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Background: Biofilms and oxidative stress retard wound healing. The resistance of biofilms to antibiotics has led to a search for alternative approaches in biofilm elimination. Antioxidants work synergistically with antibacterial agents against biofilms. Hence recent research has suggested plants as candidates in the development of new alternatives in biofilm treatments and as antioxidants due to the presence of phytocompounds which are responsible for their bioactivities. Hoslundia opposita Vahl is one of the plants used by traditional healers to treat wounds and other infections, this makes it a potential candidate for drug discovery hence, in this study, we investigate the antibiofilm and antioxidant activity of methanolic extract of hoslundia opposita Vahl from Uganda. We also identify phytochemicals responsible for its bioactivity. Method: the plant was extracted by maceration using methanol, and the extract was investigated for antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) assay. The antibiofilm activity using microtiter plate assay (MTP) assay where the Minimum biofilm inhibitory concentration required to inhibit 50% or 90% of the biofilm (MBIC50 and MBIC90) and Minimum biofilm eradication concentration required to remove 50% or 90% of the biofilm (MBEC50 and MBEC90) were measured. It was further analysed for its phytochemical composition using quantitative screening, as well as Gas chromatography-mass spectrometry (GC-MS) and Liquid chromatography mass-spectrometry (LC-MS). Results: H. Opposita Vahl extract showed good antioxidant activity with of 249.6 mg/mL. It inhibited the growth of P. aeruginosa and S. aureus biofilms with MBIC50 of 28.37 mg/mL and 10 mg/mL, respectively. It showed the ability to eradicate P. aeruginosa and S. aureus biofilms with MBEC50 of 23.85 and 39.01 mg/mL respectively. Phytochemical analysis revealed the presence of alkaloids, tannins, flavonoids, and phenols. GC-MS analysis revealed 122 compounds in the extract of which, 23 have evidence of antioxidant or antibiofilm activity in literature. The most abundant compounds were; 1,4- Citric acid, Tetracontane-1,40-diol (43.43.3%, 1, Olean-12-en-28-oic acid, 3-hydroxy-, methyl ester, (3.beta) (15.36%) 9-Octadecenamide (12.50%), Squalene (11.85%) Palmitic Acid 4TMS (11.28%), and alpha Amyrin (11.27%). The LC-MS identified 115 and 57 compounds in multiple reaction mode (MRM) and scan modes respectively. Conclusion: H. opposita Vahl showed antibiofilm and antioxidant activity due to bioactive compounds identified, hence the study justifies its use for wound healing. It can be utilised in further development of new drugs as antibiofilm and antioxidants. [ABSTRACT FROM AUTHOR]

Chive (Allium schoenoprasum L.) has a strong antioxidant property as it contains abundant phenolic compounds and ascorbic acid. In the present study, we investigated the metabolism of phenolic compounds and the change in antioxidant activity in different tissue parts of post-harvest chives. The results showed that compared with the bottom white part (BW), the round green part (RG) exhibited significantly higher contents of phenolic compounds, increased enzyme activities and enhanced antioxidant activities, indicating that phenolic compounds were mainly synthesised in RG. The expression levels of genes such as phenylalanine ammonia–lyase, cinnamate 4-hydroxylase and 4-coumaroyl-CoA ligase and their corresponding enzyme activities rapidly decreased in RG, whereas they were maintained in BW, suggesting that senescence occurred more rapidly in RG than in BW. Our study provides a theoretical basis for further research into and development of different parts of Allium plants and offers a basis for consumers' nutritional considerations. [ABSTRACT FROM AUTHOR]

