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Health benefits including antioxidant potential of black tea ( Camellia sinensis), lemon ( Citrus limon) and honey bees ( Apis mellifera) have been extensively reported. Nevertheless, nothing is reported about the effects of their concomitant use. Herein, those effects were evaluated in infusions of lemon-flavoured black tea with three different kinds of honey (light amber, amber and dark amber) from Lavandula stoechas, Erica sp. pl. and other indigenous floral species from north-east Portugal, a region with high amounts of this food product. Data obtained showed that the use of honey (dark amber>amber>light amber) potentiates the antioxidant activity of lemon-flavoured black tea, increasing the reducing power and lipid peroxidation inhibition properties, as also the antioxidant contents such as phenolics, flavonoids and organic acids including ascorbic acid. [ABSTRACT FROM AUTHOR]

Zizyphus (Indian ber) is an excellent source of several phenolic compounds. The effect of two cell wall degrading enzymes, namely pectinase and viscozyme, on the nutraceutical composition of Zizyphus juice was investigated in the present study. Enzyme assisted processing significantly ( P  <  0.05) improved the juice yield, total soluble solids, total phenolics and total antioxidant activity (AOX). There was significant increase in recovery of antioxidants, to the tune of 70.51%, 66%, and 45% respectively in ascorbic acid, total phenolics and total flavonoids through viscozyme. The in-vitro total AOX of juice extracted via enzyme-assisted processing was 20.9 and 15.59  μμmol Trolox/ml in ferric-reducing antioxidant power and cupric-reducing antioxidant capacity assays, respectively. There was 41% increase in AOX of juice extracted with enzyme over straight pressed juice. Results indicate that enzyme-assisted processing can significantly improve the functional properties of the Zizyphus juice. [ABSTRACT FROM AUTHOR]

The present research aimed at evaluating the vitamin C, total phenolic content (TPC), phenolic compounds, carotenoids, and chlorophyll contents, as well as antioxidant activity (AAC) of six Actinidia species fruit. Vitamin C, phenolic compounds, carotenoids and chlorophylls were measured using high-performance liquid chromatography. TPC was determined using the Folin–Ciocalteau reagent, and AAC using 2,2-diphenyl-1-picryl hydrazyl (DPPH) assay. The highest concentrations of vitamin C and TPC were found for Actinidia kolomikta fruit (1008.3 and 634.1 mg/100 g fresh weight [FW], respectively). Among phenolic compounds, seven phenolic acids and three flavonoids were identified. The 2,5-dihydroxybenzoic acid prevailed in A. kolomikta (425.54 mg/100 g FW), while tannic acid dominated in other species (4.63–100.43 mg/100 g FW). The largest amounts of chlorophylls and carotenoids were identified as Actinidia macrosperma (4.02 and 2.09 mg/100 g FW, respectively). The AAC of fruit extracts decreased in the order of A. kolomikta > Actinidia purpurea > Actinidia melanandra > A. macrosperma > Actinidia arguta > Actinidia deliciosa according to the DPPH assay. [ABSTRACT FROM AUTHOR]

Adenophora triphylla is commonly used in food materials and oriental medicine as an analgesic, anti-inflammatory, and antitussive. In the present study, the leaves and roots of A. triphylla were extracted with water and ethanol, respectively, to examine the extracts' in vitro antioxidant activities and total phenolic contents, as well as A. triphylla's potential as a new functional food source and safe and inexpensive supply of antioxidants. Different antioxidant tests were employed and the results were compared with ascorbic acid as a standard antioxidant. The total extractable contents of phenolic compounds and flavonoids, which relate to antioxidant activity in medicinal plants, were also measured. The leaf extracts had notable levels of total phenolics and flavonoids and showed high radical and nitrite scavenging activities as well as inhibition activity against enzymes that induce oxidation. These results suggest that A. triphylla leaves are a potential ingredient for food supplements and a natural source of antioxidants. [ABSTRACT FROM AUTHOR]

The objective of this study was to compare the antioxidant activities, total phenolics, lycopene and ascorbic acid content of four commercial tomato cultivars (Excell, Tradiro, Flavourine and Campari) of New Zealand, grown under similar hydroponic conditions. The mean antioxidant activity of the four cultivars, as measured with the ABTS radical decolourization assay, ranged from 2329 to 3268 µmole TEAC/100 g dry matter (DM) in the hydrophilic extracts and from 178 to 303 µmole TEAC/100 g DM in the lipophilic extracts. The major antioxidant components per 100 g DM were phenolics (343–451 mg gallic acid equivalents in hydrophilic extract and 53–74 mg gallic acid equivalents in lipophilic extract), flavonoids (175–204 mg rutin equivalents), ascorbic acid (153–195 mg) and lycopene (33–54 mg). Ascorbic acid and flavonoids were found to contribute 28–38% and 29–34%, respectively, to the antioxidant activity of the hydrophilic extract of tomatoes. The results showed that the smallest cultivar (Campari) had significantly ( P 0.05) higher antioxidant activities, total phenolics and flavonoids than the larger sized cultivars (Excell, Tradiro and Flavourine). This could be attributed to the significantly ( P 0.05) higher surface area/volume ratio of the small cultivar (0.15) when compared with the large-sized cultivars (0.10–0.12). The tomato cultivar (Flavourine) with a brighter red colour (higher a */ b * value), had a higher lycopene content as well, which suggests that the a */ b * value of tomatoes can be used as an indicator of their lycopene content. The phenolics ( r =0.84**) and flavonoids ( r =0.88**) were significantly related to the antioxidant activity of the hydrophilic extract, which suggests that measurement of total phenolics or flavonoids can be used as indicators of the antioxidant activity of tomatoes. [ABSTRACT FROM AUTHOR]