MALT AS AN IMPROVER
Malt is a sprouted grain. The changes in matter that occur during seed germination are generally fairly well known; we have already referred to them many times.
In order to use insoluble, high-molecular-weight endosperm storage substances in the form of nutrition, the embryo that awakens to life must process them into soluble and easily perceived forms. For this, he has at his disposal various enzymes and, above all, the ability to form such enzymes in large quantities. During germination, the amount of enzymes increases markedly.
It is firmly established that the amount of both carbohydrate-degrading amylases, or diastases, and protein-dissolving enzymes (proteases) increases with the duration of germination. The action of these enzymes is manifested in the formation of soluble substances.
Starch is broken down into dextrins and malt sugar, and partly into grape sugar; protein substances pass into various, even less characteristic intermediate stages, into albumoses, peptones and amides. Associated with this change is the partial degradation of minerals, especially phosphates, into inorganic form. The processes can be analytically traced both by the increase in the amount of soluble constituents, and by the increased enzymatic strength that characterizes the grain.
How simple these growth processes are in general, how complex they are individually - and their mechanism is still not known.
It is known that the decomposition of starch is divided into 2 phases: liquefaction of swollen and gelatinized starch and subsequent saccharification. Both processes run in parallel, but the conditions favorable to them are completely different. While the optimum saccharification temperature is 45-50 °, the liquefaction of starch occurs faster - only at 60-70 ° C. At low temperatures, starch paste is thicker, at higher temperatures - more liquid. Now it is considered established that liquefaction occurs due to the appearance of another enzyme (cytase) along with amylase, and that both processes depend not only on the action of amylase
Further, it is still questioned whether the amylases of resting grain and malt are the same. Brown and Maurice see the difference in the fact that grain amylase at rest (translocation) dissolves starch grains without first corroding, that it has little or no effect on starch paste and only converts soluble starch, at an optimal temperature of 45-50 ° C, into sugar. In contrast, malt amylase corrodes and liquefies starch grains before saccharification, and its optimum temperature is 50-55 ° C, ie 5 ° C higher.
Recent studies (Chrzaszcz)) undoubtedly indicate that here we are talking in both cases, about the same enzyme, only with a difference in action. For the preparation of bread, an interesting fact is that in a dormant grain, the ability to liquefy is very insignificant; this has been repeatedly established. The process of protein breakdown is even less known in detail. The grain contains only a small amount of enzymes that dissolve the protein; action, they are very weak. In malt the proteolytic strength increases rapidly and the degradation very soon leads to the formation of amides. The formation of peptones is very insignificant, and even generally controversial.
Osborne's hypothesis that the alcohol-soluble protein of a dormant grain disappears rather quickly during germination, and that a new alcohol-soluble proteid of a different composition appears in its place, is finally refuted by Luers in his book ("Hordein and Binin of Barley"). in alcohol, the malt protein is a part of the undecomposed protein of the dormant grain. Later, a noticeable regular increase in the acid content is observed in the malt, which is caused partly by the formation of acid phosphates, and partly by the formation of organic acids (amino acids).
As for the technique of making bakery malt, it is basically very simple and, like the preparation of ordinary malt, does not require a lot of special experience in order to provide good improvers.
Well-refined grain, in most cases barley or wheat, is first washed and swollen, since germination can take place only with sufficient moisture.
This process is carried out with different durations, depending on the type of grain and on the type of process. Coated barley requires a longer softening (at a higher temperature 2 days, at a lower temperature 3-4 dmya); grain free from shells, such as wheat, requires a shorter time of about 24 to 36 hours. During this process, the grain must be given sufficient air access so that it does not suffocate.
The wet grain, ready to swell, is either scattered on the current, or placed in rotating drums, where the germination process takes place. It is very important to observe certain conditions here: the height of the grain layer, the regulation of ventilation, temperature, the duration of germination, etc. thanks to this, all growth processes are stopped.
The malt is “dried.” Drying should not occur at too high a temperature, since otherwise the malt enzymes are weakened or become inactive. The loss of enzymatic ability during drying is inevitable, but if the temperature is maintained at 40-50 ° C, the diastic force can be maintained up to 80-9b The main enzyme - amylase or diastase, is easily quantified by the diastatic strength and thus gives the opportunity to characterize individual malt preparations The action of the malt preparations, of course, corresponds to the value of the diastatic strength, but the importance of malt in baking is not limited to this.
The decisive factor is not the maximum of enzymes, but their optimum. It is especially necessary to observe the ratio of diastatic to proteolytic factors. No data have been published regarding those conditions in malt production that inhibit proteolytic enzymes and favor diastatic enzymes. It is also little known how certain varieties of grain affect one development or another, although these influences probably exist. All this remains the secrets of the manufacturers.
In any case, it is known that the action of malt in this respect is very varied, and the task of production in the manufacture of malt should be the possible limitation of the action of dissolving the protein.
The analytical constants for this evaluation of malt preparations are not firmly established. Methods for determining the proteolytic strength of malt preparations are especially unsatisfactory.
Test baked goods should be decisive.
The most perfect use of malt for baking purposes is undeniably in the preparation of extracts from malt.
The solutions obtained in this way contain all the active substances from all layers of the grain without the addition of shells and films.
Such malt solutions are retained only when, through appropriate thickening, they are so highly enriched in dry matter that the development of microorganisms is impossible.
Therefore, they are evaporated into thick extracts and sold. Naturally, a prerequisite for this concentration is that the temperature used to evaporate excess water does not exceed a known limit, otherwise the effect of enzymes decreases. Water extracts of malt are evaporated in a room with rarefied air, in which, depending on the degree of rarefaction, water, even at lower temperatures of 40 - 45 ° C, turns into steam. So, in general terms, the formation of diamalt occurs. The details of the preparation and processing of malt are unknown, and all the originality of the manufactured products is based on them.
