The thesis is devoted to the improvement and scientific substantiation technology bread using sourdough starter spontaneous fermentation from flour grain crops (buckwheat, oatmeal and rice).
The technological properties the flour of cereal crops were investigated. It was found that green buckwheat, oat, and rice flours are characterized by a larger particle size and lower activity of proteolytic and amylolytic enzymes. At the same time, cereal flours have starch grain sizes that are 15.8-40.0 % smaller than first- grade wheat flour (control), as well as a lower temperature at which starch gelling begins and a higher viscosity suspension. The water absorption capacity was 50 % higher in oat flour, 10.7 % higher in rice flour, and 10.3 % lower in green buckwheat flour compared the control. The protein fractional composition in buckwheat flour is dominated by albumin (60.5 %), oat flour by globulins (44.0 %), whereas in wheat and rice flour the glutelin fraction prevails.
The study revealed that buckwheat and oatmeal flour contain more intrinsic sugars, ensuring more intense gas formation at the beginning fermentation. But lower sugar-forming capacity and autolytic activity lead to a decrease in the intensity by 1 .4-2.7 times compared to wheat flour.
The possibility using cereal flour as a nutrient medium for spontaneous fermentation starter cultures is studied further. Using mathematical and statistical modeling, the optimal conditions for the starter cultivation cycle were determined: mass fraction is 52 % for rice starter, 60 % for buckwheat starter, and 70 % for oatmeal starter; fermentation temperature for all starter cultures is 28 °C; fermentation duration for rice and buckwheat starter is 120 h., and for oatmeal starter is 96 h. High quality starter cultures are ensured under the following conditions the production cycle: the amount a ripe starter is 50 % for rice starter, 35 % for buckwheat and oatmeal starter, fermentation temperature for all starter cultures is 28 °C, fermentation duration for rice starter is 12 h, for buckwheat and oatmeal starter is 14 hours. It was found that the preservation of the studied starter cultures by adding salt and cooling is effective for the discrete mode of operation of enterprises. The acidity of all s ples of starter cultures decreases slightly after 21 days storage - by 1.2-2.4 degrees.It has been established that the optimal storage period for cooling preservation is: rice starter - no more than 14 days, buckwheat and oatmeal – no more than 21 days. Salt application was most effectively used for rice sourdough, as its quality indicators were best preserved by this method. Thus, the acidity decreased by 15.9%, and the activity of lactic acid bacteria by 30 %.
Using the method described above, it was found that in wheat flour bread technology, the appropriate dosage for oat and buckwheat starter is 15% by weight of flour; in bread technology made from a mixture or wheat and rye flour, 30% by weight in flour; and in gluten-free bread technology, 30% rice or 20% buckwheat starter by weight in starch and flour mixture. It has been shown that increasing the dosage of sourdough starter in wheat, wheat-rye, and gluten-free bread formulations intensifies dough maturation, as evidenced by an increase in the lifting power and duration as well as the dough proofing, improves acid accumulation and carbon dioxide release. It was found that the visco-plastic characteristics wheat and wheat-rye breads deteriorated with the increase in cereal sourdough dosage due to a decrease in wheat flour content as well as gluten in the recipe. This confirms the need to adjust recipes to include cereal and structure-forming additives. However, it has been found that creating an acidic environment in wheat dough by adding 15% oat and buckwheat sourdoughs strengthens gluten, which will positively affect the quality of finished products. In gluten-free dough, gas retention improves with an increase in the percentage of sourdough starter.
The expediency that buckwheat and oat flakes and dry wheat gluten should be included in the recipes for wheat and wheat-rye bread using spontaneously fermented sourdough starter flours from cereal flour was demonstrated. These ingredients improve the consumer properties a bread, as evidenced by the growth of a complex quality indicator. The amount of protein increased by 1.1 times in wheat bread, dietary fiber by 1.3 times, and by 1.25 and 1.4 times in wheat-rye bread, respectively. Green buckwheat flour added to gluten-free bread increases the protein content by 2.2 times, dietary fiber by 2.0 times, and vitamins B9, PP and E by 7.2 times, 7 times and 5 times, respectively. Thus, the selected recipes allowed to reduce staling, as evidenced by the indicators friability and water absorption capacity crumb, as well as deformation crumb, determined by the penetrometer.
