Terms Of Total Antioxidant Capacity Research Articles

In vitro bioactivity and phytochemical screening of selected spices used in Mauritian foods

ObjectiveTo investigate the in vitro antioxidant and antimicrobial activities along with phytochemical screening of organic and aqueous extracts of spices used in Mauritian foods. MethodsAntioxidant activity of the crude extracts was evaluated in terms of total antioxidant capacity, total phenol content and total flavonoid content. The antimicrobial activity of the spices was determined by the agar well diffusion method against a gram positive and a gram negative bacteria. The qualitative and quantitative phytochemical screening were carried out by standard biochemical assays. ResultsAll six spices were found to possess alkaloids, coumarins, flavonoids, saponins, steroids, tannins and phenols. Total phenolic content of the extracts varied between 177 and 1 890 mg GAE/g DW while the total flavonoid content varied between 2.8 and 37.6 mg QE/g DW. All six spices were found to possess strong antioxidant properties as well. Highest value was obtained for cinnamon [(24.930±0.198) μmol Fe2+/g DW] whilst turmeric showed the lowest antioxidant activity [(5.980±0.313) μmol Fe2+/g DW] (P<0.05). All extracts showed promising activity against Staphylococcus aureus and Escherichia coli. The size of the inhibition zones ranged between (11.20±0.23) mm to (26.10±2.09) mm (P<0.05) with turmeric and cinnamon being the most effective against Staphylococcus aureus while garlic was least effective against both E. coli and S. aureus. ConclusionsThe present study reveals the presence of potential antioxidant and antimicrobial properties in the extracts of the spices which could be further exploited.

Antioxidant potential of Agrobacterium-transformed and non-transformed Physalis ixocarpa plants grown in vitro and ex vitro

Oxidative stress is involved in pathogenesis of a number of chronic diseases hence is an increasing interest in plant-derived natural antioxidants with respect to their potential health benefits. Plants from the genus Physalis are particularly rich in secondary metabolites and show significant antioxidant potential. Recent development in transgenic research has opened new possibilities for enhanced production of secondary metabolites with plant cell and organ cultures. The hairy root-regenerated Physalis ixocarpa plants grown in vitro and ex vitro were compared to the non-transformed plants with respect to their antioxidant potential. The total antioxidant capacity (TAC), the contents of total phenols and ascorbate were evaluated in fruits, flowers, leaves and roots of P. ixocarpa using the ferric reducing antioxidant power assay (FRAP), the Folin-Ciocalteu method and the 2,2'-dipyridyl method, respectively. The antioxidant profiles, in terms of TAC, ascorbate and phenols were organ-specific and depended on the culture conditions. Neither the total phenol content nor the ascorbate level appeared to determine the TAC of the studied plant extracts. The aqueous extracts exhibited lower antioxidant activities than the acetone ones indicating that lipophilic antioxidants made a major contribution to TAC of the plant tissues. Agrobacterium rhizogenes-mediated transformation changed the antioxidant status with respect to TAC, phenols and ascorbate and this effect was observed in the plants grown in vitro and ex vitro.

Phenolic compounds and antioxidant activities of chestnut (Castanea sativaMill.) fruits

Introduction Anatolia is one of the original centers of European chestnut production. Therefore, chestnut fruits were procured from four regions, 16 provinces in which chestnuts are grown in Turkey and examined in terms of phenolic content, antioxidant activity and some phenolic compounds. Objectives Chestnut has become increasingly important because of positive health effects. We aimed to determine whether chestnut is a natural antioxidant source and to learn the phenolic profiles of chestnuts of some provinces of Turkey. Methods Total phenolic contents,total antioxidant capacities and specific phenolic compounds of chestnuts were determined. Fifteen antioxidant standards were used in high-performance liquid chromatography with diode-array etection for phenolic compounds’ analyses. Results The results show that the total phenolic contents varied between 5 mg GAE g -1 DM and 32.82 mg GAE g -1 DM.All chestnut samples had no significant differences statistically in terms of total antioxidant capacity. Among the specific phenolic analytes, myricetin, kaempferol, fumaric acid and quercetin were not found in any chestnut. In all chestnut samples, vanillic acid was determined in relatively high amounts. Conclusion It could be concluded that total phenolic contents and specific phenolic compounds varied between the provinces; the total antioxidant capacities were nearly the same statistically in Turkey.

