Chemical Characteristics and Antioxidant Activity of Arctostaphylos uva-ursi L. Spreng. at the Southern Border of the Geographical Range of the Species in Europe

The bearberry (Arctostaphylos uva-ursi L. Spreng.) is a source of herbal material—bearberry leaf (Uvae ursi folium), which is highly valued and sought by pharmaceutical and cosmetic industries. For many years, leaves of this plant have been used in traditional medicine as a diuretic, antimicrobial, and anti-inflammatory agent for various diseases of the urogenital tract. The bearberry has also been proposed as a natural antioxidant additive due to the high contents of phenolic compounds in its leaves. The study was focused on characterization of the basic phytochemical composition and antioxidant activity of extracts derived from bearberry leaves collected from plants located at the southern border of the geographical range of the species in Europe. The investigated herbal material is characterized by a different chemical profile compared to the chemical profiles of bearberry found in other parts of the continent. Bearberry extracts from plants growing in two different habitat types—heathlands and pine forests showed a wide range of variation, especially in the concentration of hyperoside, corilagin, and methylartutin and the total flavonoid contents. In addition to arbutin, bearberry can be a valuable source of phenolic compounds, which are mainly responsible for the antioxidant properties of extracts. The high content of phenols and high values of antioxidant parameters indicate a high potential of bearberry leaves to be used as a powerful natural source of antioxidants in herbal preparations. Therefore, the A. uva-ursi populations can be a source of plant material for pharmaceutical, cosmetic, and food industries.

Bioprospecting brown algae (Sargassum polycystum C. Agardh) as a potential antioxidant additive in snack bar and its sensory evaluation

Fucoxanthin from brown algae has potential as a promising functional food component. However, fucoxanthin is less stable under high temperature and light exposure. The purpose of this study was to analyse the effect of stevia and cacao butter in increasing the stability of Sargassum polycystum C. Agardh extract containing fucoxanthin and its application as a snack bar. Brown algae, S. polycystum, was extracted using 96% foodgrade ethanol. Antioxidant activity and stability assay were performed using the 2,2- Diphenyl-1-Picrylhydrazyl (DPPH) method. Antioxidant activity of both, extract (E) and extract + stevia (ES), was found to decrease with time. Meanwhile, cacao butter was able to maintain extract’s stability without any significant difference when compared to extract alone. A combination of extract, stevia, and cacao butter (ESC) were found to be able to maintain antioxidant stability. Formulation of a snack bar with cacao butter and 1% stevia were more preferred by the panellists when compared to the other formulations. This study reports that cacao butter and 1% stevia is able to maintain antioxidant stability and improve the economic value of S. polycystum, one of them through the formulations of the snack bar.

Influence of Solvents on the Antioxidant Properties of the Birch Outer Bark Extract in Cosmetic Emulsions

The goal of this study was to evaluate the influence of birch outer bark (BOB) extraction solvents on the antioxidant properties of the obtained dry extracts, which were added in cosmetic product emulsions. Extracts obtained in ethanol, 2-propanol, 1-butanol and ethyl acetate as well as one purified in ethanol by means of recrystallization were used as antioxidant additives, in 30 and 60 mg·g-1 concentrations, to cosmetic water-in-oil type emulsions. It was found that raw extracts had a considerably higher antioxidant stability than purified ones, because the raw extracts showed a higher phenolic compound content. The highest stability was detected in the cosmetic sample, which had a raw BOB extract obtained in 2-propanol. At the additive concentration of 60 mg·g-1, the protection factor was 20.6 times higher than in the case of a blank sample. Among other solvents used, 2-propanol showed the best solubility for BOB extract phenolic compounds, the content of which reached 3.58 wt% from the oven dry extract. It could be concluded that raw BOB extracts act as an excellent antioxidant additive in cosmetic emulsions.

Lignin/Carbohydrate Complex Isolated from Posidonia oceanica Sea Balls (Egagropili): Characterization and Antioxidant Reinforcement of Protein-Based Films

A lignin fraction (LF) was extracted from the sea balls of Posidonia oceanica (egagropili) and extensively dialyzed and characterized by FT-IR and NMR analyses. LF resulted water soluble and exhibited a brownish-to-black color with the highest absorbance in the range of 250–400 nm, attributed to the chromophore functional groups present in the phenylpropane-based polymer. LF high-performance size exclusion chromatography analysis showed a highly represented (98.77%) species of 34.75 kDa molecular weight with a polydispersity index of 1.10 and an intrinsic viscosity of 0.15. Quantitative analysis of carbohydrates indicated that they represented 28.3% of the dry weight of the untreated egagropili fibers and 72.5% of that of LF. In particular, eight different monosaccharides were detected (fucose, arabinose, rhamnose, galactose, glucose, xylose, glucosamine and glucuronic acid), glucuronic acid (46.6%) and rhamnose (29.6%) being the most present monosaccharides in the LF. Almost all the phenol content of LF (113.85 ± 5.87 mg gallic acid eq/g of extract) was water soluble, whereas around 22% of it consisted of flavonoids and only 10% of the flavonoids consisted of anthocyanins. Therefore, LF isolated from egagropili lignocellulosic material could be defined as a water-soluble lignin/carbohydrate complex (LCC) formed by a phenol polymeric chain covalently bound to hemicellulose fragments. LCC exhibited a remarkable antioxidant activity that remained quite stable during 6 months and could be easily incorporated into a protein-based film and released from the latter overtime. These findings suggest egagropili LCC as a suitable candidate as an antioxidant additive for the reinforcement of packaging of foods with high susceptibility to be deteriorated in aerobic conditions.

Impact of Tetrapeptide-FSEY on Oxidative and Physical Stability of Hazelnut Oil-In-Water Emulsion

This study investigates the antioxidant behaviors of a hazelnut tetrapeptide, FSEY (Phe-Ser-Glu-Tyr), in an oil-in-water emulsion. The emulsion was prepared with stripped hazelnut oil at a ratio of 10%. O/W emulsions, both with and without antioxidants (FSEY and TBHQ), were incubated at 37 °C. The chemical stabilities, including those of free radicals and primary and secondary oxidation productions, along with the physical stabilities, which include particle size, zeta-potential, color, pH, and ΔBS, were analyzed. Consequently, FSEY displayed excellent antioxidant behaviors in the test system by scavenging free lipid radicals. Both primary and secondary oxidation products were significantly lower in the FSEY groups. Furthermore, FSEY assisted in stabilizing the physical structure of the emulsion. This antioxidant could inhibit the increase in particle size, prevent the formation of creaming, and stabilize the original color and pH of the emulsion. Consequently, FSEY may be an effective antioxidant additive to use in emulsion systems.