Study of industrial enzyme improvers of the rheological properties of baking flour and the quality of finished products

. In today's discerning consumer market, flour milling has evolved beyond merely meeting established standards; it demands an understanding of evolving consumer needs and the ability to tailor products accordingly. A prominent global challenge lies in ensuring consistent wheat quality, particularly in addressing the prevalence of sprouted grains that compromise gluten quality. This necessitates a more rigorous scientific approach, encompassing novel methodologies and dedicated research initiatives. To address these hurdles, this article proposes a comprehensive strategy that leverages enzyme improvers and rheological studies of elastic properties, exemplified by the Alveolab Alveograph. Through a series of test bakings of tin bread, the impact of various enzyme additives, including Kazenzym 26007, Kazelco, AlphamaltVC 5000 Sn, and Alphamalt HCC, will be evaluated at varying dosages.


Introduction
Fluctuations in wheat quality leads to non-standard production of baking flour; this can be caused by various factors, such as weather conditions, cultivation technology, storage and processing conditions.Adverse effects on wheat can lead to sprouting, frost damage, low gluten content and quality.This, in turn, leads to a decrease in the technological properties of bakery products, deteriorates their appearance, taste, aroma and nutritional value; products made from such flour turn out dry, hard, dark and tasteless [1].
Due to increased moisture, sprouted grain becomes a favorable environment for the active proliferation of microorganisms, which affects the quality of future flour products.Modern baking technology using sourdough starters provides opportunities for enriching bread, expanding its range and ensuring microbiological safety [2].
To address the inconsistent quality of bakery products, the incorporation of complex enzyme improvers is essential.These specialized additives play a key role in bakery production by influencing the structural properties of the dough.
Enzyme improvers are specialized additives that catalyze biochemical reactions in dough, enabling bakers to overcome various challenges during the fermentation process.These additives address fluctuations in flour quality, gas-forming ability, and gas-holding capacity, ensuring the consistent production of high-quality bakery products.
The chemical composition of enzyme improvers can vary, including amylases, proteinases, lipases, hemicellulases, and others.These enzymes are classified as "processing aids" rather than food additives, indicating that their primary function is to modify the properties of dough during the baking process.While trace amounts of enzyme improvers may remain in the final product, their presence is considered safe for human consumption provided they do not pose an unacceptable risk to health.
Enzyme improvers can be classified into two categories based on their origin: natural and chemical Chemical enzyme improvers are synthetically produced substances that exert specific effects on dough properties, such as oxidation, reduction, or emulsification.They can affect the structure of flour proteins, increase the volume and porosity of products, improve appearance and taste, prolong its freshness and shelf life.
Natural enzyme improvers are derived from plant or animal sources and may contain minerals, antioxidants, prebiotics, probiotics, and other beneficial components.These components help improve dough rheology, enhance the aroma and taste of bread, increase its nutritional value, and improve microbiological stability.
It is important to consider that certain additives can trigger allergic reactions or increase the calorie content of finished products.Therefore, chemical and natural baking improvers exhibit distinct characteristics and functionalities.The choice of either type of improver depends on the manufacturer's goals and objectives, as well as the consumer's preferences and requirements.
Integral rheological indicators of the dough, reflecting its structural state throughout the entire technological process, enable the prediction of the quality of the future bakery product [3].
It has been established that protein substances present in flour undergo hydrolysis to a certain extent under the influence of proteolytic enzymes.In dough prepared from standardquality flour, this process proceeds slowly, primarily resulting in structural modifications to the protein molecule, with minimal hydrolysis of proteins to amino acids.Within the dough, protein hydrolysis contributes to enhanced rheological properties.Moreover, the proteolytic process in dough plays a crucial role in melanoidin formation [4].
The presence of specific chemical groups, such as sulfhydryl, amine, and hydroxy groups, in proteins influences the rate of their breakdown by proteolytic enzymes.If these groups are somehow removed from the protein molecule, the protein's susceptibility to enzymatic action is altered [5].
The objective of this study is to investigate the impact of enzyme improvers on the properties of flour utilized in the baking industry, as well as on the quality of the finished goods.
Within the scope of this research, it is expected to perform the following tasks: -evaluate the influence of enzyme improvers on the organoleptic properties of bakery products derived from wheat flour.
-analyze the effect of enzyme improvers on the rheological characteristics of wheat flour.
Object of the study: premium wheat flour, containing enzyme improvers of natural and chemical origin.Subject of the study: analysis of the influence of enzyme improvers on the rheological and quality indicators of tin bread.

