Analysis Of Antioxidant Potential Research Articles

Analysis of antioxidant potential and study of the features of the microstructure in certain types of spices and herbs used in the meat processing industry

Spices and herbs are widely used in the meat processing industry to improve the taste and flavor of the food products. They contain a wide range of essential oils and biologically active components possessing antioxidant potential. Surge of spices consumption leads to their adulteration; at the same time, species identification is complex and requires increased knowledge about the peculiarities of their structure. This study researched the antioxidant potential (AOP) of six spices and three fragrant herbs, defined their structure and histological parameters of their identification. To assess AOP, total antioxidant capacity (TAC) was defined using the methods of Oxygen Radical Absorbance Capacity (ORAC) and free radical DPPH, and the main classes of AO were identified with the help of qualitative reactions, microstructure was analyzed via three staining methods. Among six classes of AO the flavonoids were found in all extracts. All of four AO classes were found in basil and allspice. Allspice extract showed the highest TACDPPH (2,876.05 ± 19.83 µmol-eq.quercetin/l), the lowest value was found in parsley extract (157.97 ± 4.80 µmol-eq.quercetin/l). At the same time, the highest TACORAC was found in the extract of dill greens and basil greens — 9,789.51 ± 433.22 μmol-eq.quercetin/l and 9,692.91 ± 203.42 μmol-eq.quercetin/l, respectively, and its lowest content was found in ginger — 956.98 ± 241.79 µmol-eq. quercetin/l. The microstructural features of cells peculiar for each sample were defined: external protective tissues, seed hulls, storage tissue, secretory and formative tissues, and their ability to perceive staining with general and specific dyes. The results obtained make it possible to test the composition of dry spices and herbs, to reveal their presence in the ready-to-consume meat products and to exclude cases of their adulteration.

Phytochemical investigation and biological activities of extracts obtained from Montrichardia linifera (Arruda) Schott leaves collected in different localities from Piauí coast

Montrichardia linifera is an aquatic macrophyte widely used by the population, presenting antibacterial, antioxidant, antiplasmodic, insecticidal and antimalarial activities. This study aimed to evaluate the phytochemical composition and biological activities of extracts obtained from M. linifera leaves collected in different locations. Hexanic (HXE), hydroalcoholic (HAE) and methanolic (ME) extracts were prepared from leaves from four collection points in the state of Piauí, Brazil: Porto dos Tatus (PT), Lagoa do Bebedouro (LB), Galego (G) and Morros da Mariana (MM). Qualitative and quantitative phytochemical assays, evaluation of in vitro cytotoxicity against three tumor cell lines (HL-60, HCT-116 and B16-F10), evaluation of antibacterial activity against Escherichia coli and Staphylococcus aureus and analysis of antioxidant potential by DPPH were carried out and ABTS. The extracts showed the presence of alkaloids, organic acids, flavonoids, phenols and tannins, with their presence varying according to the place of collection. The HXE-G sample had the highest percentage of flavonoids. The ME-G and HAE-G samples had the highest levels of phenolic compounds. The HXE-G, HAE-G and ME-G extracts showed a high percentage of inhibition against the three tumor strains tested. HXE-MM had a bacteriostatic effect against both strains of bacteria tested. The samples that showed better antioxidant activity were ME-G and HAE-G. These results demonstrate that the plant has a phytochemical variability, depending on the geographic location and the type of solvent used in the extraction process. Thus, the extracts obtained from M. linifera leaves present a variety of secondary metabolites with potential biological activity.

Comparison of the antioxidant potential of some herbal teas produced from ecological and traditional crops

The growing public awareness of the dangers regarding chemicals used in traditional agriculture has led to consumers seeking valuable and contaminant-free products. Ecological agriculture has become synonymous with high health value and product safety. The aim of this study was to evaluate the antioxidant activity and the total polyphenolic content of infusions of herbal tea bags and loose teas from traditional crops, as well as infusions of loose teas from ecological crops. Raw material comprised dried flowers of Matricaria chamomilla and Tilia cordata, as well as dried leaves of Urtica dioica, Melissa officinalis and Mentha piperita. Herbal infusions were prepared using three brewing times: 5, 10 and 20 min. The analysis of antioxidant potential was performed using in vitro methods such as DPPH, ABTS and FRAP. The polyphenolic content was determined using the Folin-Ciocalteu method. The antioxidant activity of the studied tea infusion depended on the method by which the plants were cultivated and the brewing time. The ecological agriculture conditions seem not to stimulate the synthesis of antioxidants. However, the possibility to obtain other beneficial properties of the studied plants is an indication to carry out ecological cultivation.

Rapid Estimation of Tocopherol Content in Linseed and Sunflower Oils-Reactivity and Assay.

The reactivity of tocopherols with 2,2-diphenyl-1-picrylhydrazyl (DPPH) was studied in model systems in order to establish a method for quantifying vitamin E in plant oils. The method was optimized with respect to solvent composition of the assay medium, which has a large influence on the course of reaction of tocopherols with DPPH. The rate of reaction of α-tocopherol with DPPH is higher than that of γ-tocopherol in both protic and aprotic solvents. In ethyl acetate, routinely applied for the analysis of antioxidant potential (AOP) of plant oils, reactions of tocopherols with DPPH are slower and concentration of tocopherols in the assay has a large influence on their molar reactivity. In 2-propanol, however, two electrons are exchanged for both α- and γ-tocopherols, independent of their concentration. 2-propanol is not toxic and is fully compatible with polypropylene labware. The chromatographically determined content of tocopherols and their molar reactivity in the DPPH assay reveal that only tocopherols contribute to the AOP of sunflower oil, whereas the contribution of tocopherols to the AOP of linseed oil is 75%. The DPPH assay in 2-propanol can be applied for rapid and cheap estimation of vitamin E content in plant oils where tocopherols are major antioxidants.

