The quality of wheat grain depends on many factors. There are varietal characteristics, soil, climatic conditions, farming systems, post-harvest handling, duration, and regimes of storage. The farming system is one of the most important factors that influence grain quality. An ecological growing system will supply to reduce the cost of production and obtain quality and safe grain products. High technological indicators of wheat grain quality will be kept up for 1 – 3 years of storage.

The grain contains 14.3% protein, 29.2% gluten, deformation energy – 365 x 10^-4 J, general baking estimation – 4.2 marks. It is the wheat of valuable. The direction of use is grain for the food industry.

No chemical reagents were used for the studies.

For the study, a variety of soft winter wheat Poliska 90 was used. The owner of the variety is the Selection-Genetic Institute "Agriculture" of the National Academy of Agrarian Sciences of Ukraine. Variety is erythrosperm.

The moisture content of grain was determined by drying in the air oven SESH-3MU (company LLC "OLIS").

"Mass per hectolitre" was determined on a litter chondrometer with a falling load PH-2 (company LLC "OLIS").

The protein content was determined by Kjeldahl device UDK 129 with manual electronic control (company Velp Scientifica).

The number of falling was determining by device FALLING NUMBER 1900 (company Perten's).

The energy of the dough deformation, dough elasticity, and dough extensibility was determining by Alveoconsistograp NG of the company Chopin Technologies.

Grains were milled on Buhler MLU-202 Laboratory Flour Mill of the Buhler's company.

Samples were weighted by laboratory scales ADA320 (AXIS) from the company “Scales of AXIS Ukraine” with the 2^nd class of accuracy.

The grain samples were analyzed for the moisture content of the grain to ISO 712:2009 and test weight (called "mass per hectolitre") to ISO 7971-1:2009. The percentage of the vitreous kernel was determined according to the method given in ICC Standard No. 129. (1980) The percentage of vitreous kernels is determined by examining the crosssection of the grains. Vitreous grains appear dark and translucent, while opaque grains appear yellow and starchy. The percentage of vitreousness represents the mean of the 50 kernels × 2.

The grain samples were analyzed for the total content of crude protein in dry matter of grain according to the ISO 20483:2013, the content of wet gluten in dry matter of grain to the ISO 21415-1:2006, and the falling number method according to Hagberg-Perten to the ISO 3093:2009.

The remaining grains were milled on the Bühler laboratory mill (MLU-202 type). Wheat flour was used to determine deformation energy, dough elasticity, and dough extensibility.

Mathematical and statistical processing of experimental data was carried out in determining the criteria of Cochran's C test, Fisher, and Student's t-test. The accuracy of the data was determined using the Cochrane criterion, and the adequacy of the mathematical model was checked using the Fisher and Student criteria. The obtained data were further subjected to statistical analysis and the consequent evaluations were analyzed for a variance (ANOVA). The statistical differences between the studied variants were estimated through Tukey’s test. The Pearson correlation analysis was also carried out on these data. Statistical tests were evaluated at a significance level of α = 0.05 using Statistica 6.0 software (StatSoft, Inc., Tulsa, USA).

The main factor determining the orientation and intensity of physiological and biochemical processes during the storage of grain is its moisture content. Safety long-term storage of wheat grain is possible only at a moisture content not exceeding 14% (Leary et al., 2018; Ramanathan et al., 2018).

In our studies, the moisture content of wheat grain was 13.34 ±0.47% on average. Throughout the shelf life, the grain moisture of the studied variants did not change significantly (<0.9%) and was dependent on the relative humidity of air (Table 1). The research determined the effect on the grain moisture of the storage period and the precursors at the ecological and biological systems (Table 2).

Filling grain or grain with a high hectolitre weight has more endosperm and a higher yield of flour. Under unfavorable conditions for the formation of grain or seeds, the mass of peels in comparison with the weight of the grain increases, and the endosperm decreases (Dorofee, 1972; Bharti et al., 2016).

Before the storage, the wheat grain of all the studied variants had a very high hectolitre weight. The highest initial hectolitre weight values were in wheat grown after corn for silage of 81.73 kg and the lowest after the clover of 76.69 kg. The test criterion F (ANOVA) showed the most significant impact on this indicator was precursors at the ecological and biological growing systems.