Materials and methods
Alveographic measurement of the elastic and plastic properties of premium baking wheat flour was carried out using an AlveoLab device according to the international standard ISO 27971:2023.A flour sample weighing 250 grams is placed in the dough mixing chamber of the alveograph, where, depending on the humidity of the original sample, a 2.5% saline solution with distilled water is automatically supplied and kneading is carried out [6].
The moisture content was determined using the EM-10 device according to the State standard (GOST) 9404-88, the prepared flasks with flour were dried in a heated oven at a temperature of 130°C for 40 minutes, after time had elapsed and the flasks were cooled in a desiccator, the humidity was determined to be 14.6% [7].
The subsequent step involves the manual extrusion of the prepared dough, resulting in five individual pieces.These formed samples are then placed within a proofing chamber, where each piece undergoes automatic inflation until the resulting bubble bursts.The entire process of dough ball creation and subsequent rupture is recorded in the form of graphs and numerical rheological indicators.This information is displayed on the system's integrated display screen.The operator's involvement takes approximately 20 minutes, while the total duration of the elastic and plastic property determination process is approximately 40 minutes.Figure 1 illustrates the key parameters of the alveogram.1.
Enzyme improvers Kazenzym 26007, Kazelco, AlphamaltVC5000Sn and Alphamalt HCC from the German manufacturer Mühlenchemie GmbH&Co.KG were used as improvers for tin bread.Characteristics of improvers are presented in Table 2. Hemicelluloses are a group of enzymes classified as hydrolases.They catalyze the process of hydrolysis of polysaccharide, which is an integral part of plant cell walls and belongs to the so-called non-starch polysaccharides.Hemicelluloses contribute significantly to optimal gluten structure and gas-forming ability of the dough during kneading, helping to increase the volume of resulting baked products.Additionally, they can extend the shelf life of baked goods.Alpha-amylase promotes the random hydrolytic cleavage of starch bonds, resulting in the formation of low molecular weight dextrins.These dextrins under the influence of alpha-amylase slow down the retrogradation of starch.During the baking process, starch undergoes structural changes that influence the yield of the final product [8].
Ascorbic acid in dough creates a redox system with a long-lasting effect, that promotes gluten strengthening and enhances fermentation processes, which in turn increases the biological value of the resulting bakery products [9].

