1-1-diphenyl-2-picrylhydrazyl and malic-acid

Chitosan - tea tree essential oil (TTEO) films were obtained as a new biodegradable material. Malic acid or lactic acid solvents were evaluated to obtain easy-removing films. The microstructure by SEM and FT-IR, the thermal properties by TGA/DSC, the mechanical properties, the water vapor permeability, the antioxidant (DPPH

Topics: Antioxidants; Benzothiazoles; Biphenyl Compounds; Chitosan; Color; Elastic Modulus; Food Packaging; Lactic Acid; Malates; Picrates; Solubility; Solvents; Sulfonic Acids; Surface Properties; Tea Tree Oil; Tensile Strength; Water

Physical characteristics, antioxidant activity and chemical constituents of 12 cultivars (Prunus avium L.) of sweet cherry (Belge, Bing, Dalbasti, Durona di Cesena, Lambert, Merton Late, Starks Gold, Summit, Sweetheart, Van, Vista, and 0-900 Ziraat) were investigated. Significant differences (P < 0.05) were observed among tested cultivars for pH, total soluble solid, hardness, color parameters, antioxidant activities and pomological measurements (P < 0.05). The color parameters were important tools for the determination of fruit maturity and anthocyanin contents. Belge cultivar showed the highest levels of total phenolic and anthocyanin, while Starks Gold contained the lowest level of anthocyanins. The darker cultivars, measured by ABTS(+•) , DPPH(•) and FRAP, exhibited higher antioxidant activities than the lighter ones. Bing (42.78 g/kg) and Sweetheart (40.53 g/kg) cultivars contained higher levels of malic acid, which was the most intense organic acid in sweet cherries. Four different sugars were observed in the samples and their concentrations ordered as glucose > fructose >> sucrose > xylose. Sugar alcohol in the cherries was represented by sorbitol (more than 90%) and its concentration varied between 13.93 and 27.12 g/kg. As a result significant differences were observed among the physical properties and chemical constituents of the cherry cultivars.

Topics: Acids; Anthocyanins; Antioxidants; Biphenyl Compounds; Carbohydrates; Color; Fruit; Humans; Malates; Phenols; Picrates; Plant Extracts; Prunus; Sorbitol; Species Specificity; Turkey

The therapeutic action of a plant depends on its chemical constituents. In this study, experiments were carried out in order to evaluate the effect of extraction conditions on the antioxidative and antimicrobial activities of Roselle (Hibiscus sabdariffa L.).. Roselle was found to be rich in malic acid, anthocyanins, ascorbic acid and minerals, especially Ca and Fe, but low in glucose. More than 18 volatile compounds were identified by gas chromatography and gas chromatography-mass spectrometry. This herb, which is rich in phenolic compounds and displays DPPH radical scavenging activity, could be a good source of natural antioxidants. The antimicrobial activity of the Roselle water and ethanol extracts was tested with Bacillus subtilis (ATCC6633), Staphylococcus aureus (ATCC6538) and Escherichia coli (ATCC 8739). The inhibition of the Roselle ethanol extract against B. subtilis and S. aureus was slightly higher than that of water extract but this difference was not significant. However, E. coli was strongly inhibited by the Roselle water extract at concentrations of 25 and 50 mg mL(-1) as determined by a paper disc method.. The obtained results indicated that antioxidant and antimicrobial activity was related to different methods of extraction and Roselle extracts could be a source of therapeutically useful products.

Topics: Anthocyanins; Anti-Bacterial Agents; Antioxidants; Ascorbic Acid; Bacillus; Bacteria; Biphenyl Compounds; Escherichia coli; Hibiscus; Malates; Minerals; Oils, Volatile; Phenols; Picrates; Plant Extracts; Staphylococcus aureus

This work relates to the development of a co-fermented product of sea buckthorn (Hippophae rhamnoides L.) with Saccharomyces cerevisiae and Issatchenkia orientalis. Besides malic acid degradation, the parameters of present production technology were also standardized with emphasis on the retainability of total phenolic content (TPC) of sea buckthorn juice. The effect of co-fermentation on physico-chemical characteristics, organic acids, flavonoids, TPC and antioxidant activities was studied. The high-performance liquid chromatography (HPLC) analysis showed 55% reduction in malic acid content after the co-fermentation of sea buckthorn juice. The TPC of sea buckthorn product was 2.18 g gallic acid equivalent (GAE)/l. The estimated scavenging effect on 2,2-diphenyl-1-picrylhydrazyl free radicals was 2.63 Trolox equivalent (TE) mmol/l. Ferric-reducing antioxidant power and 2,2'-azino-bis(3-ethylbenz-thiazoline-6-sulphonic acid) assays also showed that sea buckthorn product was on a par with commercial wines (Cabernet Shiraz and Beaujolais). We conclude that the process of co-fermentation resulted in a significant antioxidant potential of sea buckthorn product.

Topics: Antioxidants; Bacteria; Beverages; Biphenyl Compounds; Diet; Fermentation; Free Radicals; Hippophae; Humans; Malates; Phenols; Picrates; Saccharomyces cerevisiae; Wine