The work focuses on the use whole and crushed of seeds of high-linolenic yellow-seed varieties of flax seeds "Zolotystyi" and "Svitlozir" in the production of bakery products in order to enrich the products with physiological and functional substances. "Zolotystyi" and "Svitlozir" are varieties of flax with white-flowered genotype (white flax).
It has been proven that flax seeds of these varieties due to the high content of α-linolenic acid, water-soluble polysaccharides, vitamin E and complete amino acid proteins can improve the composition of bakery products and give it functional properties.
It is recommended to dose whole seeds up to 15% by weight of flour, crushed flax seeds - up to 20% by weight of flour.
To enrich wheat bread with crushedflax seeds, it is advisable to use thecrushed seeds size of the particles that have passed through sieve the size of the cells 1 mm. This affects the water-absorbing ability of the dough, so it is recommended to increase the humidity of the dough with crushed flax seedsby 1%. Reducing the size of crushed flax seeds has a negative effect on the quality of the crumb of the products.
It is noted that crushed flax seeds can be used in the recipe of puff pastry products. At the same time, the dosage of crushed flax seeds in the amount of 15% by weight of flour allows not only to increase the nutritional value of the products, but also to reduce the prescribed amount of margarine per layer.
It has been proven that the application of technological measures helps to improve the quality of products with flax seeds. It was found that the production of products on sponge mixing methodwith the addition of flax seeds in to the first phase leads to an increasing in the specific volume of products by 24 and 29%, respectively, compared to products, in which seeds are added to the dough.
Еhe optimal modes of dough kneading with whole and crushed flax seeds were studied. The optimal duration of kneading the dough with whole seeds is 5 min at first speed and 15 min at second speed. The optimal mode of kneading the dough with the addition of crushed flax seeds is 5 min at the first speed and up to 10 min at the second speed.
The effectiveness of the operation of pre-soaking whole and crushed flax seeds to improve the quality of bread has been proven. Optimization of the technological process revealed that when using whole and crushed flax seeds in the production of wheat bread, it is advisable to use the soaking operation on the following parameters: ratio of flax seeds and water 1: 2 or 1: 3, water temperature for soaking 60°C, pre-soaking duration 90…120 min.
It was suggested that water-soluble polysaccharides of flax seeds, in the case of pre-soaking the seeds during kneading the dough form protein-polysaccharide complexes, changing the protein composition of the dough. This is confirmed by an increasing in samples with soaking of proteins of lower molecular weight by 60% (for whole) and 49% (for crushed) compared to samples without pre-soaking. When soaking both whole and ground flax seeds, the amount of gluten is reduced by 32% and 45% compared to the corresponding samples without soaking.
The use of soaking both whole and crushed seeds causes a significant reduction in the duration of the formation of wheat dough.
The results of research have shown that the addition of whole and crushed flax seeds has a significant effect on the dynamics of carbon dioxide releasing and changes in the nature of the dynamics of carbon dioxide releasing.
In particular, enrichment of the liquid phase of wheat dough with solutions of flax polysaccharides, water-soluble protein substances promotes more intensive release of carbon dioxide and changes the nature of the dynamics of carbon dioxide release in one-stage fermentation for samples with crushed dry and pre-soaked and dryflax seeds.
It is recommended to reduce the fermentation time for the sample with whole seeds to 90 minutes, and for samples with crushed and pre-soaked flax products to 60 minutes.
It was noted that the addition of flax seeds increases the viscosity of the system, which causes a slower heating of the layers of wheat dough during baking and prolongs the baking time by3…6 minutes compared to the control.
Gravimetric analysis has shown that bread with soaked flax seeds increases the content of bound moisture, reduces the retrogradation of starch, due to slowing formation of associations with amylose and amylopectin of gelatinized starch under the action of the slime-forming flax polysaccharides, which slows down the hardening process.
Based on the results of research, recipes and technological instructions for new bakery products have been developed such us «Lonok» bread, «Buterbrodnyi» bread, «Lliana» bun which contain high-linolenic yellow-seed flax varieties in whole and crushed form.
Key words: bread, flax seeds, α-linolenic acid, wheat dough, gluten, soaking, crumb microstructure, bakery products, staling.
