The chemical diversity of natural antioxidants (AOXs) makes it difficult to separate, detect, and quantify individual from a complex food/biological matrix. Moreover, the total antioxidant power is often more meaningful evaluate health beneficial effects because cooperative action species. Currently, there no single assay for food labeling lack standard quantification methods. Antioxidant assays may be broadly classified as electron transfer (ET)- hydrogen atom (HAT)-based assays. results...

Kinetics and stoichiometry of reactions between the 2,2-diphenyl-1-picrylhydrazyl (DPPH) stable radical 25 antioxidant compounds with different structure, molecular weight, number -OH groups, redox potential were investigated by recording loss DPPH(•) absorbance at 515 nm continuously for 10 min. A series concentrations was tested to determine linear response ranges reaction saturation points. The primary feature distinguishing activity--rate initial (<30 s)--was controlled whether dominant...

Cranberry fruit is a rich source of polyphenols, and has shown biological activities against Streptococcus mutans. In the present study, we examined influence extracts flavonols (FLAV), anthocyanins (A) proanthocyanidins (PAC) from cranberry on virulence factors involved in mutans biofilm development acidogenicity. PAC FLAV, alone or combination, inhibited surface-adsorbed glucosyltransferases F-ATPases activities, acid production by S. cells. Furthermore, acidogenicity were significantly...

Abstract Researchers from Rutgers University and Clemson have collaborated to develop a concept of using smart blending generate functional packaging films for the controlled release active compounds such as antimicrobials, antioxidants flavour extend shelf‐life food. In this paper, literature results are reviewed justify significance (CRP) research gaps further development identified. A major gap is lack materials that can provide at rates suitable wide range food applications. Smart...

Abstract A comprehensive reaction schema for oxidative cytotoxicity is presented, integrating known chemical mechanisms of oxygen radical reactions and observed pathophysiology. The key features the are coupling (1) redox cycling autoxidizable substrates to form equilibrium pair superoxide anion (O − 2 )/and its conjugate acid, perhydroxyl (HO ); (2) hydrogen peroxide (H O ) generation via dismutation; (3) catalytic metals reducing H reactive hydroxyl radicals (OH); (4) direct OH with target...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTInteraction of peroxidizing methyl linoleate with some proteins and amino acidsMarcus. Karel, Karen. Schaich, Ram B. RoyCite this: J. Agric. Food Chem. 1975, 23, 2, 159–163Publication Date (Print):March 1, 1975Publication History Published online1 May 2002Published inissue 1 March 1975https://pubs.acs.org/doi/10.1021/jf60198a046https://doi.org/10.1021/jf60198a046research-articleACS PublicationsRequest reuse permissionsArticle...

Assays developed to measure radical scavenging ability of natural compounds have been used as a basis for ranking and recommending best foods consumption. However, assays often were adapted screening with inadequate consideration reaction chemistry, particularly kinetics. Recent research results raise serious questions about the execution, application these assays. This paper critically evaluates conceptual technical issues that limit use compromise validity three commonly-used –...

Reaction kinetics in the Trolox equivalent antioxidant capacity (TEAC) assay between ABTS(+•) [2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) cation radical] and compounds with different structure, molecular weight, number of OH groups, redox potential were investigated by recording loss absorbance (734 nm) continuously over time. Curves showed six distinguishable kinetic patterns, including both immediate extended reaction components. Radical quenching rates component most relevant...

Abstract— We report on autooxidation reactions related to selective cell killing in vivo and present oxygen uptake EPR data the molecular nature of these changes, with a note reaction used test for singlet oxygen. Selective obliteration by 6‐hydroxydopamine, 6‐aminodopamine their congeners beta‐adrenergic receptors adrenergic dopaminergic neurons vitro have been reported recently. These effects devolve from autoxidation compounds situ after appropriate biological concentration, but it is...

Abstract Free radical transfer from oxidizing methyl linoleate to amino acids and proteins was studied in dry model systems incubated for periods up 20 days. Electron spin resonance used study free production. radicals were detectable the lysine, arginine, histidine, tryptophan, cysteine. Reduced glutathione and, a limited extent, cystine also gave signals. produced primarily showed central singlet lines, attributable carbon‐centered radicals, with g=2.004±0.001. Sulfhydryl exhibited...

Abstract For the past few decades, research on lipid oxidation mechanisms has been rather stagnant due to a pervasive attitude that reactions of were well understood, so only tailoring applications basic knowledge stabilize individual systems was needed. This simplistic approach worked during low fat/no fat era because there little substrate oxidize. However, with current reformulation foods polyunsaturated fatty acids for health, preventing these essential presents major challenges cannot...

Abstract Metal catalysis of membrane lipid oxidation has been thought to occur only at cell surfaces. However, conflicting observations the pro‐oxidant activity ferric (Fe 3+ ) vs ferrous 2+ forms various chelates have raised questions regarding this dogma. This paper suggests that solubilities iron complexes in phases and corresponding abilities initiate there, either directly or via Fenton‐like production reactive hydroxyl radicals, are critical determinants initial catalytic...