Introduction: Idat (Cratoxylum glaucum Korth.), belonging to the genus Cratoxylum, is known to contain xanthone, quinone, flavonoids, and other phenolic compounds. Objectives: to analyze total phenolic, flavonoid, antioxidant activity, and inhibitory xanthine oxidase activities of leaves, stem, and cortex of idat. Methods: Extraction of leaves, stem, and cortex of idat was carried out by reflux using n-hexane, ethyl acetate, and ethanol as a solvent. Antioxidant activity was tested by the DPPH method and calculated to get the antioxidant activity index (AAI). Determination of total phenolic and flavonoid levels by ultraviolet-visible spectrophotometry. Results: Spectrophotometers measured the inhibitory activity on xanthine oxidase in 96-well plates with allopurinol as standard. Total phenolic and flavonoid content from C. glaucum extracts varied from 6.62 to 48.77 g GAE/g extract and 1.54 - 25.96 g QE/100 g extract, respectively. The ethanol extracts of leaves, stem, and cortex were very strong antioxidant activity with Antioxidant Activity Index (AAI) values 3.89; 4.55; 10.50, meanwhile AAI of ascorbic acid and quercetin 9.46 and 14.81 respectively. The n-hexane of stem extract had a strong xanthine oxidase inhibitory activity with the IC50 was 36.64 µg/ml, while allopurinol was 5.02 µg/ml. Conclusions: Total phenolic content contributed to antioxidant activity. Phenolic compounds in leaves extracts led to the xanthine oxidase inhibitory and antioxidant activities. The extract of C. glaucum was active as an antioxidant and potentially an inhibitor of xanthine oxidase agents. [ABSTRACT FROM AUTHOR]

Kebar grass (Biophytum petersianum Klotzsch.) has long been known by the locals of West Papua as medicinal plant that improves fertility. The objectives of this research were to identify and determine the antioxidant activity of kebar grass crude extract through conventional method and to analyze for its antioxidant activity. Extraction method used was conventional method, performed by mixing dry kebar grass with water and boiled until the volume shrunk to 1/3 of initial volume. Analized parameters were crude extract yield, qualitative phytochemical, total phenol and antioxidant activity. Research result showed extract crude yield value of 18.32±0.01%. Qualitative phytochemical contents were dominated by flavonoid, tannin, and saponin. Total phenolic content (TPC) of crude extract was 147±1.24 mgGAE/gdw (0.688±0.01 mgGAE/gfw). Crude extract antioxidant parameter was measured as the value of inhibition, AEAC, TEAC, and IC50 where each value respectively was as followed 42.0±0.047%, 69.93±2.19 mgAE/gdw (8.30±0.26 mgAE/gfw), 65.70±1.54 mgTE/gdw (7.80±0.18 mgTE/gfw) and 0.129±0.003 mgdw (257.75±4.90 mg/L). The contribution of kebar grass TPC content to antioxidant activity is 47.38% (equal to ascorbic acid) and 44.51% (equal to trolox) which means that almost half of kebar grass crude extract's phenolic compound act as antioxidant. The results of this research can show that the kebar grass has potential as a source of multiple antioxidants, which acts as an analogue of vitamin C and vitamin E. The antioxidant activity of the kebar grass extract can be the scientific basis for the use of kebar grass as a medicinal plant for infertility problems (curative) and as a functional food ingredient for antioxidant sources that prevent a decrease in reproductive performance (preventive). [ABSTRACT FROM AUTHOR]

Objective: The medicinal plant Betula alba has been used for prevention and treatment of kidney stones. Betulin is one of the main phytochemicals of Betula alba. The aim of this study is to investigate the antioxidant and antiurolithiatic activity of betulin in vitro and in silico. For antioxidant activity, 2, 2-diphenyl-1-picrylhydrazyl (DPPH), total reducing capacity, nitric oxide (NO) radical scavenging assay, and superoxide radical scavenging assay were studied. Method: In order to study antiurolithiatic activity, three assays such as crystallization, nucleation, and aggregation of oxalate crystal in urine were performed. In silico experiments were performed by using AutoDock 4.2 tools in order to establish affinity of phytochemicals toward antioxidant enzyme and matrix metalloproteinase (MMP-2 and 9). Results: The results obtained clearly demonstrate the significant scavenging activity of betulin and cystone against DPPH, NO, and superoxide radicals in comparison to standard antioxidant L-ascorbate (L-AA). It has also been observed that betulin has the capacity to inhibit the crystallization, nucleation, and aggregation in comparison to cystone. On the other hand, betulin and L-AA showed strong affinity toward antioxidant enzymes and matrix metalloproteinase as determined by in silico experiments. Conclusions: From this, it may be concluded that the antiurolithiatic activity of betulin is, at least in part, mediated by its antioxidant property. [ABSTRACT FROM AUTHOR]