Optimization of bioprocessing parameters using response surface methodology for bael (Aegle marmelos L.) wine with the analysis of antioxidant potential, colour and heavy metal concentration

Wine prepared from the tropical fruit bael (Aegle marmelos L.), known for its medicinal properties, is a novel beverage rich in antioxidants having enough credibility for projecting it as a medicinal wine. In the present study, bael, which is abundantly available in the region, was selected for wine production and its alcohol content was estimated using gas chromatography analysis. The conditions for the fermentation were optimised using response surface methodology. The quantitative effects of temperature, pH and duration of fermentation were investigated on fermentation of ethanol from bael using wine yeast Saccharomyces cerevisiae (NCIM 3315) as the starter culture. The optimum conditions for a 8.13% yield of ethanol were found to be temperature of 34℃, pH of 4.5 and duration of fermentation of 48 h. Biochemical analyses were conducted to study the proximate attributes of the pulp and wine with their respective changes due to fermentation. The raw bael pulp had total soluble solids 22.31°Brix, pH 5.33, total phenolics 1.94 g/100 ml and carotenoids 32.98 µg/g dw; the wine had total soluble solids 3.3°Brix, pH 4.54, total phenolics 0.96 g/100 ml and carotenoids 29.90 µg/g dw. The bael pulp and wine had 2,2-diphenyl-1- picrylhydrazyl (DPPH)-scavenging activity of 70.99% and 49.03% respectively. The Hunter colour values of the bael pulp and wine were also evaluated and the results are presented. In this study, heavy metals like Cu (0.219 mg/l), Pb (0.190 mg/l), Zn (0.002 mg/l) and Fe (3.296 mg/l) were found in the wine. The structural feasibility of bael as an effective substrate for fermentation was also confirmed by scanning electron microscopy studies.

DPPH assay of vegetable oils and model antioxidants in protic and aprotic solvents

The rate of reaction of phenolic antioxidants with DPPH depends on solvent composition. The rate constants can differ by more than two orders of magnitude for the same phenolic compound. Reactions are faster in alcohols than in ethyl acetate that is used routinely for the analysis of antioxidant potential (AOP) of nonpolar samples such as vegetable oils. Incorporation of an acid base pair into the assay solvent buffers the system against acid impurities such as free fatty acids and CO2 from the air. This is shown to increase the rate of oxidation and number of electrons of phenolic compounds exchanged with DPPH. Typically, DPPH assays are performed for predetermined time intervals at which phenolic compounds are not fully oxidized and therefore higher reaction rates result in higher values of AOP. More than twofold AOP was obtained for oleuropein, sesamol, sinapic acid, caffeic acid and protocatechuic acid in buffered alcohols than in ethyl acetate. The AOP of sesame, pumpkin seed and extra virgin olive oil is accordingly higher when determined in buffered alcohols. DPPH assays in ethyl acetate result in underestimation of AOP of unrefined vegetable oils.

Comparison of Phenolic Acids Profile and Antioxidant Potential of Six Varieties of Spelt (Triticum spelta L.)

Phenolic acids profile and antioxidant activity of six diverse varieties of spelt are reported. Antioxidant activity was assessed using eight methods based on different mechanism of action. Phenolic acids composition of spelt differed significantly between varieties and ranged from 506.6 to 1257.4 μg/g DW. Ferulic and sinapinic acids were the predominant phenolic acids found in spelt. Total ferulic acid content ranged from 144.2 to 691.5 μg/g DW. All analyzed spelt varieties possessed high antioxidant potential. In spite of the fact that bound phenolic acids possessed higher antioxidant activities, analysis of antioxidant potential and their relationship with phenolic acid content showed that free phenolics were more effective. Eight antioxidant methods were integrated to obtain a total antioxidant capacity index that may be used for comparison of total antioxidant capacity of spelt varieties. Total antioxidant potential of spelt cultivars were ordered as follows: Ceralio > Spelt INZ ≈ Ostro > Oberkulmer Rotkorn > Schwabenspelz > Schwabenkorn.

Comparison of the antioxidant potential in urine, saliva and skin.

Aim: Free radicals, oxidative stress and their possible consequences for health are becoming increasingly important in modern medicine. Reactive species influence the organism, potentially causing oxidative cell damage. They can be produced by exogenous sources, or be a product of a variety of not only physiological metabolic processes, such as immune response, but also pathological processes. The antioxidant protection system protects the organism from oxidative damage caused by reactions producing an excess of free radicals. The analysis of antioxidant potential (AOP) is therefore becoming increasingly important for the diagnosis of individual vitality.Method: The photochemoluminescence method was used to measure the AOP in urine and saliva, spectrometry was employed to measure the β-carotene content of the skin. In addition, it was investigated whether the AOPsaliva correlated with the AOPUurine (uric-acid independent AOP) as well as the β-carotene content of the skin.Results: The AOP was significantly higher in urine than in saliva, and both values were significantly positively correlated with each other. However, there was no significant correlation to the β-carotene content of the skin.Discussion: The components of the AOPUurine are accumulated over time (night), whereas AOP measurement in saliva is like a snapshot, which explains why AOPUurine was significantly higher than AOPsaliva, although the two parameters are correlated with each other. β-carotene is a fat-soluble antioxidant, whereas in our study, only water-soluble antioxidants were determined in the urine. This explains why there is no positive correlation between β-carotene of the skin and AOP.Conclusion: For the characterization of the AOP in epidemiological studies, we recommend determining the AOPUurine and parallel to this, the β-carotene content of the skin.