No significant difference in hectolitre weight was in the grain of wheat grown at the industrial and ecological systems. We partially confirm of our data the research Dziki et al. (2017), about the absence of a clear impact of the growing system on hectolitre weight (Bober et al., 2020). The lowest hectolitre weight values were in wheat grains grown at the biological system of 79.27 kg, which significantly differed from the grain grown at two other systems. These deny data of Bilsborrow et al. (2013) about higher hectolitre weight at organic farming compared to conventional. At the same time, our studies point out a significant impact on the hectolitre weight of agricultural systems at all the predecessors (Table 2), thereby confirming data of other scientists (Zheplinska et al., 2020).

During storage of wheat grain, changes in hectolitre weight fluctuations depend on relative humidity and its changes were not significant. After three years of storage of wheat grains, almost all of the studied variants had a slight increase in hectolitre weight and after five – on the contrary, a slight decrease. Although several previously conducted studies by different scientists indicated that after 6 – 12 months of storage there is a significant reduction in hectolitre weight (Varella et al., 2017; Jafary, Szabo and Niks, 2006).

In our study, the test criterion F confirmed the absence of effect on the hectolitre weight of the shelf life.

The consistency of grain is of great importance for flour processing. The higher the vitreousness is then the greater the number of the fraction can be obtained from the grain, and in the future, it provides a larger yield of varietal flour. In the works (Casey et al., 2016; Marryat, 1907; Davoyan et al., 2012) found forms immune to rust, powdery mildew, and soot among Triticum dicoccum.

The best ability to give good yield to the cereals and high of flour varieties was at a grain of winter wheat grown after the clover (85% vitreousness), the worst at a grain – after corn for silage (69%). Equally, high vitreousness indexes were in grain grown at the industrial and ecological farming system and significantly lower than the biological system.

In the same way, confirming the data on the effect on the vitreousness index of the amount of fertilizer applied and the content of nitrogen in the soil at different predecessors (Khaneghah et al., 2018; Kirilenko, 2014).

In general, for all agricultural systems, the vitreousness of the grain was quite high, which makes it possible to obtain high yields of cereals and flour.

The glassiness is conditioned by the presence of protein. For insufficient quantity of it create a dense consistency (protein-starch complex), which shows virtuousness "transparent" for light penetration for light consistency (Vlasenko, Koliuchyi and Chebakov, 2005).

We found that after one year of storage of wheat grain, all options were to strengthen the consistency, which was expressed by a quantitative increase in the vitreousness index by 30%. This can be explained by the interaction of protein and starchy substances during the post-harvest maturing of grain (Kozub et al., 2017; Pirko et al., 2012).

Previous studies of the effective term of storage on the vitreousness of the grain indicate that vitreousness, in general, is a stable indicator (Mushtruk et al., 2020a, Palamarchuk et al., 2019). In our studies, also, in the three or five years of storage of wheat grain, the vitreousness remained almost unchanged.

The test criterion F indicated a significant effect on the vitreousness of wheat grain storage term and precursors and the absence of impact on growing systems (Table 2).

The protein content of wheat grain varied significantly depending on the predecessor and growing systems (Figure 1, Table 3). The highest protein content in wheat grain was provided by the predecessor peas – 14.54%, that was explained by the ability of peas in the process of vegetation to accumulate nitrogen, which is necessary for the formation of protein in the grain (Sukhenko et al., 2019). The predecessors of the clover and corn for silage provided significantly less protein in the grain.

A high index of protein content was in the grain of wheat grown for both the industrial system of agriculture – 14.55%, for the ecological – 14.23% and significantly lower than the biological – 12.72%. These results are in agreement with the results obtained by several scientists in previous years (Zheplinska et al., 2021a). However, Kihlberg et al., (2004) found that wheat grain grown under normal agricultural systems had lower protein content than organic. Also, there is the notion of the absence of influence of agricultural systems on protein content, or their influence was less significant than the influence of other factors (Mayer et al., 2015).

In our study, test criterion F (ANOVA) showed a significant effect on the protein content of all investigated factors (Table 4). The agricultural systems were the most influential on protein content, especially at the predecessor corn for silage. Great influence on the protein content had predecessors at the biological growing system.

It is important to preserve grain protein for a long time. After one year, the protein content increased significantly compared with the initial values (by 0.35%), which is explained by the transition of simple amino acids to complex proteins in the process of post-harvest maturing (Park et al., 2015). Three years of storage ensured the stability of this indicator. However, Oleinik and Davidyuk (2009) scientists noted a tendency to decrease the protein content of grain after 24 months of storage by 0.2 – 0.5%. After five years, the protein content has significantly decreased compared to the first year of storage and has not significantly differed from the initial data.