Increasing the value of the waste generated by food processing is a must from an environmental and economic point of view. This paper addresses the influence of drying temperature and ultrasound application on the drying kinetics and quality of apple peel (Royal Gala var.). Samples were dried at −10, 30, 50, and 70 °C without and with (50 W) ultrasound application. Color, antioxidant capacity, total phenolics, and ascorbic acid content were measured. Ultrasound application and drying temperature significantly shortened the drying time and affected the quality parameters. The drying carried out at 30 °C with ultrasound application was a fast process that provided samples with good color and antioxidant attributes. [ABSTRACT FROM AUTHOR]

Aims: To estimate the phytochemical and vitamins composition and the antioxidant activity of Pelargonium inquinans leaves. Background: Some plants that are used in the traditional setting for the management of different ailments have documented observations and scientific studies. However many other plants lack scientific reports to support their medicinal use. One of such plant is Pelargonium inquinans Ait that is traditionally used to treat headaches and flu by tribes in South Africa. Not much is known about its chemical composition. Methods: The phytochemical composition of acetone, aqueous and ethanol extract of leaves of Pelargonium inquinans as well as the vitamins A, C and E of its dried weight leaves and the antioxidant activities were evaluated using standard in vitro methods. The phytochemical composition and vitamins were determined spectrophotometrically, while the antioxidant activities were determined by DPPH, nitric oxide and hydrogen peroxide scavenging activity and phosphomolybdenum (total) antioxidant activity. Statistical analysis: The One-way analysis of variance (ANOVA) and the Tukey test were used to determine the differences among the means of the various samples. Results: The phytochemical composition differ significantly in the various extracts. The total phenolics were higher than other phytochemicals in all the extracts used. The hydrogen peroxide and DPPH scavenging activity were very high and dose-dependent. The aqueous extract had the highest antioxidant activity at 98.4 % of control (Hydrogen peroxide), while the ethanol extract had the lowest at 37.5% control (Nitric oxide). Conclusion: The results supports the notion that the Geraniaceae family and Pelargonium inquinans in particular is rich in polyphenolic compounds and has good antioxidant activity. [ABSTRACT FROM AUTHOR]

Highlights • Low temperature increased the total phenolics and reduced PPO enzyme activity. • Kernels treated with walnut husk extracts had the lowest total yeast and mold. • PPO enzyme activity was inhibited by Ascorbic acid. Abstract This study assessed the effects of antioxidant edible coating on the walnut green husk extract (WGHE) in combination with ascorbic acid (AsA) and the effects were studied on the postharvest quality of fresh kernels (FKs). FKs were dipped in distilled water (Control), WGHE (0.15 and 0.3 g L−1), AsA 1 % and the combination of treatments. The samples were stored for 60 days at 4 ± 1 °C with 93 % relative humidity. The results showed that low temperature increased the levels of total phenols (TP), reduced the polyphenol oxidase (PPO) enzyme activities after 15 days of storage and preserved the antioxidant activity (AC) for up to 30 days of storage. Compared with uncoated kernels, all coated samples inhibited the increase in microbial growth, peroxide index (PI) and PPO activity. The values of TP, AC, color and sensory properties were also significantly preserved as a result of coating the FKs. In summary, all edible coatings may be used to extend the shelf life of the FKs in dry environment. [ABSTRACT FROM AUTHOR]

