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Section 3. Food processing industry
Kakhramon Sanoqulovich Rakhmonov, Science researcher, faculty chemical technological, Bukhara engineering technological institute, city Bukhara.
Isabaev Ismail Babadjanovich, Doctor of Technical Sciences, Professor faculty chemical technological, Bukhara engineering technological institute, city Bukhara.
Bukhara engineering-technological institute E-mail: [email protected]
Wheaten ferments spontaneous fermantation in biotechnological methods
Abstract: In article are shown results of research of biotechnological properties of wheaten leavens of spontaneous fermentation (in the example of pea-anisetree leaven) and their analysis. Also is established influence of the given type of leavens on the basic biopolymers of the flour, on the property of the pastry and quality of bread from wheaten flour.
Keywords: Bread, microbial contamination, the spontaneous fermentation, bakery products
In modern conditions of an intensification of tech- Pea-anistree leaven on traditional technology was
nologies ofbread production in regions with hot climate prepared.
and ecologically adverse zones, requirements to biotech- The mixture of peas and anistree was filled in with
nological properties of flour half-finished products, in particular wheaten leavens have raised. Traditionally at preparation of national bakery products in Republic of Uzbekistan leavens of spontaneous fermentation are used. The greatest distribution has received pea-anisetree leaven, which technological potential practically is not learned. Pea-anisetree leaven concerns to polystrain spontaneously soured leavens. This type of leavens is characterized by instability of biotechnological indicators of quality, and even short storage is accompanied by decrease in their barmy activity and development of nonspecific microflora for the wheaten pastry.
1 l of water in temperature 80±2 °C, surface was strewed with flour and mixture maintained at temperature 30±1 °C within 24 hours. Fermented leaven pounded to homogeneous mass and added a nutritious substratum. A substratum for leaven prepared from 100 g of wheaten floor of the second grade, 200 ml ofwater, ferment preparation of Amilorizin P10x (0.01% to weight of flour in the mixture) and cultivated at temperature 28±1 °C. In each 24 hours within 8 days in leaven without updating were defined titratable and active (pH) acidity, mass fraction of sugars, quantity of yeast and acid-forming bacteria, and their regenerative activity.
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8 -6 -4 -2 -0
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1 days 2 days 3 days 4 days 5 days 6 days 7 days 8 days Figure 1. Dependence of glycogenesis (% on SV) in leaven from duration of cultivation (days)
Results of research are represented in drawing and presented at tab. 1-4.
The analysis of experimental data (fig.) has shown that in the first days of fermentation the mass fraction of sugars in leaven made 7.8 ... 8.2%, then their maintenance naturally decreased, and by the fermentation end was within 1.2 ... 1.5% that is caused by active accumulation of a biomass of microorganisms.
It was established (tab. 1) that the leaven which has started to fermentation spontaneously, reached optimum acidity only on 4-5 days. Thus bacteria were differed the best regenerative activity which made 40-35 minutes, then natural deterioration of the given indicator was marked.
Table 1. - Indicators of quality of leavens at spontaneous fermentation
The name of indicators Values of indicators of quality of leaven at fermentation, during days
Initial 1 2 3 4 5 6 7 8
Acidity 1.6 10.0 12.6 15.0 17.5 17.0 22.0 26.8 32.4
pH 6.30 3.70 3.65 3.55 3.50 3.50 3.40 3.00 2.80
Quantity of acid-forming bacteria, million/g - 226 1329 2385 2320 2769 2851 2512 2192
Restorative activity, minutes - 70 65 50 40 35 55 60 75
Plating of biologically active mixture on diagnostic medium made in 3 multiple frequencies. As diagnostic mediums were used meat infusion agar and mash agar. Plating was observed since 4 hours after preparation of a mixture and further in each 24 hours within 5 days. Mixtures stored at temperature 28±1 °C.
