Search

The current study aimed to investigate exopolysaccharides (EPSs) produced by two Antarctic yeasts isolated from soil and penguin feathers samples collected on Livingston Island (Antarctica). The strains were identified as belonging to the species Leucosporidium yakuticum (LY) and Cystobasidium ongulense (CO) based on molecular genetic analysis. The EPS production was investigated using submerged cultivation. Different chemical, chromatographic, and spectral analyses were employed to characterize EPSs. LY accumulated 5.5 g/L biomass and 4.0 g/L EPS after 120 h of cultivation, while CO synthesized 2.1 g/L EPS at the end of cultivation, and the biomass amount reached 5.5 g/L. LY-EPS was characterized by a higher total carbohydrate content (80%) and a lower protein content (18%) by comparison with CO-EPS (62%, 30%). The LY-EPS mainly consisted of mannose (90 mol%), whereas CO-EPS had also glucose, galactose, and small amounts of uronic acids (8–5 mol%). Spectral analyses (FT-IR and 1D, 2D NMR) revealed that LY-EPS comprised a typical β-(1 → 4)-mannan. Branched (hetero)mannan, together with β/α-glucans constituted the majority of CO-EPS. Unlike LY-EPS, which had a high percentage of high molecular weight populations, CO-EPS displayed a large quantity of lower molecular weight fractions and a higher degree of heterogeneity. LY-EPS (100 ng/mL) elevated significantly interferon gamma (IFN-γ) production in splenic murine macrophages and natural killer (NK) cells. The results indicated that newly identified EPSs might affect IFN-γ signaling and in turn, might enhance anti-infectious responses. The data obtained also revealed the potential of EPSs and yeasts for practical application in biochemical engineering and biotechnology. [ABSTRACT FROM AUTHOR]

In this study, rosehip tea and two rosehip‐containing blends, along with their infusions and decoctions, were investigated. The first blend contained hibiscus and rosehip, while the second one was a mixture of rosehip, apple, pear, and St. John's wort. It was established that the carbohydrates were a major constituent in all samples. However, the highest protein, ash, and uronic acids content were detected in a hibiscus‐containing blend. The rosehip material exhibited the highest lipid content, while higher levels of natural pigments were determined in St. John's wort‐containing blend. The uronic acids and fructose were the major components in the rosehip extracts, while sucrose and organic acids (malic, quinic, neochlorogenic, chlorogenic acid) predominated in the hibiscus‐containing extracts. Infusions exhibited higher phenolic acid content and antioxidant activity than the decoctions. However, the decoction could be preferred as method of extraction regarding polysaccharide accumulation. Both extracts had a very low caloric value. Practical applications: The results of the current study would provoke tea companies and producers to take interest in the design of a new herbal blend with modified composition and improved health benefits through a small amount of easily extractable polysaccharide‐rich herbal material. They may also recommend another appropriate method for consumers to improve the extraction of significant bioactive substances. In addition, the different forms of the water extracts, obtained from rosehip‐based tea blends, could be used directly or after proper processing as ingredients in food supplements. [ABSTRACT FROM AUTHOR]

Increasing interest in edible flowers referred on their continuously growing consumption. Extracts of bioactive substances by solvents were the most common method for the processed edible flowers. However, most of the reports deal with ethanol or methanol extracts. Information about the bioactive compounds in water and acetone extracts are limited. Moreover, some reports presented values for fresh weight, while bioavaillability of dry extracts and their antioxidant potential were not discussed in details. Therefore, the object of the current study was to evaluate the content of the bioactive compounds and in vitro antioxidant activity of water and acetone extracts obtained from pomegranate (Punica granatum) and orange trees (Citrus aurantium) edible flowers. The commercial available flowers of pomegranate and orange trees were extracted with water and acetone in an ultrasonic bath. The extracts of edible flowers were analyzed for: carbohydrates (sugars and uronic acids), total chlorophylls, total carotenoids, total phenols, total flavonoids, anthocyanidins. Antioxidant activity was evaluated by four reliable methods (2,2-diphenyl- 1-picrylhydrazyl - DPPH, 2,2'-azino-bis-3-ethylbenzthiazoline- 6-sulphonic acid - ABTS, ferric reducing antioxidant power - FRAP and cupric reducing antioxidant capacity assays - CUPRAC). Orange trees (Citrus aurantium) water extract and acetone extracts from pomegranate (Punica granatum) were obtained in the highest yields. Carbohydrates dominated in orange flowers extracts. Sucrose, glucose and fructose were detected in water extracts of edible flowers. Total chlorophylls, carotenoids, flavonoids and anthocyanidins dominated in acetone extracts from pomegranate. However, water extract of pomegranate contained the highest level of total phenolic compounds 230.8 ± 9.5 mg GAE/g extract. Due to the high total phenolic content, the water extracts of pomegranate demonstrated well pronounced antioxidant activity. The acetone and water extracts from pomegranate (Punica granatum) and orange trees (Citrus aurantium) edible flowers were evaluated as sources of antioxidants. The results reveal the potential application of the obtained edible flower extracts as additives in food and cosmetics. [ABSTRACT FROM AUTHOR]