Previous studies proved the antioxidant properties of dates. However, studies on date byproducts especially date vinegar are still lacking. Hence, it is the aim of the present study to compare the physicochemical properties, total phenolic content, and antioxidant capacity between homemade and commercial date vinegar. Physicochemical properties such as total sugar content, pH, and total titratable acidity of homemade and commercial date vinegar were studied. Both homemade and commercial date vinegar showed significant difference in physicochemical properties including pH, sugar content and total titratable acidity (p<0.05). Total phenolic content ranged from 281.17 mg GAE/L to 641.17 mg GAE/L with significant differences (p<0.05) noted between homemade and commercial date vinegar. Homemade semisoft date vinegar possessed significantly higher (p<0.05) hydrogen peroxide inhibition capacity (310.20 μg AAeq/mL) as compared to soft date vinegar (200.06 μg AAeq/mL) and commercial date vinegar (190.81 μg AAeq/mL). Pearson's correlation statistical test showed no significant correlation (p>0.05) between hydrogen peroxide scavenging activity and total phenolic content of date vinegar. Only the homemade date vinegar showed metal chelating property with values of 0.34 ± 0.10 and 2.90 ± 0.03 for semisoft and soft date cultivars respectively. Pearson's correlation statistical test showed significant correlation between metal chelating rate and total phenolic content (r=0.50; p<0.01) of the two samples. Homemade date vinegar showed generally higher antioxidant activity than commercial date vinegar and both samples were significantly different in terms of their physicochemical properties. [ABSTRACT FROM AUTHOR]

This study aimed to optimize the ultrasound extraction conditions of phenolic compounds from pomegranate (PPE) and orange peels (OPE) as agricultural wastes and use the optimized extracts to enrich a functional drink. The statistical analysis results demonstrated that the quadratic model used had high R2 (>0.89) and good predictability of experimented results. In optimizing the extraction of PPE and OPE, the effect of three factors of extraction time (X1:10–40 min), temperature (X2: 40–70 °C), and solid to a solvent ratio (X3: 1:20–1:40 g/mL) on two responses of total phenol content (TPC) and antioxidant activity were investigated. The highest TPC (2.70 and 1.86 mg GAE/g) and antioxidant activity (72.11 and 54.27%) of PPE and OPE were obtained in the X1: 40 min, X2: 70 °C, and X3: 1:40 g/mL. No significant difference was observed between the predicted and experimental values. The results of drink tests indicated that adding PPE and OPE and increasing their levels from 10% to 15% v/v in the drinks significantly enhanced the samples' bioactive compounds content and antioxidant activity (p < 0.05). The content of vitamin C (212.37 mg/100 mL) and flavonoids (83.44 mg QE/100 mL) in the drink containing 15% OPE was higher than in other samples, while the sample containing 15% PPE had the highest TPC (158.88 mg GAE/100 mL). There was a positive relationship between the level of extracts and the antioxidant activity of the drinks. During 60-days of cold storage, the content of bioactive compounds and antioxidant activity of drink samples gradually decreased (p < 0.05). [Display omitted] • Optimizing ultrasound extraction of Pomegranate (PPE) and orange peels (OPE) was done. • The functional drink was enriched by the optimized extracts of PPE and OPE. • PPE and OPE extracts were increased a functional drink's bioactive content and antioxidant activity. [ABSTRACT FROM AUTHOR]