Microbiological plating on firm mediums, mi-croscoping and subsequent identifications of microorganisms shown that within 5 days of cultivation in leaven remained the various microflora: rod form bacteria, yeast, moldy mushrooms.
In information from specialized sources (1.2) were defined that in spontaneously soured wheaten leavens dominate family of Enterobacteriaceal bacteria, fermenting sugar with formation of carbon dioxide, hydrogen and quantity of organic acids (lactic, acetic, formic and succinic acids).
Simultaneously in the medium started to breed barmy cells which in the process beginning were present only at individual examples. In leaven yeast of sort Saccharomyces and Zygomycetes has been found out. The given microorganisms, along with bacteria and microscopic mushrooms, contain in the flour. On the
Table 2. - Formation and consumption of si
average the quantity of yeast of sort Saccharomyces in the first days of maturing made 16-106 ... 18-10 6. Zygomycetes — 10-10 6 ... 12-10 6 cells in 1 g of leaven. In process of increase in a period of storage of leaven was marked gradual dying off of barmy cells of both sorts so after 3 days the quantity of cells of cultural race of yeast Saccharomyces has decreased to 15.8 -10 6. and Zygomycetes — to 3.4 -10 6 cells in 1 r leavens. The parity of bacteria and yeast on 1, 3 and 5 days of cultivation made accordingly 13:1. 151:1 and 181:1.
Because work is directed on studying of possibility of use of leavens of spontaneous fermentation as an alternative substitute of yeast, have been conducted comparative researches of properties of the pastry and condition of the basic biopolymers of a flour in variants without leaven, on leaven without yeast, on leaven and yeast at a parity 1:1.
For intensification of the process of pastry preparation it is important that by the fermentation end in the pastry there was enough quantity of sugars. Therefore, was studied influence of investigated leaven on dynamics of change of the maintenance of sugars in half-finished products (tab. 2).
;ars at fermentation of half-finished products
Variants The maintenance of sugars,% on SV
In dense sourdough In sourdoughless ' pastry
Initial In 3.0 h In 5.0 h Initial In 3.0 h In 5.0 h
Mixture of a flour, water and salt 1.9 - - 1.5 - -
With addition: - Yeast 2.4 3.4 2.0 2.2 2.7 1.4
- Leavens 2.0 4.8 3.4 1.9 3.6 2.9
- Yeast and leaven 2.6 4.0 2.9 2.4 3.1 1.8
Comparison of the data on consumption of sugars by microorganisms shows that in half-finished products with yeast sugar are much more intensively consumed than with leaven and a mixture ofyeast and leavens. So, in 3 hours of fermentation the residual maintenance of sugars in sourdough and the pastry in variants with leaven exceeded similar value in variants with yeast and yeast with leaven, accordingly, on 1.4 ... 0.8 and 0.9 ... 0.5%.
The increase in duration of fermentation of half-finished products in variants with leaven and yeast with leaven
The above-stated suggests that changes in the pastry with leaven are caused basically by acid hydrolysis of albuminous connections of the flour, caused by the products of vital activity of acid-forming bacteria.
Further have been prepared the dough from first-rate wheaten flour in sourdough and sourdoughless ways. At sourdough way of pastry making leaven was brought in sourdough in quantity of 4% to prescription quantity of the flour, the pressed yeast — in the dough, and at sourdoughless way — 8% ofleaven to prescription quantity of the flour. As the control samples without leaven served.
Entering mesophyll leavens in an initial stage of pastry making as at sourdough so and sourdoughless ways reduces pH indicator of half-finished products to the values 5.5-5.3 which are optimum for vital activity
even to 5 h did not lead to an exhaustion of a mass fraction of sugars, moreover, in the given variants the maintenance of residual sugars exceeded similar value in half-finished products on yeast on 0.9 ... 1.4% at sourdough way of pastry making and on 1.5 ... 0.4% — at sourdoughless way.
