RESEARCH ON THE PRODUCTION OF FUNCTIONAL BREAD AND PASTRY PRODUCTS USING WINEMAKING BY-PRODUCTS

Анотація

The object of the research is dietary fibers obtained from winemaking by-products and the technology for producing functional bread using these materials. Although a number of studies have been conducted on resource-saving technologies in winemaking, the use of winemaking by-products in bread production has not been sufficiently investigated. The results showed that the total content of phenolic compounds in pomace obtained from the Rkatsiteli variety was 4.1 g/kg, while in Isabella it was 9.6 g/kg, and in the Madrasa variety it was significantly higher, reaching 21.4 g/kg. The content of polysaccharides was lowest in the Madrasa samples and highest in Rkatsiteli, with Isabella occupying an intermediate position. In the grape skin, easily hydrolysable fractions (pectic substances and hemicelluloses) of the Rkatsiteli variety were mainly represented by L-arabinose (6.2 mg/100 g), D-xylose (4.4 mg/100 g), D-galacturonic acid (3.1 mg/100 g), and D-glucose (2.1 mg/100 g). In the Madrasa variety, these fractions exhibited a somewhat different profile, being represented by D-glucose (9.9 mg/100 g), D-galactose (5.4 mg/100 g), D-xylose (4.5 mg/100 g), L-arabinose (4.3 mg/100 g), and other components. Among the hardly hydrolysable fractions in the Rkatsiteli variety, D-glucose (10.3 mg/100 g), D-mannose (5.9 mg/100 g), D-xylose (5.7 mg/100 g), and D-galacturonic acid (3.6 mg/100 g) predominated. In the Madrasa grape variety, the hardly hydrolysable fractions were represented by the same compounds, but their contents were somewhat lower. The mineral content of the pomace was found to be 2.6–2.7%. Compared to fresh pomace, fermented pomace showed a decrease in tartrate content by 0.7–2.5% and phenolic compounds by 20–30%. The content of pectic substances ranged from 2.5–3.5% in seeds and 2.7–5.8% in skins, with higher values observed in the Samukh and Shamkir samples and relatively lower values in the Goygol samples. The highest pectin content in grape skins was recorded in Shamkir, while the lowest was observed in Goygol. Grape skin, seed, and stem additives were incorporated into the dough at a level of 3%. The addition of grape seeds increased the β-carotene content from 1.4 mg/% to 7.9 mg/%, while the vitamin C content decreased slightly from 5.8 mg to 5.6 mg. A multiple increase in zinc content was observed, accompanied by a decrease in macroelements and calcium, while an improvement in organoleptic quality was noted.