The aim of this study was to analyze in vitro biological activities as anti-oxidant, anti-α-amylase, anti-α-glucosidase, anti-lipase, and anti-lipoxygenase activity, relative to bioactive components (phenolic acids, flavonols, xanthophylls, carotenes, esterified carotenoids, tocopherols, tocotrienols, and fatty acids) and the basic chemical composition (sugars, organic acid, dry matter, soluble solid, pH, titratable acidity, ash, pectins, and vitamin C) of Hippophaë rhamnoides berries. Six sea buckthorn cultivars commonly grown in Poland were analyzed including Aromatnaja, Botaniczeskaja-Lubitelskaja, Józef, Luczistaja, Moskwiczka, and Podarok Sadu. Berries contained 1.34–2.87 g of sugars and 0.96–4.22 g of organic acids in 100 g fresh weight, 468.60–901.11 mg of phenolic compounds, and 46.61–508.57 mg of carotenoids in 100 g dry mass. The fatty acid profile was established: palmitic > palmitoleic > oleic and linoleic > stearic and linolenic acids. The highest anti-oxidant (34.68 mmol Trolox/100 g dry mass) and anti-α-amylase potential (IC₅₀ = 26.83 mg/mL) was determined in Aromatnaja, anti-α-glucosidase in Botaniczeskaja-Lubitelskaja (IC₅₀ = 41.78 mg/mL), anti-lipase in Moskwiczka and Aromatnaja (average IC₅₀ = 4.37 mg/mL), and anti-lipoxygenase in Aromatnaja and Podarok Sadu fruits (100% inhibition). The studied sea buckthorn berries may be a raw material for the development of functional foods and nutraceutical products rich in compounds with high biological activity.

Bioactive peptides derived from food have been increasingly popular due to their therapeutic properties. Of particular importance are peptides with a multidirectional activity that can be used in the treatment and prevention of diet-related diseases. This paper attempts to utilize a by-product of phospholipid extraction from egg yolk as a source of peptides with a broad spectrum of biological activity. In addition, in this research we used a non-commercial enzyme obtained from Asian pumpkin, which has not been sufficiently researched in terms of its ability to release biopeptides from food proteins. In the present study the biological properties of peptides, derived from egg-yolk protein by-products (YP) remaining after phospholipid extraction, and their four synthetic analogs were investigated with regard to their antioxidant (radical scavenging capacity, Fe²⁺ chelating effect, reducing power (FRAP)) and antidiabetic (α-glucosidase and DPP-IV inhibitory activities) properties. One of them, with the sequence LAPSLPGKPKPD, exhibited the highest antioxidant activity (free radical scavenging activity (6.03 μM Trolox_eq per mg protein); FRAP (296.07 μg Fe²⁺ per mg protein)). This peptide also revealed the strongest DPP-IV (361.5 μmol L⁻¹) and α-glucosidase (1065.6 μmol L⁻¹) inhibitory activities, a novel multifunctional effect for peptides from an egg-yolk hydrolysate.

Enzymatic hydrolysis led to improve functional properties and biological activity of protein by‐products, which can be further used as protein ingredients for food and feed applications. The effects of proteolytic enzyme modification of egg‐yolk protein preparation (YP) and white protein preparation (WP), obtained as the by‐products left during the course of lecithin, lysozyme, and cystatin isolation on their biological and functional properties, were evaluated by treating a commercial Neutrase. The antihypertensive and antioxidative properties of YP and WP hydrolysates were evaluated based on their angiotensin‐converting enzyme (ACE)‐inhibitory activity and radical scavenging (DPPH) capacity, ferric reducing power, and chelating of iron activity. The functionality of obtained hydrolysates was also determined. Neutrase caused a degree of hydrolysis (DH) of YP and WP by‐products: 27.6% and 20.9%, respectively. In each of them, mixture of peptides with different molecular masses were also observed. YP hydrolysate showed high levels of antioxidant activity. The scavenging capacity, ferric reducing power, and chelating capacity were observed at the level: 0.44 μmol/L Trolox mg⁻¹, 177.35 μg Fe²⁺ mg⁻¹, and 549.87 μg Fe²⁺ mg⁻¹, respectively. YP hydrolysate also exhibited significant ACE‐inhibitory activity, in which the level was 59.2 μg. Protein solubility was significantly improved as the DH increased. WP hydrolysate showed high water‐holding capacity of 43.2. This study indicated that YP and WP hydrolysates could be used in foods as natural antioxidants and functionality enhancers.