Background: Cocoa pod is an outer part of cocoa fruits being discarded during cocoa bean processing. Authors found out that data on its usage in literature as cosmetic materials was not recorded in vast. In this study, cocoa pod extract was investigated for its potential as a cosmetic ingredient. Methods: Cocoa pod extract (CPE) composition was accomplished using UHPLC. The antioxidant capacity were measured using scavenging assay of 1,2-diphenyl-2-picrylhydrazyl (DPPH), β-carotene bleaching assay (BCB) and ferric reducing antioxidant power (FRAP). Inhibiting effect on skin degradation enzymes was carried out using elastase and collagenase assays. The skin whitening effect of CPE was determined based on mushroom tyrosinase assay and sun screening effect (UV-absorbance at 200-400 nm wavelength). Results: LC-MS/MS data showed the presence of carboxylic acid, phenolic acid, fatty acid, flavonoids (flavonol and flavones), stilbenoids and terpenoids in CPE. Results for antioxidant activity exhibited that CPE possessed good antioxidant activity, based on the mechanism of the assays compared with ascorbic acid (AA) and standardized pine bark extract (PBE); DPPH: AA > CPE > PBE; FRAP: PBE > CPE > AA; and BCB: BHT > CPE > PBE. Cocoa pod extract showed better action against elastase and collagenase enzymes in comparison with PBE and AA. Higher inhibition towards tyrosinase enzyme was exhibited by CPE than kojic acid and AA, although lower than PBE. CPE induced proliferation when tested on human fibroblast cell at low concentration. CPE also exhibited a potential as UVB sunscreen despite its low performance as a UVA sunscreen agent. Conclusions: Therefore, the CPE has high potential as a cosmetic ingredient due to its anti-wrinkle, skin whitening, and sunscreen effects. [ABSTRACT FROM AUTHOR]

The aim of this study was to examine the contribution of sugar, organic acid, neutral phenol, and anthocyanin fractions and added ascorbic acid to grape and pomegranate-nectarine juice total phenol, oxygen radical absorbance capacity ( ORAC), ferric reducing antioxidant power ( FRAP) and 2,2-diphenyl-1-picrylhydrazyl ( DPPH) values. Neutral phenol and anthocyanin fractions contributed ≥75% of the total antioxidant capacity ( TAC) for both juices. Intrinsic synergy and antagonism among the fractionated constituents occurred inconsistently in each assay. Sugars and organic acids antagonised pomegranate juice neutral phenols and anthocyanins in the DPPH assay by 50% and the grape juice ORAC value by 21%, but were synergistic to the grape juice FRAP value. The added ascorbic acid was dose-dependently synergistic with pomegranate and grape juice total phenol, DPPH and FRAP assays, but less so in the ORAC assay. Thus, the interactions between grape and pomegranate juice constituents determine TAC and total phenol values, and synergy in these assays could not be attributed solely to polyphenols. [ABSTRACT FROM AUTHOR]

The antioxidant properties of Mapo tangelo fruit and leaves extracts were investigated. The content of health-promoting components (total phenolics, flavonoids and ascorbic acid) were evaluated by spectrophotometric assays. Higher concentrations of total phenolics, flavonoids and ascorbic acid were found in peel samples extracted with boiling water, followed by leaves extracted with boiling ethanol. the radical-scavenging activity of the extracts was evaluated by different in vitro tests (total antioxidant activity, DPPH, ABTS and β-carotene bleaching tests). The trend observed for bioactive compounds was confirmed by antioxidant activity assays and good correlation values were obtained with total phenolics, flavonoids and ascorbic acid. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the effect of delactosed whey permeate (DWP) treatment on antioxidant and physicochemical properties of strawberries. Fresh strawberries treated with 3% DWP were analysed for different quality, nutritional and microbiological markers during 10 days of storage at 5 °C. The results showed that DWP treatment significantly reduced incidences of decay (70%) and numbers of total aerobic counts (∼1.4 Log10 CFU g−1) and yeast and moulds (∼1.8 Log10 CFU g−1). DWP treatment also inhibited the loss of firmness (15%) and maintained significantly ( P ≤ 0.05) higher levels of vitamin C, total phenols and antioxidant activity of strawberries. Sensory scores confirmed that the DWP-treated strawberries retained a good appearance and overall quality. The aroma and colour attributes were not reduced during storage. These results suggest that DWP treatment has potential to extend the shelf-life and maintain the quality of strawberries during storage. [ABSTRACT FROM AUTHOR]

