| Abstract [eng] |
Sea buckthorn berry pomace, which consists of seeds, skin and pulp residues, has a unique composition of nutrients and bioactive components. They include valuable lipids, proteins, dietary fiber and phenolic compounds which have antioxidant activity and can be beneficial to human health. At present, the pomace that is generated during berry processing is used inefficiently or even discarded, resulting in the loss of a lot of valuable raw material that could be used in the development of functional foods, food supplements, cosmetics and other purposes. The aim of this work is to apply a high-pressure extraction-based biorefining process for the fractionation of sea buckthorn (Hippophae rhamnoides L.) berry pomace in order to extract their functional components, and to evaluate their use for increasing the nutritional value of bread. The pomace seeds were separated from the other parts and ground. The highest mean of particle size distribution by surface area was found in buckthorn skins crushed through a 0.5 mm sieve (224 ± 9 μm), and the highest particle size distribution by volume was found in seeds (553 ± 40 μm) and skins (546 ± 30 μm) crushed through a 0,5 mm sieve. The ground fractions were extracted with supercritical carbon dioxide to give 10.73%, 14.67% and 10.35% of the extract from the pulp, seeds and skins, respectively. The cuticle extract had the highest antioxidant activity: ABTS•+ binding capacity - 52.2 ± 0.7 mg trolox equivalents (TE)/g, oxygen radical absorption capacity (ORAC) - 59.1 ± 1.0 mg TE/g, total phenolic content (TPC) - 7.15 ± 0.04 mg gallic acid equivalents (GAE)/g). The defatted by supercritical CO2 pomace fractions were further extracted with polar solvents - ethanol and water. the highest yield was obtained for sea buckthorn skins 15.38%, and with ethanol and water the highest yield was obtained for pulp 16.29%. Of all ethanol extracts, the extract of pomace had the highest antioxidant activity (ABTS•+ - 253.2 ± 1.1 mg TE/g, ORAC - 331.6 ± 21.3 mg TE/g, TPC - 72.9 ± 1.7 mg TE/g) and using ethanol and water seed extract (ABTS•+ - 426.7 ± 0.6 mg TE / g, ORAC - 535.4 ± 24.8 mg TE / g, TPC - 131.5 ± 4.4 mg GAE / g extract). Defatted sea buckthorn berry pomace fractions were tested in the bread recipe by replacing part of the flour with them. The effect of such a change on bread volume, porosity, moisture, color, protein and mineral content, antioxidant properties was evaluated. It was found that when the dough was added to the dough, the final color of the bread darkened, the higher the concentration of the bread added, the darker the color of the baked bread. The added sea buckthorn pulp significantly changed the taste of the bread. Thus, research has shown that sea buckthorn berries have bioactive compounds, their composition determines the antioxidant and textural properties of bread, so sea buckthorn berries can be used to develop higher value-added products. |