The aim of the study was to evaluate the effect of purified extract from Rosa spinosissima fruits on the quality characteristics and antioxidant properties of yoghurt. The extract, added to yoghurt at a concentration of 0.1% and 0.2%, contained high quantities of phenolic compounds and exhibited high antioxidant activity due to the presence of anthocyanins flavan-3-ols, flavonols and ellagitannins. Yoghurt physicochemical properties, microbiology and antioxidant properties were evaluated after 1, 7 and 14 days of storage at a temperature of 4 °C. The data revealed a positive influence of rose preparation on yoghurt’s microflora and on its other properties. The highest count of traditional yoghurt microflora was observed in samples with 0.2% of extract. Its addition had a positive effect on the yoghurts’ color, giving them a characteristic pink color of an intensity dependent on additive concentration. It also significantly affected the yoghurts’ antioxidant properties, which were stable during storage, as well as the content of the introduced phenolic compounds.

The aim of the research was the analysis of yoghurts enriched with blue honeysuckle berries dry polyphenolic extract and new preparation of resistant starch. The additives were introduced individually at concentration 0.1% (w/v) and in mixture at final concentration of 0.1 and 0.2% of both components. Yogurt microflora, pH, and its physicochemical and antioxidant properties were examined over 14 days of storage under refrigerated conditions. Studies showed that both substances can be successfully used in yoghurt production. Yoghurt microflora es. S. thermophilus and Lb. delbrueckii subsp. bulgaricus counts appeared to be higher in samples supplemented with these additives comparing to control yoghurt by 3–8%. More stimulating effect on their growth, especially on S. thermophilus, revealed resistant starch. Addition of this polysaccharide improved also the rheological properties of yogurts, which showed higher viscosity than samples produced without it. Addition of honeysuckle berries preparation significantly influenced the yogurts’ color, giving them deep purple color, and their antioxidant potential. During storage, contents of anthocyanin and iridoid compounds were decreasing, but antioxidant activity in the products remained stable.

The aim of the study was to obtain alginate oligosaccharides by using two degradation methods of sodium alginate (SA): with hydrochloric acid (G—guluronate, M—mannuronate and G + M fractions) and hydrogen peroxide (HAS—hydrolyzed SA), in order to assess and compare their biological activity and physico-chemical properties, with an attempt to produce gels from the obtained hydrolysates. The efficiency of each method was determined in order to select the fastest and most efficient process. The ferric ion reducing antioxidant power (FRAP), the ability to scavenge DPPH free radicals, rheological properties, Fourier Transformed Spectroscopy (FTIR) and the microbiological test against Escherichia coli and Staphylococcus aureus were performed. In order to check the functional properties of the obtained oligosaccharides, the texture profile analysis was assessed. The hydrolysis yield of acid SA depolymerization was 28.1% and from hydrogen peroxide SA, depolymerization was 87%. The FTIR analysis confirmed the degradation process by both tested methods in the fingerprint region. The highest ferric reducing antioxidant power was noted for HSA (34.7 µg), and the highest hydroxyl radical scavenging activity was obtained by G fraction (346 µg/Trolox ml). The complete growth inhibition (OD = 0) of alginate hydrolysates was 1%. All tested samples presented pseudoplastic behavior, only HSA presented the ability to form gel.