Potential antioxidant properties of an aqueous extract of the edible red seaweed Gracilaria tenuistipitata (AEGT) against oxidative DNA damage were evaluated. The AEGT revealed several antioxidant molecules, including phenolics, flavonoids and ascorbic acid. In a cell-free assay, the extract exhibited 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity that significantly reduced H2O2-induced plasmid DNA breaks in a dose-response manner (P < 0.001). The AEGT also suppressed H2O2-induced oxidative DNA damage in H1299 cells by reducing the percentage of damaged DNA in a dose-response manner (P < 0.001) as measured by a modified alkaline comet-nuclear extract (comet-NE) assay. The MTT assay results showed that AEGT confers significant protection against H2O2-induced cytotoxicity and that AEGT itself is not cytotoxic (P < 0.001). Moreover, H2O2-induced cell cycle G2/M arrest was significantly released when cells were co-treated with different concentrations of AEGT (P < 0.001). Taken together, these findings suggest that edible red algae Gracilaria water extract can prevent H2O2-induced oxidative DNA damage and its related cellular responses. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this study was to determine the antioxidant potency and total phenolic and flavonoid contents of kiwifruit (Actinidia deliciosa) in vitro by analysing the radical scavenging activity of lyophilised water extract from kiwifruit (LEK) for 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), 1,1-diphenyl-2-picryl-hydrazyl (DPPH), N,N-dimethyl-p-phenylenediamine (DMPD), and superoxide anion radical (O 2 −) as well as the total reducing power by FRAP and CUPRAC assays and the metal chelating activities. LEK showed efficient radical scavenging activity with DPPH, ABTS, DMPD, and O 2 − radicals; ferric (Fe3+) and cupric (Cu2+) ion reducing power and metal chelating activities. Moreover, the amounts of phenolic compounds, such as caffeic acid, ferulic acid, syringic acid, ellagic acid, catechol, pyrogallol, p-hydroxy benzoic acid, vanillin, p-coumaric acid, gallic acid, quercetin, α-tocopherol and ascorbic acid, in LEK were quantified by LC-MS-MS. The results show that pyrogallol (2070.0mg/kg LEK) is the main phenolic compound responsible for the antioxidant and radical scavenging activities of LEK. Finally, total phenolic and flavonoid contents were determined as gallic acid (GAE) and quercetin equivalents (QE). The GAE and QE values in LEK were 16.67±2.83μg GAE/mg and 12.95±0.52μg QE/mg, respectively. The results suggest that consumption of kiwifruit (A. deliciosa) can be beneficial effects due to its antioxidant properties. [Copyright &y& Elsevier]

To prevent oxidative quality changes, a few selected antioxidants, ascorbic acid, or an ascorbic acid plus α-tocopherol combination were electrostatically sprayed on the surface of ground beef patties. Color, metmyoglobin, oxidation-reduction potential, lipid oxidation, and volatiles of the samples were determined during the 8 d of aerobic storage. Spraying of ascorbic acid at 500 mg/kg was the most effective in controlling discoloration of ground beef. Spraying of ascorbic acid at 500 mg/kg was also effective in reducing 2-thiobarbituric acid-reactive substances and volatile aldehydes such as hexanal and heptanal related to lipid oxidation. Spraying of phenolic antioxidants such as tocopherol, sesamol, or rosemary oleoresin showed significant (P < 0.05) antioxidant effects, but had no effects (P < 0.05) in stabilizing the color of ground beef. Sesamol at 100 mg/kg showed the most potent antioxidant activities among the antioxidants, and its antioxidant effect was as strong as that of 500 mg/kg of ascorbic acid. It was concluded that electrostatic spray of ascorbic acid on the surface of ground beef at 500 mg/kg was an efficient and economical way to prevent both lipid oxidation and color changes in ground beef. [ABSTRACT FROM AUTHOR]

