Degerminated, bolted meal contains less protein, fat, 

 fibre and ash, but more nitrogen-free extract than the corn. 



Low-grade ('standard') meal contains sometimes more 

 and sometimes less of each constituent than the corn. 



Ton lots of degerminated, bolteil meal, with a range in 

 moisture content, were stored at Savannah and Chicago. The 

 lot containing f 6'86 per cent, of moisture showed an excess 

 of acidity in twelve weeks, a loss of fat in sixteen weeks, 

 and a musty taste in twenty weeks. The lot containing 1504 

 per cent, of moisture only slightly exceeded the limit for 

 acidity (30) in tvv'enty-four weeks, and did not suffer in taste 

 or appearance, while those of IS'-tl per cent, or less kept w'ell 

 in all respects up to the end of the experiment (twenty-four 

 ■weeks). 



Carload lots of degerminated, bolted meal, with 15'73 

 per cent, of moisture, showed an excess of acidity at 

 Savannah in eight weeks, and at Chicago in twelve weeks, 

 but did not suffer appreciably in quality. Highly dried 

 meal with 9'86 per cent, of moisture after twenty-four 

 ■weeks showed a maximum acidity of only 21 '8. 



Comparative tests with whole-kernel and degerminated, 

 bolted meal, undried and dried to different degrees, and 

 stored at Savannah and New Orleans, showed the superior 

 qualities of the latter. Even when dried to 10'79 per cent. 

 of moisture, the whole-kernel meal developed excessive 

 acidity in eight weeks, and became rancid in tvventy weeks, 

 ■while witJi 15'71 per cent, of moisture or higher, in addition 

 to becoming acid, it sooner or later heated and caked. The 

 loss in weight accompanying heating exceeded the loss of 

 moisture. 



Degerminated, bolted meal containing 13'78 per cent. 

 .or less of moisture kept in all respects for twenty-eight weeks, 

 and that containing 15^72 per cent., although it became stale 

 in twenty weeks, did not develop excessive acidity. The 

 ■undried meal containing 19^20 per cent, of moisture, although 

 it heated within tour weeks, unlike the whole-kernel meal 

 ■did not increase markedly in acidity. 



Meal of the two kinds milled April 1914 without drying, 

 and containing about 18^50 per cent, of moisture, spoiled 

 within two weeks at New Orlean.s. Only the ■ivhole-kernel 

 meal developed an excess of aciditj'. 



A study of all the results leads to the conclusion that 

 degerminated, bolted meal, containing not over 14 per cent, 

 of moisture and 1 per cent, of fat, as determined by the 

 method of the Association of Official Agricultural Chemists, 

 properly stored, should keep for six months; with a mois- 

 ture content of 15 per cent, it should keep three months. 

 Schindler's limit for moisture, viz., 13|- per cent., obtained 

 by drying in an open di.sli, corresponds to about 14i per cent, 

 by the method of the Association of Official Agricultural 

 Chemists. 



Whole-kernel meal, like cream, should be produced 

 locally and consumed soon after drying; properly dried, 

 degerminated meal, like btttter, keeps well during transpor- 

 tation and Ions storage. 



Storage of Manure. — The problem of the storage 

 and fermentation of manure has for long been a subject 

 of discussion, pits and covered courts each having 

 their advantages and disadvantages. A new system by 

 Dr. Giuseppe Beccari, of Florence, Italy, is described in 

 a recent publication from the Imperial Institute of 

 Agriculture, and consists in the storing of the manure in 

 turret-covered courts. The court is a rectangular structure 

 of masonry, divided internally into two compartments about 

 7 feet high. The floor is paved and provided with drains 

 covered with perforated bricks, through which air passes 

 upwards into the manure, while' the li(juid manure drips 

 through into a tank. In the top of each compartment there 

 is a trap-opening through which the manure is thrown. 

 Between the two trap-openings a turret is situated, with the 

 object of collecting and fixing the ammonia compounds 

 evolved from the fermenting manure, which enter by the 

 apertures. In the turret, shelves placed above each other 

 and fixed alternately to either side are charged with solid or 

 licjuid, alkaline or acid absorbents; these are collected from 

 time to time through a door or other aperture in the turret, 

 which has also openings at the top and bottom for the admis- 

 sion and escape of air. The manure is abundantly sprinkled 

 every four or five days with liquid manure from the 

 tank, and in forty-five to fifty days it is ready for use. 

 Manure made in this way has been found to contain 

 0'54 to 0'89 per cent, of nitrogen, while manure 

 made in the usual way is considered good when it 

 contains 0^45 per cent. Besides this, there is also the 

 nitrogen fixed by the absorbents in the turret From 

 the hygienic point of view this system is superior to 

 any other. It has been adopted in several parts of Tuscany, 

 where the cost of erecting such a covered court sufficient for 

 eight to ten head of cattle is about £26. The advantages of 

 the system are (1) that of fermenting the manure in a closed 

 space so that it attains immediately the high temperature of 

 158 to 167' F., evolving abundant ammonia and preventing 

 the development and action of denitrifying bacteria and 

 consequent loss of nitrogen; (2) th^at of collecting the 

 volatile ammonia compcunds, which are led into a special 

 chamber (the turret), where they are transformed into stable 

 ammonia salts or nitrates, by suitable absorbents, such as 

 clayey earth, peat, charcoal, gypsum, acid superphos- 

 phates, or an alkaline medium, and at the same time favour 

 the devolopment of numerous colonies of nitrifying bacteria, 

 (The Gardener's Chronicle for November 6, 1915.) 



