1,721,102 research outputs found
Inhibition of lipid oxidation in soybean oil-in-water emulsions and bulk oil using acid hydrolyzed extracts of sugar beet leaves
No full textThis research investigated the effects of acid hydrolysis (AH) on phenolic extracts of sugar beet greens (SBG).
SBG extracts were acid hydrolyzed using 0.6 M HCl at 80 °C, and their total phenolic content (TPC), antioxidant activity, metal chelating activity, chlorophyll content and phenolic profile were monitored. The cupric chelating activity, TPC, and DPPH radical scavenging activity of extracts were significantly improved (p ≤ 0.05) after AH.
The chlorophyll content decreased significantly after AH. Moreover, AH disrupted the glycosidic link of phenolic compounds, causing concentrations of individual polyphenols to rise or the appearance of new phenolics such
as catechin, myricetin, etc. The extracts were added to soybean oil-in-water emulsions and bulk oil to inhibit lipid oxidation. The emulsion was prepared by adding 2% (w/v) stripped soybean oil and 0.2% (w/v) Tween 20 as a surfactant to a sodium acetate-imidazole buffer (10 mM, pH 7.0). The physical properties of the emulsions
were examined by assessing the distribution of droplet sizes and the zeta potential using a Zetasizer Nano-ZS apparatus. The oxidation stability of the emulsion was monitored by measuring the primary (hydroperoxide)
and secondary (hexanal) oxidation products. The Rancimat method was used to measure the oxidative stability of bulk soybean oil. The emulsion containing 400 μM TPC of the control extract had the longest lag phase in oxidative stability. However, the bulk oil containing 400 μM TPC of the acid-hydrolyzed extract had the highest
oxidative stability. Figure 1 shows the design of experiment of the project. The better effectiveness of acidhydrolyzed extract in the bulk suggests that the modified phenolic composition had a more favorable impact in this lipid environment
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
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Acid-hydrolyzed phenolic extract of parsley (Petroselinum crispum L.) leaves inhibits lipid oxidation in soybean oil-in-water emulsions
Full text linkThe antioxidant activity of the natural phenolic extracts is limited in particular food systems due to the existence of phenolic compounds in glycoside form. Acid hydrolysis post-treatment could be a tool to convert the glycosidic polyphenols in the extracts to aglycones. Therefore, this research investigated the effects of an acid hydrolysis post-treatment on the composition and antioxidant activity of parsley extracts obtained by an ultrasound-assisted extraction method to delay lipid oxidation in a real food system (i.e., soybean oil-in-water emulsion). Acid hydrolysis conditions were varied to maximize total phenolic content (TPC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. When extracts were exposed to 0.6 M HCl for 2 h at 80 °C, TPC was 716.92 ± 24.43 μmol gallic acid equivalent (GAE)/L, and DPPH radical scavenging activity was 66.89 ± 1.63 %. Not only did acid hydrolysis increase the concentrations of individual polyphenols, but it also resulted in the release of new phenolics such as myricetin and gallic acid. The extract's metal chelating and ferric-reducing activity increased significantly after acid hydrolysis. In soybean oil-in-water emulsion containing a TPC of 400 μmol GAE/L, the acid-hydrolyzed extract had an 11-day lag phase for headspace hexanal compared to the 6-day lag phase of unhydrolyzed extract. The findings indicated that the conversion of glycosidic polyphenols to aglycones in phenolic extracts can help extend the shelf-life of emulsion-based foods
Antioxidant and prooxidant activity of acid-hydrolyzed phenolic extracts of sugar beet leaves in oil-in-water emulsions
Full text linkThis study aimed to enhance the oxidative stability of soybean oil-in-water
emulsions using acid-hydrolyzed and unhydrolyzed extracts obtained from
sugar beet leaves. The optimum extraction process, which includes 8 min of
ultrasonication followed by a 2-h acid hydrolysis, released new phenolics
(e.g., catechin, myricetin, etc.) and increased the total phenolic content (TPC)
from 586.24 ± 11.45 to 982.42 ± 6.61 μmol gallic acid equivalent (GAE)/L, and
2,2-diphenyl-1-picrylhydrazyl (DPPH) radical inhibition from 46.63 ± 1.39 to
60.87 ± 1.12%. Acid hydrolysis increased the cupric chelating activity of the
extracts while decreasing ferrous chelating activity and trans-ferulic acid
concentration significantly (p < 0.05). The acid-hydrolyzed extract at a TPC of
100 μmol GAE/L prolonged the lag phase of hexanal accumulation in the emulsion
from 0 to 8 days, while 400 μmol GAE/L TPC of unhydrolyzed extract increased
the lag phase to 12 days. The results show that acid-hydrolyzed extracts in high
concentrations may act as prooxidants
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
- …