Abstract: The objective of this study was to evaluate the antioxidant properties of extracts of the lucanid beetle, Serrognathus platymelus castanicolor Motschulsky, obtained at different growth stages. The antioxidant activities of six different extracts were determined using 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2''-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), and singlet oxygen (1O2). The activity level of pupal methanol extracts (PME) was higher in the DPPH and ABTS radical scavenging assays, whereas that of the water extracts was weaker in all assays. The 1O2 quenching ability of the PME was comparable to that of ascorbic acid (effective concentration of 50% 1O2 quenching: EC50 =0.184mg/ml-1 and 0.167mg/ml-1, respectively). The free radical scavenging antioxidant ability of the extracts significantly altered phenolic contents, important factors in the potency of antioxidant capacity. Our results suggest that these extracts may reduce oxidative stress in living organisms and reduce oxidative damage in insects under unfavorable conditions. [Copyright &y& Elsevier]

Abstract: Sixty-six types of vegetables commonly consumed in Singapore were analysed for their hydrophilic oxygen radical absorbance capacity (H-ORAC), total phenolic content (TPC), ascorbic acid (AA) and various lipophilic antioxidants. A single batch analysis of each vegetable showed that antioxidant composition and concentration varied widely across different vegetables. The vegetables with intense colours typically have high H-ORAC, TPC, AA, and carotenoid contents. Vegetables unique to the Asian market such as matrimony vine (Lycium chinense Miller), coriander, Chinese kale, water spinach and red chilli were consistently ranked high in H-ORAC, TPC, carotenoids and vitamin E levels. Based on consumption data, Chinese Singaporeans appear to have a higher intake of lutein, zeaxanthin, β-carotene, and tocopherols compared to the US population. Overall findings suggest that dark green leafy and brightly-coloured vegetables tend to contain high antioxidants. Our data are useful reference and substantiate many public health agencies’ recommendation to consume more vegetables, particularly the dark green leafy and brightly-coloured varieties. [Copyright &y& Elsevier]

Abstract: The effect of ultraviolet (UV-C) treatment on total phenol, flavonoid, and vitamin C content of fresh-cut honey pineapple, banana “pisang mas”, and guava was investigated. The antioxidant capacity of the fruit also was evaluated by measuring its ferric reducing/antioxidant power (FRAP) and DPPH free radical-scavenging activity. The fresh-cut fruits were exposed to UV-C for 0, 10, 20, and 30 min. Total phenol and flavonoid contents of guava and banana increased significantly with the increase in treatment time. In pineapple, the increase in total phenol content was insignificant, but the flavonoid content increased significantly after 10 min of treatment. UV-C treatment decreased the vitamin C content of all three fruits. In fresh-cut banana, longer treatment time resulted in higher FRAP and DPPH values; these values remained stable throughout the experiment for fresh-cut pineapple. For fresh-cut guava, FRAP and DPPH values were stable until 30 min, after which a significant increase in FRAP values occurred. Industrial relevance: UV irradiation processing of fresh-cut fruits leads to increase in antioxidants, polyphenols, and flavonoids. Hence, apart from the application of UV for microbial safety at industrial levels, this novel technology can also be exploited for enhancement of health promoting compounds for benefit of consumers. [Copyright &y& Elsevier]