According to Menkova et al. (1995) in the grains of winter wheat, stored for eight years under normal conditions, noticeable changes in the biochemical composition did not observe. Insignificant changes in the content of protein during storage other scientists were noted (Ceseviciene and Masauskiene, 2009).

The main part of the proteins that included the grain presented the solutions in alcohol and alkali – glutenin and gliadin, which form the so-called gluten.

As can be seen from Table 3, wheat grain, grown for all agricultural systems, according to the predecessor peas contained the maximum amount of gluten (32.68%), in corn – the minimum (28.27%). The difference in the content of gluten in wheat grain was significant among all the predecessors. Most scientists explain this by the fact that winter wheat is demanding to the conditions of moisture and fertilizer, so its highest yields obtained when placed after perennial herbs, bean-cereal grass mixtures, and peas for grain (Palamarchuk et al., 2020).

The amount of gluten was significantly higher in grain grown at the ecological system (33.23%) compared to industrial (32.58%). The content of gluten in wheat grain grown at the biological system was significantly lower than at the ecological (6.6%) and industrial (5.95%). This confirms by scientists that the traditional system provides a significantly higher index of gluten than organic. In this case, the limiting factor in the system of organic cultivation is the provision of nitrogen (L- Baeckström, Hanell, and Svensson, 2004).

The dynamics of gluten content during storage are controversial. The variation in the content of gliadin and glutenin is probably due to changes in protein aggregation and their solubility. Kibar (2015) founded that the amount of gluten increases during the first two months and subsequently decreases. Other researchers have found a significant reduction in the content of gluten in wheat grains after three and eight months of storage. In our studies, during three years, the changes of gluten content in wheat grain were not significant, although the index increased somewhat after a year of storage and slightly decreased after three years. The amount of gluten in the grain decreased significantly after five years of storage compared to the first year (by 3.15%).

The test criterion F (ANOVA) showed the greatest influence on wet gluten content in grain the predecessors at the industrial growing system (Table 4). Also, was influenced strongly by the investigated parameter of growing systems, especially at the grain grown after the clover and corn for silage. The effect on the wet gluten content in grain of the predecessors and the term of storage at the biological system and also the term of storage at the predecessor peas were not essential.

The changes that occur with starch in grain significantly affect the quality of products. Formation and cleavage of starch is carried out by amylolytic enzymes, the degree of activity in grain determined by the index of the falling number. The winter wheat grain of all the variants had a low activity of amylolytic enzymes. The high falling number with insignificant difference between the variants of research, was in the grain grown for all agricultural systems and predecessors.

Significant changes in the falling number were after one year of storage of grain wheat – the index increased on 28 seconds. Further storage was characterized by a gradual increase in the falling number. Again, a significant increase was noted after five years of storage – by 28 seconds compared to the third year of storage and by 72 seconds compared to the initial data.

By our studies, we confirmed and supplemented the results of other scientists regarding the decrease in alpha-amylase activity and the increase in the falling number with an increase in the storage period of wheat grain.

Also, Linina and Ruza (2016) noted the dependence of the falling number from weather conditions, storage duration, and the amount of nitrogen fertilizer. Sulek and Cacak-Pietrzak (2018) argued that the activity of amylolytic enzymes is more dependent on the variety than cultivation technology. In our research, the test criterion F (ANOVA) shown a statistically significant effect on the falling number predecessors, growing systems, and term of storage (Table 4).

The evaluation of wheat flour at the mechanized or automated baking production has rheological properties of the dough, in particular deformation energy (W) or the energy used to tear the dough semi-finished. It determines the area of the alveogram and characterizes the baking power of the flour (Zheplinska et al., 2021b).

The specific deformation energy of the dough varies widely from 30 to 800 x 10^-4 J. In our studies, the highest rates of deformation energy were at the growing of grain after the peas' predecessor, insignificantly smaller than the clover (33 x 10^-4 J) and significantly lower than corn for silage (45 x 10^-4 J). Deformation energy indices did not differ significantly during the cultivation of grain at industrial and ecological growing systems (Figure 2, Table 5). Significantly lower were the indicators at the biological system: 41 x 10^-4 J compared with the industrial system and 38 x 10^-4 J compared with the ecological system. This agrees with the data of scientists about significantly higher baking properties in the traditional system, compared with organic, but denies the data of other scientists about the insignificant impact of growing systems on these indicators. At the same time, confirming the findings of L-Baeckström, Hanel and Svensson (2004), that nitrogen is the most limiting factor for the organic growing system.