Over the past decades, a number of malt extracts have been developed for baking purposes, proving how the use of malt preparations has taken root.
Below are tables of the composition of the Mzlcextracts, showing very different data (see table. P. 502). In this table, the following should be noted. Fluctuations in water content are very significant and should be borne in mind when evaluating maltz extract. For ash content, values of 1.65-1.77 are normal.
Increased ash content should be suspicious when using impurities, especially if the amount of phosphoric acid is different. The fluctuations, as can be seen from the above numbers, are significant. The titratable acidity, in terms of lactic acid, ranges between 1.24 and 2.28. These are huge differences. Here, of course, we are talking about a greater or. less acid impurity. It is important that the pH did not always run parallel to that found by titration; degree of acidity, which should not be forgotten when evaluating malt.
With regard to diastatic strength, we also see noteworthy differences; so there are extracts that practically do not have DS (diastatic force) at all, (since DS up to 30 almost does not indicate an increase in the enzyme content); Really diastatic extracts can be considered only those extracts that have, according to the old Linner method, 50 and more DS. On the other hand, DS of extracts rarely rises above 100. Extracts with 60 - 75 DS are normal. In extracts with a higher DS, there is a strong effect that destroys proteins.
The simplest use of malt is to grind it with the grain, or to mix flour-ground malt into flour or dough. Similar malt flours can be found commercially.
Malt flour can have very different effects.
It depends on the content of soluble substances and, above all, the enzyme. The enzyme is especially abundant in the outer parts of the grain. If one wants to preserve these amounts of enzyme in malt flour, then it is necessary to prepare malt flour of high yields, that is, add as many outer layers of grain to the flour as possible. Malt flour becomes dark, because shell particles, just like in the manufacture of flour, color the products in a dark color. If you grind malt into a fine white flour, then its activity also decreases. It is especially important here to pay attention to the limitation of the proteolytic force.
As for the mode of action of this most important improver, then, first of all, one must understand for oneself in which direction one can expect an influence on the process of making bread.
First, it is necessary to anticipate the effect of malt preparations on
fermentation process anyway. Thanks to the digestible substances in the malt, the yeast is provided with a large amount of necessary food and a rich substrate for fermentation. Due to the increase in the amount of enzymes resulting from the addition of malt to the dough, their effect is enhanced and supplemented, and, depending on the duration of their action, a new soluble, easily perceptible and fermentable substance is formed.
Therefore, from the point of view of accelerating the fermentation process, malt preparations can always be used. The advantages in this case will be: shorter fermentation time or savings on yeast (within known limits).
This acceleration of fermentation is not always beneficial for the volume of the bread. Not all flour produces a dough that responds to the acceleration of fermentation by increasing its volume; the dough, increasing in volume, can give a coarsely porous, coarse crumb.
In most cases, accelerated fermentation is reflected in an increase in the volume of the bread.
Further it is necessary to trace the following actions of malt enzymes. Accelerated decomposition of starch favors the formation of a large amount of soluble carbohydrates, as well as the formation of a crust, since caramelization and brittleness depend on the content of sugar substances. The attractive brown color of the bread, the elasticity and vibrant shine of the crust are also advantages to be noted when using malt.
The action of the enzyme is also manifested in the ability to liquefy. Starch "opens up" more, so to speak, it becomes more accessible to swelling and gelatinization, water binds more strongly and bread can stay fresh longer. The fact that during the baking process not all the starch of the flour is completely gelatinized was mentioned earlier; it is known that the degree of gelatinization can change, for example due to the admixture of gelatinized starch.
A similar effect can be caused by an increase in enzymatic activity. Equally important is the effect that malt has on flour gluten due to its enzyme power.
Enzymes that dissolve protein substances become especially active due to the germination process. Their action is expressed in the decomposition of gluten, in its translation into a more mobile form; eventually it turns into soluble protein substances. Intermediate stages are still capable of swelling, but they already do not swell into a coherent viscous mass.
Gluten is not washed out of malt flour.
Regarding the effect of malt on the dough, the following must be said: if the gluten of the flour is strong and capable of resisting, but not stretching enough, then the protein-dissolving effect of the malt is manifested in softening the gluten and increasing its extensibility.
If we are dealing with soft-gluten flour, the gluten of which is more susceptible to the action of protein enzymes, then the increased proteolytic power of the malt may soften it too much. The dough will blur, the bread will not have enough elastic, even and loose crumb. but the latter will be rough and with irregular pores.
In extreme cases - most clearly "this is seen in large breads - shortcomings appear that completely coincide with those obtained with an admixture of a large number of germinated grains. A weak, highly hydrated gluten does not have sufficient strength to resist to retain carbon dioxide, the crumb settles, the gas forms under large spaces in the upper crust; or the cohesion of the dough becomes insufficient and the crumb bursts under the pressure of the gas.
Malt is an improver, therefore it is directly related to baking.
It works too vigorously to be added to flour in mills, which has sometimes been recommended and even practiced. This is not true.
By storing and preparing the grain, they try to provide flour stability, and on the other hand, they are not afraid of such impurities that naturally weaken this flour stability (Adding malt during short storage does not harm if the flour is sufficiently dry (14%); but the miller cannot know , as
for a long time and how they will store this flour.
If we consider the effect of malt as an improver, then its effect is observed in three main directions:
1) the ability of starch and gluten to absorb water increases,
2) soluble substances are formed, which enhances fermentation,
3) caramelization is enhanced.
This applies to all stages of bread making; if we imagine the reasons for these actions, it becomes clear that we are dealing with nothing else than the acceleration and revitalization of the processes on which the baking process is based. This explains the positive effect of this enhancer.