Natural decrease in an exit crude and dry gluten in the process of the pastry maturing, prepared with addition of spontaneously soured leaven, and also increase of the maintenance ofwater-soluble substances concerning the control sample (tab. 3) is established.
of microorganisms. At such pH values of flour half-finished products inhibits action of a-amylase that allows receiving qualitative production from a flour with raised autolytic activity.
Use of mesophyll leavens leads to reduction of durability of structure of the pastry that, obviously, is connected with an intensification of processes aerogenesis, hydrolytic splitting of biopolymers of the flour, increase of the maintenance of water-soluble substances in the pastry.
Influence of analyzed leaven on quality ofbread from the first-rate wheaten flour was estimated by results of laboratory baking quality test. Finished goods analyzed through 16-18 h after the baking quality test.
Results of researches are presented at tab. 4.
Table 4. - Influence of leaven on quality of bread from the first-rate wheaten flour
The name of indicators Indicators of quality of the bread prepared
in the sourdoughless way on dense sourdough
Without leaven With leaven Without leaven With leaven
Humidity,% 43.80 43.80 43.60 43.70
Acidity, degree 2.60 3.00 3.10 3.40
Porosity,% 69 70 70 74
Specific volume, sm3/g 2.44 2.59 2.60 2.74
Stability of shape (N: D) 0.44 0.45 0.45 0.48
Organoleptic estimation, point 78 80 80 84
Table 3. - Change of albuminous connections of the flour in the process of pastry fermentation
Variants Duration of fermentation, h Quality indicators of gluten The maintenance of water- soluble sub-stances,% on SV the pastry
Quantity of gluten from 50 g of the pastry, r The maintenance of gluten,% on SV the pastry Hydration abil-ity,% Deformation of compression, Unit of IDK
The crude The dry
Mixture of a flour, water and salt 0 10.23 36.8 13.9 165 65 12.1
3.0 10.11 36.4 13.8 164 71 14.8
With addition: - Yeast 0 10.04 36.1 13.9 160 65 11.7
3.0 9.15 33.0 13.1 152 70 12.7
- Leavens 0 10.10 36.2 13.9 160 64 13.3
3.0 6.63 23.8 9.6 148 43 19.2
- Yeast and leaven 0 10.00 35.9 13.8 160 64 13.7
3.0 5.80 20.8 8.6 142 45 17.2
It is established that the improving effect of action of leaven depends on a way of preparation of the pastry.
From results of the researches resulted in tab. 4 follows that the bread with the best quality is received at use of sourdough way of pastry making with entering of leaven in dense sourdough, and yeast — in the pastry. The increase in specific volume of bread on the average on 5.4% and porosity — on 5.7%, and improvement of structurally-mechanical properties of a crumb is established, products were characterized by lighter color of a crumb, strongly pronounced taste and aroma in comparison with the similar production prepared on dense sourdough without leaven.
As a result of the carried out researches it is established that leavens have an influence to the condition of the basic biopolymers ofthe flour, intensity of their acid hydrolysis, and structurally-mechanical properties of the pastry.
Sharing of yeast and leavens is especially effective at sourdough way of pastry making that will allow to intensify technological process of preparation of bread, to lower pH indicator of the half-finished products to values 5.5 ... 5.3 at which decreases activity of of a-amylase and is synthesized sufficient quantity of sugars for proof and baking.
Also it is established that irrespective from the way of pastry making, use of investigated leaven of spontaneous fermentation promotes improvement of quality of finished goods.
The way of preparation ofbread on dense sourdough with entering of lactic leaven in sourdough, and yeast in the pastry has been recognized as the optimum way. The given way allows receiving finished goods with stable quality, which are meeting the requirements of State Standard 27842-88.
References:
1. Matveeva I.V., Belyavskaya I.G. Biotechnological basis of preparation of bread. - M: DeLi print, 2001, P. 150.
2. Bogatyryova T.G., Polandova R. D. Novelty in production of wheaten bread on leavens. - M: CSRITER ofbakery products, 1994, P. 45.