Literature review
Numerous studies by both international and domestic researchers have investigated the impact of enzyme improvers on flour's baking properties and the quality of baked goods.D. Zhigunov, M. Mardar, and V. Kovaleva employed enzyme preparations containing amylase and hemicellulase activity, along with the sulfur-containing amino acid cysteine, as baking improvers.Their study evaluated the influence of enzyme improvers on flour properties using laboratory bread baking experiments.The best results were achieved with medium dosages of enzyme improvers, resulting in a 1.8-fold increase in bread volume from 2.4 to 4.3 cm³/g [10].
Z.Sh.Mingaleeva, N.G.Khalikov, N.R. Zalyaliev studied the effect of the enzyme improver "Panifarin" on the production process and the quality of Arbat buns made from premium wheat flour.Panifarin, composed of dry wheat gluten, swelling wheat flour, and , 020 (2024) BIO Web of Conferences MSNBAS2023 https://doi.org/10.1051/bioconf/2024820201818 82 ascorbic acid, reduced dough fermentation time by 33% compared to the control without the additive.It also increased the specific volume of the buns by 2.3-12.7%.The optimal dosage was determined to be 1.0% by weight of flour [11].
F.A. Bischokova optimized the concentration of enzyme improvers "Mazhimix" for baking applications.Baking improvers contained various components, including α-amylase, hemicellulose and ascorbic acid.As a result of a full organoleptic and physico-chemical assessment, she came to the conclusion that the use of "Magimix" additives in certain proportions significantly improves the quality of the product, increases shelf life and freshness indicators [12].
By employing xylanase and β1,4-glucanase enzymes, Nina Schrögel-Truxius demonstrated that not only can the separation of wheat starch's starch and gluten phases be enhanced, but also the properties of gluten can be altered.Her findings revealed that the use of enzymes influences gluten's physical and chemical characteristics [13].
In a study by M. Sarparast and B. GhiassiTarzi, a complex enzyme comprising glucose oxidase, transglutaminase, and phospholipase was employed as a dough improver.To optimize the combination of these three enzymes, the researchers utilized the optimal response surface design (RSM) method.Their findings revealed that this enzyme complex effectively enhances dough stability, boosts water absorption capacity, and improves rheological properties [14].
In their research, P.N.Kucherenko and N.V. Stepycheva studied the impact of enzyme improvers on wheat flour, particularly α-amylase and β-amylase, on starch retrogradation.Their findings revealed that α-amylase addition extends the freshness and shelf life of baked goods by 15-33%, while β-amylase enhances the fermentable carbohydrate content of dough pieces and improves the dimensional stability of baked products [15].
T.G.Kolupaeva and M.V. Klevets conducted research on the effects of amylolytic enzymes during wheat bread production.Their findings demonstrated that these baking additives positively impact the organoleptic characteristics of bread, extend the freshness of finished goods, and minimize baking and shrinkage losses [16].
Through their research, N.V. Stepychev and I.A. Lazovenko developed an enzymatic baking improver utilizing α-amylase, guar gum, and xanthan gum.Their findings were derived from trial baking of bread samples.The improver was shown to influence flour and dough constituents, leading to alterations in structural properties.The incorporation of this additive contributed to enhanced bread quality, increased volume, prolonged freshness, and extended shelf life up to 72 hours [17].

Results and discussion
Following rheological testing at Mühlenchemie GmbH&Co.KG's laboratory, the optimal dosages of various enzyme improver combinations per 500 g of flour were established.
Table 3 summarizes the wheat flour samples with varying enzyme improver combinations.Alveograms of all samples of wheat flour with the addition of enzyme improvers on the Alveolab device are presented in Figure 2.  4. Indicators of elasticity (the ability of gluten to return to its original state after deformation) and extensibility (the ability of gluten to elongate) play a key role in the quality indicators of future tin bread.
The rheological indicators of elasticity (P) and extensibility (L) of all variants of wheat flour are presented in Figure 3.

Fig. 3. Rheological indicators of elasticity (P) and elongation (L)
As shown in the diagram, sample B with the addition of Kazenzym 26007 0.04 g and Kazelco 0.002 g to wheat flour has the highest degree of elasticity (P = 133 mm), and the lowest extensibility (L = 88 mm) and, accordingly the best ratio of elasticity to extensibility (P/L=1.51) of all the studied samples.The lowest performance among all in terms of the ratio of elasticity and extensibility was shown by sample A of wheat flour without adding additives (P/L=1.13).
One of the key criteria that determines the properties of flour is baking strength; this ability is determined by certain structural and mechanical characteristics of gluten.The strength of the flour affects aspects such as shape, volume, porosity and overall quality of the future product.
The rheological indicators of baking strength (W) of wheat flour of all options are presented in Figure 4.The data obtained from the curved lines of the alveogram make it possible to predict the best version of the bakery product.
Following the rheological evaluation, we proceeded to bake tin bread.The recipe consists of: 500 g of flour, 7.5 g of dry yeast, 7.5 g of salt, and 300 g of water (maintained at a minimum temperature of 20°C).All ingredients were combined and kneaded in a dough mixing machine for 9 minutes.The dough was then proofed in a MIWEGR proofer at 40°C for 55 minutes.Finally, the loaves were baked in a MIWECONDO brand bakery cabinet for 40 minutes at a temperature range of 210-230°C.