Background. Common whitebeam, Sorbus aria (L.) Crantz is an European and Near-Eastern deciduous tree with small red fruits. However, the edible use of this forest fruit is currently not widespread. Also, its nutritional and antioxidative properties remained undiscovered. In this study, the chemical composition and antioxidant properties of common whitebeam fruit were investigated. Materials and methods. The fruit were collected from Golo Bardo Mountain in Bulgaria. The phytochemical (carotenoids, phenolic compounds, flavonoids), nutritional (moisture, ash, titrable acidity, lipids, proteins, pectin, carbohydrates) and antioxidant activity were evaluated by four assays (DPPH, ABTS, FRAP, and CUPRAC). Results. Sugar analysis demonstrated that only fructose and glucose were detected in the fruit. Pectin content did not exceed 1.30%. Moreover, the fruit had a low lipid content (0.80%). The whitebeam fruit were also characterized as a source of carotenoids (1.69 mg/100 g fresh weight, fw), phenolic compounds (32.42 mg GAE/100 g fw), and flavonoids (20.08 mg QE/100 g fw). Among phenolic acids, only 2,4-dihydrohybenzoic, caffeic, p-coumaric, and sinapic acid were detected. The antioxidant potential of the fruit was from 168.52 mM TE/100 g fw (FRAP) to 244.81 mM TE/100 g fw (CUPRAC assay). Conclusion. The current research enriched the available information about the nutritional potential and chemical composition of common whitebeam fruit and their low sugar content. The absence of sucrose, together with its high phenolic content, demonstrated the potential of this fruit for future application in food products and supplements. [ABSTRACT FROM AUTHOR]

Black chokeberry (Aronia melanocarpa) fruits are among the richest sources of polyphenols and anthocyanins in plant kingdom and suitable raw material for production of functional foods. The popularity of chokeberries is not only due to their nutritional value but also to the constantly emerging evidence for their health-promoting effects. The current study presents detailed information about the content and composition of sugars, organic acids, and polyphenols in 23 aronia samples grown under the climatic conditions of Bulgaria, in 2016 and 2017. Sorbitol was found to be the main carbohydrate of fresh aronia fruits. Its content was in the range 6.5–13 g/100 g fresh weight (FW), representing 61%–68% of low-molecular-weight carbohydrates. Organic acids were represented by substantial amounts of quinic acid (average content 404.4 mg/100 g FW), malic acid (328.1 mg/100 g FW), and ascorbic acid (65.2 mg/100 g FW). Shikimic acid, citric acid, oxalic acid, and succinic acid were found as minor components. Chokeberries were particularly rich in proanthocyanidins, anthocyanins, and hydroxycinnamic acids. The total polyphenol content of aronia fruits varied between 1022 mg/100 g FW and 1795 mg/100 g FW and ORAC antioxidant activity from 109 µmol TE/g to 191 µmol TE/g FW. We also investigated the relationship between the chemical composition of berries and chemical compositions and antioxidant activity of aronia functional drinks—juices and nectars. The differences in the chemical composition of the fruits resulted in functional foods that differ significantly in their chemical composition and antioxidant activity. Additionally, we demonstrated that temperature of juice pressing and nectar extraction has a profound effect on the polyphenol content and composition of these products. This is very important since differences in the chemical composition of raw chokeberries and variation of technological parameters during processing could result in functional foods with different chemical composition, rendering different biological activity. [ABSTRACT FROM AUTHOR]