Cerealine

The cells composing the embryous membrane contain, as already stated, the cerealine, but after the germination they contain cerealine and diastase, that is to say, a portion of the cerealine changed into diastase, with which it has the greatest analogy. It is known how difficult it is to isolate and study albuminous substances. The following is the method of obtaining and studying cerealine. Take the raw embryous membrane, prepared as stated, steep it for an hour in spirits of wine diluted with twice its volume of water, and renew this liquid several times until the dextrine, glucose, coloring matters, etc., have been completely removed. The membranes should now be pressed and cast into a quantity of water sufficient to make a fluid paste of them, squeeze out the mixture, filter the liquid obtained, and this liquid will contain the cerealine sufficiently pure to be studied in its effects. Its principal properties are: The liquid evaporated at a low temperature produces an amorphous, rough mass nearly colorless, and almost entirely soluble in distilled water; this solution coagulates between 158° and 167° Fah., and the coagulum is insoluble in acids and weak alkalies; the solution is precipitated by all diluted acids, by phosphoric acid at all the degrees of hydration, and even by a current of carbonic acid. All these precipitates redissolve with an excess of acid, sulphuric acid excepted. Concentrated sulphuric acid forms an insoluble downy white precipitate, and the concentrated vegetable acids, with the exception of tannic acid, do not determine any precipitate. Cerealine coagulated by an acid redissolves in an excess of the same acid, but it has become dead and has no more action on the starch. The alkalies do not form any precipitate, but they kill the cerealine as if it had been precipitated The neutral rennet does not make any precipitate in a solution of cerealine--5 centigrammes of dry cerealine transform in twenty-five minutes 10 grammes of starch, reduced to a paste by 100 grammes of water at 113° Fah. It will be seen that cerealine has a grand analogy with albumen and legumine, but it is distinguished from them by the action of the rennet, of the heat of acids, alcohol, and above all by its property of transforming the starch into glucose and dextrine.

It may be said that some albuminous substances have this property, but it must be borne in mind that these bodies, like gluten, for example, only possess it after the commencement of the decomposition. The albuminous matter approaching nearest to cerealine is the diastase, for it is only a transformation of the cerealine during the germination, the proof of which may be had in analyzing the embryous membrane, which shows more diastase and less cerealine in proportion to the advancement of the germination: it differs, however, from the diastase by the action of heat, alcohol, etc. It is seen that in every case the cerealine and the embryous membrane act together, and in an analogous manner; we shall shortly examine their effects on the digestion and in the phenomena of panification.