230 research outputs found
Vitamin Enhanced Waters and Polyphenol Rich Beverages Analyzed for Antioxidant Capacity and Antioxidants/Calorie
The purpose of this study was to analyze polyphenol rich beverages (vitamin enhanced waters (VEWs), fruit juices and berry juices) to determine free polyphenol concentrations and free polyphenols per Calorie based on a serving size. The Folin–Ciocalteu reagent was used in a colorimetric assay based on a catechin standard. Fruit and berry juices contained, on average, more than eight-times the concentration of free polyphenols when compared to VEWs. When Calories per serving were taken into consideration, fruit and berry juices contained more than twice the free polyphenols per Calorie
Growth temperature and genotype both play important roles in sorghum grain phenolic composition.
Polyphenols in sorghum grains are a source of dietary antioxidants. Polyphenols in six diverse sorghum genotypes grown under two day/night temperature regimes of optimal temperature (OT, 32/21 °C and high temperature (HT, 38/21 °C) were investigated. A total of 23 phenolic compounds were positively or tentatively identified by HPLC-DAD-ESIMS. Compared with other pigmented types, the phenolic profile of white sorghum PI563516 was simpler, since fewer polyphenols were detected. Brown sorghum IS 8525 had the highest levels of caffeic and ferulic acid, but apigenin and luteolin were not detected. Free luteolinidin and apigeninidin levels were lower under HT than OT across all genotypes (p ≤ 0.05), suggesting HT could have inhibited 3-deoxyanthocyanidins formation. These results provide new information on the effects of HT on specific polyphenols in various Australian sorghum genotypes, which might be used as a guide to grow high antioxidant sorghum grains under projected high temperature in the future
Tracking antioxidant properties and color changes in low-sugar bilberry jam as effect of processing, storage and pectin concentration
<p>Abstract</p> <p>Background</p> <p>Recently, an increased interest in the identification of valuable possibilities for preserving the antioxidant properties of products obtained by thermal processing of fruits rich in bioactive compounds can be noticed. In this regard, an extensive analysis is necessary in terms of thermal processed products behavior in relation to various factors. The purpose of the present study was to assess the effect which processing and storage at 20°C has on the antioxidant properties and color quality of low-sugar bilberry jam with different low-methoxyl pectin (LMP) concentrations.</p> <p>Results</p> <p>For all measured parameters, it should be noted that thermal processing induced significant alterations reported to the values registered for fresh fruit. Most important losses due to thermal processing were recorded for total monomeric anthocyanins (TMA) (81-84%), followed by L-ascorbic acid (L-AsAc) content (53-58%), total phenolics (TP) content (42-51%) and FRAP (ferric reducing antioxidant power) values (36-47%). Moreover, depreciation of the investigated compounds occurred during storage at 20°C. Jam storage for 7 months resulted in severe losses in TMA content in the range 58-72% from the value recorded one day after processing. This coincided with marked increases in polymeric color percent of these products after 7 months of storage. Also, bilberry jam storage for 7 months resulted in a decrease in L-AsAc content of 40-53% from the value recorded one day after processing, 41-57% in TP content and 33-46% from the value recorded one day after processing for FRAP values. By decreasing of LMP concentration in the jam recipe from 1 to 0.3% there has been an increase in losses of investigated compounds.</p> <p>Conclusion</p> <p>Overall, the results indicated that bilberry jams can also represent a good source of antioxidant compounds, although compared to the fruit, important losses seem to occur. Practical application of this work is that this kind of information will be very useful in optimizing the jam processing technology and storage conditions, in order to improve the quality of these products.</p
Regioselectivity of human UDP-glucuronosyl-transferase 1A1 in the synthesis of flavonoid glucuronides determined by metal complexation and tandem mass spectrometry
Gene-regulatory activity of alpha-tocopherol.
Vitamin E is an essential vitamin and a lipid soluble antioxidant, at least,
under in vitro conditions. The antioxidant properties of vitamin E are exerted
through its phenolic hydroxyl group, which donates hydrogen to peroxyl radicals,
resulting in the formation of stable lipid species. Beside an antioxidant role,
important cell signalling properties of vitamin E have been described. By using
gene chip technology we have identified alpha-tocopherol sensitive molecular
targets in vivo including christmas factor (involved in the blood coagulation)
and 5alpha-steroid reductase type 1 (catalyzes the conversion of testosterone to
5alpha-dihydrotestosterone) being upregulated and gamma-glutamyl-cysteinyl
synthetase (the rate limiting enzyme in GSH synthesis) being downregulated due
to alpha-tocopherol deficiency. Alpha-tocopherol regulates signal transduction
cascades not only at the mRNA but also at the miRNA level since miRNA 122a
(involved in lipid metabolism) and miRNA 125b (involved in inflammation) are
downregulated by alpha-tocopherol. Genetic polymorphisms may determine the
biological and gene-regulatory activity of alpha-tocopherol. In this context we
have recently shown that genes encoding for proteins involved in peripheral
alpha-tocopherol transport and degradation are significantly affected by the
apoE genotype
Influence of iron and ascorbate supplementation on oxidative DNA damage in healthy humans: Pro-oxidant or protective effect?
Iron supplementation and oxidative damage to DNA in healthy individuals with high plasma ascorbate
10.1006/bbrc.2001.5749Biochemical and Biophysical Research Communications2881245-251BBRC
The compositional characterisation and antioxidant activity of fresh juices from Sicilian sweet orange (Citrus sinensis L. Osbeck) varieties
- …