Table 5. Organoleptic evaluation of tin bread samples
Organoleptic analysis of tin bread using enzymatic improvers showed the following: all bread samples showed good appearance, correct shape, without lumps or traces of unkneading, smooth surface, taste and smell appropriate for this type of product.
In the control sample A of tin bread without the use of improvers, and in the sample C with the addition of AlphamaltVC 5000 Sn -0.025 g, Alphamalt HCC -0.01 g, and Kazelco -0.0025 g, the dough was sticky when kneading.The crumb of the control sample had large uneven porosity.The volume of the product of sample C increased by 7%, the porosity is average, uniform, thin-walled, the crumb did not crumble in comparison with the control.
Sample B of tin bread with the addition of Kazenzym 26007 -0.04 g and Kazelco -0.002 g, and sample D with the addition of AlphamaltVC 5000 Sn -0.025 g, Alphamalt HCC -0.01 g, Kazelco -0.005 g had a non-sticky dough, the volume of products increased by 10 % compared to control.
The wheat flour sample with the addition of Kazenzym 26007 -0.04 g, Kazelco -0.002 g showed the best quality indicators compared to the others, which was confirmed by test baking, where a sample of tin bread was characterized by better uniform porosity, internal crumb structure and dimensional stability.

Conclusions
As a result of studying the influence of enzyme improvers on the rheological properties of baking flour and the quality of finished goods, the following conclusion can be drawn: samples of wheat containing enzyme improvers exhibited superior rheological characteristics compared to the control sample.The quality of finished goods with enzymes was also higher in comparison with the control sample.In all samples with improvers, an increase in the volume of bread and an improvement in the internal structure of the crumb were observed.Some bread samples, like the control one, had uneven porosity (sample D) and sticky dough (sample C).Among all samples, sample B, supplemented with enzyme improvers Kazenzym 26007 (0.04 g) and Kazelco (0.002 g), emerged as the most favorable and effective option.This combination yielded bread with superior quality indicators, including enhanced dough stability, a 10% increase in bread volume, improved porosity, and an enhanced internal crumb structure.

Fig. 1 .
Fig. 1.Basic parameters of the alveogram:: P-elasticity; L-extensibility; P/L -elasticity to extensibility ratio; L.e. -elasticity index; W -baking strength Classic tin bread made from premium wheat flour was chosen as the finished goods to determine the rheological parameters of flour.Standard alveographic indicators of tin bread are given in Table1.

Fig. 4 .
Fig. 4. Rheological parameters of baking strength (W) of wheat flour Sample B (W=432 10-4J) using enzyme improvers in the dosage of Kazenzym 26007 0.04 g and Kazelco 0.002 g exhibits the highest baking strength of wheat flour among all samples.The worst indicators of baking strength were shown by the control sample A without additives (W=424 10-4J).

Fig. 5 .
Fig. 5. Rheological indicators of elasticity index L.e.As evident from the alveogram curves, sample (D) of wheat flour treated with enzyme improvers AlphamaltVC 5000 Sn -0,025 г; Alphamalt НСС -0,01 г; Kazelco -0,005 (L.e.=64%).Conversely, sample (A) without any additives demonstrates the lowest elasticity index (L.e.= 61%)The data obtained from the curved lines of the alveogram make it possible to predict the best version of the bakery product.Following the rheological evaluation, we proceeded to bake tin bread.The recipe consists of: 500 g of flour, 7.5 g of dry yeast, 7.5 g of salt, and 300 g of water (maintained at a minimum temperature of 20°C).All ingredients were combined and kneaded in a dough mixing machine for 9 minutes.The dough was then proofed in a MIWEGR proofer at 40°C for 55 minutes.Finally, the loaves were baked in a MIWECONDO brand bakery cabinet for 40 minutes at a temperature range of 210-230°C.Samples of baked tin bread loaves are presented in Figure6.

Fig. 6 .
Fig. 6.Samples of baked tin bread using enzyme improvers: А -control version of pan bread without enzyme improvers;

Table 2 .
Characteristics of enzyme improvers

Table 3 .
Flour samples with added enzyme improvers