1,720,992 research outputs found
Flavonoid Occurrence, Bioavailability, Metabolism, and Protective Effects in Humans: Focus on Flavan-3-ols and Flavonols
No full textFlavonoids are profusely abundant in the human diet and might be responsible for the advantages ascribed to dietary regimens rich in plant foods. Notwithstanding the evidence from epidemiological and cohort studies, an unambiguous and exhaustive pattern has not yet emerged regarding the mechanisms underlying their food-related health properties. It is now increasingly evident that the sole direct action of substances available in planta is not sufficient to fully explain the benefits of polyphenol-rich dietary habits. To elucidate this conundrum, a better comprehension of the interplay between human and microbial metabolism and dietary polyphenols is needed. This chapter provides a detailed overview of the current knowledge on bioavailability and in vivo biotransformation of two widespread classes of flavonoids: flavonols and flavan-3-ols. According to data collected, these substances are not always endowed with the highest bioactivities in vivo, and a deeper knowledge of their metabolites is needed to properly assess their overall contribution to human health and to single out substances to be monitored for the exhaustive profiling of flavonoid bioavailability
(Poly)phenolic content and profile and antioxidant capacity of whole-grain cookies are better estimated by simulated digestion than chemical extraction
Full text linkIt is widely recognized that the biological effects of phytochemicals cannot be attributed to the native compounds present in foods but rather to their metabolites endogenously released after intake. Bioavailability depends on bioaccessibility, which is the amount of the food constituent that is released from the matrix in the gastrointestinal tract. The use of chemical extraction to evaluate the content and profile of phytochemicals does not mirror the physiological situation in vivo, and their bioaccessibility should be considered while assessing their nutritional significance in human health. The current study was designed to compare the (poly)phenolic profile and content and antioxidant capacity of whole-grain (WG) cookies using chemical extraction and a more physiological approach based on simulated digestion. Three types of organic WG cookies (made with durum, Italian khorasan, or KAMUT® khorasan wheat) were considered, either fermented by Saccharomyces Cerevisiae or sourdough. Although the flour type and the fermentation process influenced the release of phytochemicals from the cookie matrix, in almost all samples, the simulated digestion appeared the most efficient procedure. Our results indicate that the use of chemical extraction for evaluation of the phytochemicals content and antioxidant capacity of food could lead to underestimation and underline the need for more physiological extraction methods
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Optimized Enzymatic Extraction of Phenolic Compounds from Verbascum nigrum L.: A Sustainable Approach for Enhanced Extraction of Bioactive Compounds
No full textVerbascum nigrum, commonly known as black mullein, is widely used in traditional medicine for its expectorant, mucolytic, sedative, and diuretic properties. This study aimed to develop and optimize a standardized method for extracting phenolic compounds from V. nigrum using enzymatic pretreatment followed by solvent extraction. Enzymatic treatment does not rely on harmful solvents and is a low energy-intensive process, making it a suitable green technology for the food, cosmetic, and pharmaceutical industries. The research explored the use of different lignocellulolytic enzymes, including pectinase, cellulase, α-amylase, and xylanase, to break down plant cell walls, enhancing the release and bioaccessibility of active compounds. The two-step extraction process proposed combined enzymatic pretreatment and hydroalcoholic extraction, resulting in a considerably improved yield of phenolic compounds (24 mg/g DM). Analytical characterization using a high-performance liquid chromatography (HPLC) system coupled with a diode-array-detector (DAD) and ultra-high-performance liquid chromatography (UHPLC) coupled with DAD and tandem mass spectrometry (MS/MS) revealed a higher concentration of target bioactive compounds in enzymatically treated extracts compared to traditional methods, including phenolic derivatives (e.g., caffeic acid, p-coumaric acid, and verbascoside), and flavonoids (e.g., luteolin). Up to 22 phenolic and flavonoid compounds were characterized. This study provides new insight into the potential of enzymatic extraction as a green and efficient alternative to conventional extraction methods, for the production of high-quality herbal products richer in (poly)phenolic compounds, highlighting its potential for industrial applications
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Phytochemical profiling of volatile and bioactive compounds in yellow mustard (Sinapis alba) and oriental mustard (Brassica juncea) seed flour and bran
Full text linkThe impact of processing on the phenolic acids, free betaine and choline in Triticum spp. L. whole grains and milling by-products
Full text linkWheat (Triticum spp. L.) is an important source of nutrients and bioactive compounds with recognized beneficial effects. Wheat undergoes several processes with the final aim of separating the endosperm from the outer layers, usually discarded. In this study, free and bound phenolic acids (PAs) profile, betaine and choline contents were quantified in six different wheat species (durum and bread wheat, turanicum wheat, einkorn, emmer and spelt), the corresponding milling by-products (bran, middlings, aleurone and I, II and III steps of debranning) and flour/semolina, using UHPLC-MS/MS methods. The bound form of phenolics was the component present in higher concentration (80% of the total, in average) and ferulic acid was the most abundant compounds, representing between 67 and 73 % of total PAs. Among the species, bread wheat grain totalized the highest content of total PAs (1209.31 ± 7.3 μg g−1 d.w.). Betaine and choline are abundantly present in wheat species. In general, the highest content of bioactive compounds was found in bran (3 times higher than whole grains), emphasizing the good nutritional profile of these by-products. The milling process leads to a severe reduction of phenolic acids and methyl-donors in the end-products
- …
