| Abstract [eng] |
The aim of this work is to evaluate the use of sea buckthorn, blueberry and blackberry pomace after SFE - CO2 and blueberry extract in the development of functional bread and yogurt dessert products. Composition analysis of sea buckthorn, bilbeberry and blackberry pomace after SFE - CO2 was performed to determine the possible effects on foods. The highest antioxidant activity (ORAC - 65,91 ± 9,47 mg TE/g, ABTS • + - 262,09 ± 61,26 mg TE/g) and the highest content of phenolic compounds (29,05 ± 5,07 mg GAE/g ) was determined in bilberry pomace. High levels of dietary fiber (mainly in blackberry pomace) have also been found in berry by-products. When assessing the particle size, the smallest particles by volume were found in blackberry pomace (122,92 ± 10,07 μm), the largest - sea buckthorn pomace (416,63 ± 29,31 μm). During bread making process, 5% of the flour was replaced with different berry pomace and the quality of the products was assessed. Sea buckthorn pomace had the greatest positive effect on bread porosity, and was the only one to increase the porosity of the dough compared to the control bread. The results of the study can be attributed to the large particle size of the sea buckthorn pomace and little amount of fiber. These compositional features reduce the amount of retained water in dietary fiber. Compared to the control product, bread with blueberry pomace had the highest antioxidant activity and the highest content of phenolic compounds. Preliminary sensory analysis showed that blueberry bread is the most acceptable for evaluators, although the scientific literature often states that large color changes negatively affect consumer acceptability. Accelerated solvent extraction was used to obtain blueberry extract from the pomace after SFE - CO2. The yield was 50,44%. Ethanol extract was characterized by high antioxidant activity (ORAC – 127,55 ± 4,90 mg TE/g extract, ABTS•+ - 59,21 ± 0,67 mg TE/g extract) and high content of phenolic compounds (17,04 ± 0,09 mg GAE/g extract). The content of anthocyanins in blueberry extract was 125,3 ± 18,43 mg/100 g of extract, proanthocyanidins – 172,44 ± 2.43 mg/g of extract. A tendency to red and blue was observed in the color analysis of blueberry extract. Two types of yogurt were used for the production of yogurt desserts and the influence of blueberry extract on the products was determined. To improve yogurt desserts, different amounts of blueberry extract (0 g, 1 g, 2 g) were included. The change in color indices was first assessed. By increasing the amount of extract, darkening of the yogurt dessert, tendency to red color and a decrease in yellowness was observed. The extract also affected the pH of the product. As the amount of extract used increased in both formulations, the pH decreased. The amount of extract positively affected the texture parameters of yogurt - improved the firmness of the product. Thus, it can be concluded that the composition of berry pomace determines the properties of bread texture and antioxidant activity. Secondary raw materials with small particles and low content of dietary fiber have a positive effect on bread rheological properties. Increasing the amount of blueberry extract in yogurt desserts has a positive effect on texture strength and antioxidant activity. |