In vitro bioactivity and phytochemical screening of Suaeda maritima (Dumort): A mangrove associate from Bhitarkanika, India

Objective To investigate the in vitro antioxidant and antimicrobial activities along with phytochemical screening of organic and aqueous extracts of leaf and stem of Suaeda maritima (Dumort), a mangrove associate from Bhitarkanika of Odisha, India. Methods Antioxidant activity of the crude extracts was evaluated in terms of total antioxidant capacity, total phenol content, ascorbic acid content, DPPH radical scavenging, metal chelating, nitric oxide scavenging, and reducing power etc. The antimicrobial activity of the plant was determined by agar well diffusion method along with MIC and MBC carried out by microdilution techniques against 10 gram positive and gram negative human pathogenic bacteria. The qualitative and quantative phytochemical screening were carried out by standard biochemical assays. Results Out of the seven antioxidant bioassays, both the leaf and stem extracts were found to posses strong antioxidant properties of 70 % to 92 % for phenol, total antioxidant capacity, DPPH free radical scavenging activity and fairly good ascorbic acid content, metal chelating (1.33 %-22.55 %), reducing power (0.01-0.12) and nitric oxide scavenging (0.84 %-66.99 %) activities. Out of the four extracts evaluated for antimicrobial activity, two leaf extracts such as acetone and ethanol showed promising activity against four pathogenic bacteria and one stem methanol extracts against one pathogenic bacteria when compared with amoxcycillin as standard. The MIC and MBC values of the antimicrobial extracts ranged between 2.5 to 5.0 mg/mL. Screening of phytochemicals showed presence of carbohydrates, protein, tannins, alkaloids and flavonoids in comparatively higher amount than other phytochemicals tested. Conclusions The present study reveals the presence of potential antioxidants and antimicrobial properties in the plant extract which could be exploited for pharmaceutical application.

The effect of solvent extraction on antioxidant properties of apricot fruit

Abstract Two solvent extraction procedures were used to investigate the extraction efficiency in terms of total antioxidant capacity and total phenols in apricot fruit. Samples were either sequentially extracted with aqueous ethanol (ethanol/water 80% v/v) and tetrahydrofuran or directly extracted with tetrahydrofuran. Each extract was analyzed for total antioxidant capacity by the Trolox Equivalent Antioxidant Capacity (TEAC) assay and total phenols by the Folin-Ciocalteu assay. The results showed that using sequential solvent extraction, the majority (85%) of the total antioxidant capacity and total phenols was due to hydrophilic compounds. In tetrahydrofuran direct extractions, the total antioxidant capacity and total phenols were higher than values obtained with aqueous ethanol and the sum of results obtained from sequential extracts for either total antioxidant capacity or total phenols was similar to the tetrahydrofuran-extract antioxidant values. A linear correlation between total antioxidant capacity and total phenols was found and was independent of the solvent extraction method. In conclusion, the choice of solvent is related to the antioxidant potential of fruit and depends on the food hydrophilic/lipophilic composition.

Stability of the total antioxidant capacity and total polyphenol content of 23 commercially available vegetable juices before and after in vitro digestion measured by FRAP, DPPH, ABTS and Folin–Ciocalteu methods

Vegetables are known to contain a wide variety of antioxidants which may provide protection against the development of a number of disease states. Recently there has been a large increase in the number of vegetable juices which have become commercially available. The objective of the present study was to analyse the total antioxidant capacity of 23 commercially available vegetable juices [via Ferric Reducing Antioxidant Power (FRAP), 2, 2-diphenyl-1-picrylhydrazyl (DPPH), 2, 2-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS+) and Folin–Ciocalteu Reagent (FCR) for total polyphenols] and to determine the stability of the antioxidant capacity following an in vitro digestion procedure using the same methods. All 23 juices were significant sources of antioxidants both in terms of total antioxidant capacity and total polyphenols, although results varied considerably between the juices [1369–9500μmol/L (FRAP), 57.8–100% inhibition of DPPH, 10.9–90.7% inhibition of ABTS+ and 449–3025μg ferulic acid equivalents/mL for FCR]. Beetroot juice displayed the highest level of total antioxidants and total polyphenols compared to the other juices which were analysed (tomato, carrot, mixed vegetable, mixed fruit and vegetable). The antioxidant capacity of the juices remained high throughout the in vitro digestion.

The Effects of Municipal Solid Waste Compost And Compost Tea on Mineral Element Uptake And Fruit Quality of Strawberries

Three levels of municipal solid waste compost (MSWC) and two application rates of compost tea made with MSWC were applied to strawberries for two years. The highest level of application of MSWC significantly increased the concentrations of most extractable soil mineral elements except for Ni which was increased in the highest compost tea application rate. Despite large differences in soil mineral element concentrations among treatments, plant and fruit uptake were generally unaffected by treatments. Notably however, compost tea applications increased fruit Na levels perhaps due to increased uptake of Na by leaves compared to roots. Generally, the composts and compost teas produced fruit of equal quality in terms of total antioxidant capacity and vitamin C but all treatments failed to provide sufficient N to strawberry plants and all fruit appeared to have leather rot; consequently, yield was decreased.