Rose et al. (2011) found that grain of wheat retains its nutritional qualities up to 32 years, although they noticed a negative correlation of indicators with the time of storage. Mushtruk et al. (2020b) indicated a possible improvement of rheological properties during storage, especially at elevated temperatures. But González-Torralba et al. (2013) set only fewer changes of alveographic parameters during storage after 180 – 240 days.

In our studies, after one year of grain storage, there was a significant increase in the deformation energy (on 74 x 10^-4 J), after three years there was a slight decrease (on 14 x 10^-4 J) and after five years a significant decrease (on 42 x 10^-4 J) compared to each previous term.

The test criterion F (ANOVA) showed a significant influence of all investigated factors on the selected flour alveograph properties of winter wheat (Table 6). The greatest impact on deformation energy had storage period at the industrial system and peas predecessor. Also, predecessors at the industrial and biological systems of agriculture had a great influence on this index.

Dough extensibility (L) is the diameter of the test bubble during bursting. This indicator is due to the resistance of the gluten-free frame to spatial reorientation during dough formation and it is a converse characteristic to dough elasticity.

Indicators of dough extensibility differed considerably at the cultivation of wheat grain after clover and peas (on 2 mm), but at industrial and ecological growing systems (on 1 mm). Significantly lower dough extensibility observed in growing wheat grain after corn for silage (9 – 13 mm) and a biological system (6 – 7 mm). The grain storage process characterized a significant increase in the dough extensibility after one year of storage (on 11 mm) and a significant decrease – after five years (9 mm). This confirmed the data of Kolyanovska et al. (2019), which indicated the possible improvement of rheological properties during storage and data by Rose et al. (2011) – on the gradual decline of these indicators during long-term storage.

The most important for dough extensibility had the precursors at cultivating grain at the industrial agricultural system. Also, the great impact growing systems and storage periods on the dough extensibility indicator had on growing grain after peas.

Dough elasticity (P) is the maximum pressure created inside the dough at the time of its mechanical destruction during inflation in the form of bubbles. The value of this index quantitatively characterized the resistance of the gluten of the yeast dough to deform during fermentation and dough arise (Sheiko et al., 2019).

Indicators of dough elasticity differed significantly in the cultivation of wheat at industrial and ecological growing systems (on 3 mm) and substantially for the biological system (13 – 16 mm). It confirmed data by Krejčířová et al. (2007) about twice the amount of glutenins, which is responsible for the elasticity of the dough, in the grain grown under the traditional system, as compared to the organic. The indicator varies considerably depending on the predecessor. At the same time, the highest values were in the cultivation of wheat grain after peas, which provided a higher content of nitrogen for the formation of proteins in wheat grains.

The tendency of changes in dough elasticity was similar to deformation energy. The most significant changes in dough, elasticity were noted after one year of storage – it increased by 46 mm in comparison with the initial data. After three years of storage, we observed an insignificant decrease in the indicator. Significant reduction in dough elasticity was only after five years of wheat grain storage – on 23 mm compared with the third year of storage.

The greatest impact on the dough elasticity had the terms of storage at predecessors’ peas and clover and also at the biological system of agriculture (Sukhenko et al., 2017).

Table 7 presents the correlation coefficients between the physical, biochemical parameter of grain and alveograph properties of flour the winter wheat after 5 years of storage.

Pearson's correlation coefficients confirmed the strong negative effect of moisture on the hectolitre weight of wheat grain (r = -0.74), which researchers noted in past years. Simultaneously hectolitre weight had the highest positive correlation with protein content in grain (r = 0.68) and a noticeable positive correlation with deformation energy (r = 0.53).

It was found that the vitreousness index was very positively correlated with wet gluten content in grain (r = 0.96) and strongly with the following indices: deformation energy, dough extensibility, and protein content (r ≥0.80). This is confirmed by the data of the direct dependence of the content of the protein, gluten, and hence the baking properties of the flour from the vitreousness grain (Mushtruk et al., 2021b).

The results showed, that falling number in grain has a strong positive relationship with dough elasticity, dough extensibility, and wet gluten content in grain (r >0.70). This is a confirmation that the quality of starch and the activity of amylolytic enzymes of wheat grain and have a direct effect on the quality of the dough.

The main indicator of flour power is the quantitativephysical properties of gluten and protein content, which confirm the correlation coefficients. Protein content in grain is very positively correlated with the deformation energy (r = 0.96) and strongly with dough extensibility, dough elasticity, and wet gluten content in grain (r >0.70). Wet gluten content in grain had the highest positive correlation with dough extensibility (r = 0.82).