One of the important factors affecting the quality of bakery products is the gas-holding capacity of flour which essentially depends on physical properties of dough and ranges between 250-550 cm³/100g of dough. In wheat flour gas-holding capacity is caused by the number and quality of gluten that forms elastic and flexible frame in the dough.

Gluten is a protein complex that can form stable highly developed thin-walled spongy structure under the influence of carbon dioxide evolved during fermentation. In pores of this structure a large number of gases is kept loosening the dough well. The more flour contains gluten of good quality, the higher gas-holding capacity of flour is. Therefore, indicator of gluten content and its quality can be used to predict gas-holding capacity.

Water absorption ability characterizes potential of protein molecules absorb moisture. However, for flour of spelt grain there are almost no data on peculiarities of gas-holding and water absorption capacities that determines the relevance of this study.

Gluten content in spelt grain varied significantly depending on the variety. Thus, its content was the highest of the variety Zoria of Ukraine – 46,4 % which corresponded to a very high level. Gluten content corresponded to this level in grain of varieties Schwabenkorn, Australian 1 but it was lower and amounted to 36,4–38,4 %.

In lines LPP 1305, LPP 3132, LPP 1224 gluten content corresponded to the average level – 27,9–33,9 %.

Results of the studies found that the indicator of gas-holding capacity of flour was changing significantly depending on the variety and length of fermentation. This indicator reaches the greatest value after 90-minute fermentation. The most value was in flour of the variety Zoria of Ukraine – 575 cm³, in flour of the rest of varieties this indicator was significantly lower and amounted to 420–451 cm³ which was 21–27 % less compared to the standard. The lowest value of gas-holding capacity was after 30 minutes of dough fermenting – 120–224 cm³ depending on the variety. With the continuation of the fermentation duration gas-holding capacity of flour decreased but varied depending on the variety like tendency of 90-minute fermentation.

According to levels-parameters of P.M. Zhukovsky a very high gas-holding capacity of flour is from the dough of the variety Zoria of Ukraine, flour of varieties Schwabenkorn, Australian 1, LPP 1305 and LPP 1224 is characterized by the high indicator and in flour of remaining varieties this indicator was average.

In the process of fermenting dough stability varied depending on the variety. Thus, in flour of varieties Zoria of Ukraine, Schwabenkorn and LPP 1305 gas-holding capacity decreased from 445–575 cm³ during 90-minute fermentation to 358–400 cm³ after 120 minutes of fermentation, whereas in the rest of varieties this indicator decreased to 250–305 cm³ or by 24–37 % compared to standard.

Correlation analysis results between gluten content in grain and gas-holding capacity of flour based on the length of dough fermentation indicate that a very high relationship between indicators is determined after dough fermentation for 60 and 90 minutes.

Water absorption capacity of spelt grain flour varied from 44,9 to 56,5 % depending on the variety. All varieties except line LPP 1224 exceeded the standard by 3–23 % in which this indicator was 46 %.

The highest water absorption capacity was in grain of the variety Australian 1 – 56,5 % and the lowest one was of line LPP 1224 – 44, 9 %.

So, as a result of studies it is found that gas-holding capacity of dough from spelt flour and its stability during fermentation essentially depends on gluten content in grain defined by peculiarities of the variety. The highest indicator of gas-holding capacity is determined for flour of spelt grain of varieties Zoria of Ukraine, Schwabenkorn and Australian 1 after 90-minute dough fermentation.

Key words: spelt, gluten, gas-holding, water absorption capacity, variety.