The influence of washing treatment on the retention of key antioxidants in minimally processed iceberg lettuce was examined. Shredded iceberg lettuce was subjected to one of three washing treatments: a domestic wash (tap-rinsed), immersion in distilled water (water-dipped) or immersion in chlorinated water (chlorine-dipped). Lettuce was subsequently packed in oriented polypropylene bags and flushed with 100% nitrogen and stored at 4 °C. Vitamin C (ascorbic acid and dehydroascorbic acid), total phenols, total antioxidants, individual phenols, individual carotenoids, colour measurements and pH were quantified on production day and throughout the storage period (8 days). Different groups of antioxidants were found to differ in their response to washing treatments. No significant ( P > 0.05) effects of washing treatment were observed on total antioxidant activity, total phenolics and on the levels of individual phenolics (chicoric acid, chlorogenic acid and caffeic acid). Individual carotenoids were initially affected by washing treatment, with higher levels of lutein and beta-carotene retained with domestic washed lettuce. Ascorbic acid was the antioxidant most affected by washing treatments with domestic washing resulting in significantly ( P ≤ 0.05) higher retention of ascorbic acid throughout the storage period compared with the chlorine-dipped lettuce. [ABSTRACT FROM AUTHOR]

Abstract: The purpose of this study was to compare the antioxidant capacities of standard compounds (phenolic compounds, ascorbic acid, and glutathione) as measured by various assays. Five methods were selected so as to span a diversity of technical approaches: TEAC (radical 2,2′-azino-bis(3-ethylbenzothiazoline)-6 sulphonic acid), DPPH (radical 2,2-diphenyl-1-picryhydrazyl used to measure reducing capacity), ORAC (oxygen radical scavenging capacity), red blood cell haemolysis (protection of biological sample), and ESR (electron spin resonance for direct free radical evaluation). Most compounds showed significant differences in free radical scavenging activity according to the method used. Of the 25 tested compounds, only a few, such as myricetin and gallocatechin, gave comparable activities in the various tests. To standardise reporting on antioxidant capacity, it is proposed to use a weighted mean of the values obtained using the DPPH, ORAC, resistance to haemolysis, and ESR assays. This strategy was used to test the antioxidant capacity of several beverages. The highest antioxidant capacity was observed for red wine, followed by green tea, orange juice, grape juice, vegetable juice, and apple juice. [Copyright &y& Elsevier]

Abstract: Ether, methanolic and aqueous extracts of lyophilized rambutan (Nephelium lappaceum L.) peels and seeds were evaluated for phenolic contents, antioxidant and antibacterial activities. High amounts of phenolic compounds were found in the peel extracts and the highest content was in the methanolic fraction (542.2mg/g dry extract). Several potential antioxidant activities, including reducing power, β-carotene bleaching, linoleic peroxidation and free radical scavenging activity, were evaluated. The peel extracts exhibited higher antioxidant activity than the seed extracts in all methods determined (P <0.05). The methanolic fraction was found to be the most active antioxidant as shown by their 50% DPPH inhibition concentration, 4.94μg/mL. The results indicated this fraction exhibited greater DPPH radical scavenging activity than BHT and ascorbic acid (0.32g dry extract/g BHT or ascorbic acid). Antibacterial activity against eight bacterial strains was assessed by disc diffusion and broth macrodilution methods. All peel extracts exhibited antibacterial activity against five pathogenic bacteria. The most sensitive strain, Staphylococcus epidermidis, was inhibited by the methanolic extract (MIC 2.0mg/mL). [Copyright &y& Elsevier]

Antioxidant activity of the methanol extract of Ixora coccinea L. was determined by DPPH free radical scavenging assay, reducing power and total antioxidant capacity using phosphomolybdenum method. Preliminary phytochemical screening revealed that the extract of the flower of I. coccinea possesses flavonoids, steroids and tannin materials. The extract showed significant activities in all antioxidant assays compared to the standard antioxidant in a dose dependent manner and remarkable activities to scavenge reactive oxygen species (ROS) may be attributed to the high amount of hydrophilic phenolics. In DPPH radical scavenging assay the IC50 value of the extract was found to be 100.53 μg/mL while ascorbic acid had the IC50 value 58.92 μg/mL. Moreover, I. coccinea extract showed strong reducing power and total antioxidant capacity. [ABSTRACT FROM AUTHOR]