Oxygen Radical Absorbance Capacity Method Research Articles

Behavior of bioactive compounds and antioxidant activity of mango (Azucar cultivar) juice during storage at 4 ºC

Mango (Mangifera indica L.) is one the fruits that have shown antioxidant activity and high nutritional value. It was evaluated the effect of storage time and temperature on polyphenol content, ascorbic acid and antioxidant activity of mango (cv. Azucar) juice stored up to 64 days at 4 °C. Total polyphenol content was measured by Folin-Ciocalteu method, mangiferin and ascorbic acid were measured by HPLC (High-Performance Liquid Chromatography) and antioxidant activity was measured by ORAC (Oxygen Radical Absorbance Capacity), and ABTS•+ (2,2’-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) method. Total phenolic content decreased after 16 days of juice storage. Ascorbic acid values did not show significant differences until 48 days of storage, and mangiferin content was very similar throughout storage time. The antioxidant activity measured by ORAC method was similar until the end of the storage; however, ABTS value decreased after 32 days of juice storage. In conclusion, storage up to 32 days of mango juice at 4 °C did not alter its antioxidant activity and ascorbic acid content.

Human urine metabolomic signature after ingestion of polyphenol-rich juice of purple grumixama (Eugenia brasiliensis Lam.)

Polyphenol intake has been associated with health promotion because of its interaction with several metabolic pathways. This study investigates changes in the urine metabolome following acute intake of polyphenol-rich juice, purple grumixama juice. Grumixama (Eugenia brasiliensis Lam.) is a cherry native to Brazil that is known to be a rich source of anthocyanins and ellagitannins. In this research 15 healthy subjects consumed a single dose of grumixama juice. Urine samples were collected before grumixama juice intake, 0–1, 1–2, 2–4 h, with fasting at 24 h after intake. Plasma samples were also collected before intake, 30′ and at 1 h, 2 h and 4 h, with fasting at 24 h after juice intake. The urine primary metabolites were analysed by a metabolomic approach using gas chromatography mass spectrometry with methyl chloroformate derivatisation for amino acids and organic acids. Also, an oxygen radical absorbance capacity method was carried out to evaluate the plasma samples antioxidant capacity changes. Subjects showed increase in plasma antioxidant capacity after juice intake (p-values < .05). A total of 114 metabolites were assessed in urine (1–2 h and 2–4 h), including 17 amino acids, 47 organic acids and several other metabolites. Among the 114 metabolites, 25 were significantly changed during the first 4 h following juice intake, as shown by the Orthogonal Partial Least Squares Discriminant Analysis (0.5 > p(corr) > 0.3) and univariate analysis (p-values < .05). Some metabolites were related to mitochondrial metabolism, such as glyoxylic acid and oxalic acid. Metabolites related to amino acid metabolism were also changed, such as beta-alanine, l-phenylalanine and l-tyrosine. In conclusion, results suggest that acute intake of grumixama juice could affect amino acid metabolism and mitochondrial metabolism, but the related health implications should be explored in further studies using additional approaches.

Comparison of Germination-Parboiling, Freeze-Thaw Cycle and High Pressure Processing on Phytochemical Content and Antioxidant Activity in Brown Rice Evaluated after Cooking and In-Vitro Digestion

Abstract Three treatments, namely germination-parboiling (PG), freeze-thaw cycle (FTC) and high pressure processing (HPP) were compared for phytochemical content and antioxidant activity of brown rice (BR). These were determined in raw (uncooked), cooked, and in-vitro digested BR and compared with those from untreated BR and white rice (WR). PG showed the highest retention of phytochemicals after cooking (87–100%) while it dropped to 59–72% with FTC and 64–76% with HPP. After in-vitro digestion, the highest amount of phenolics was found in PG-24 h and flavonoids in FTC for two cycles. The antioxidant activity, as determined by oxygen radical absorbance capacity and ABTS methods, showed the highest value to be associated with in-vitro digested sample of PG-24 h, and lowest in WR. The results of this study show that these three treatments could improve or retain the phenolic content and antioxidant activity in cooked BR after in-vitro digestion.

Improvement of oxidation stability of biodiesel by an antioxidant component contained in spent coffee grounds

ABSTRACTIn this work, biodiesel was produced from spent coffee grounds (SCG) oil extracted using n-hexane as a non-polar solvent, and acetone and 1-butanol as polar solvents, in order to simultaneously obtain SCG oil and antioxidant component. Moreover, oxidation stability and antioxidant capacity of SCG oil and their biodiesel production process were evaluated using the Rancimat method and oxygen radical absorbance capacity (ORAC) method, respectively. ORAC values of SCG oil from polar solvents and a non-polar solvent were 97–98 and 93–386 μmol-TE/g, respectively. Antioxidant activities of SCG oils from polar solvents were higher than those of SCG oil from non-polar solvent. However, these ORAC values were decreased by one third on raw oils during biodiesel production model experimental. These characteristics were utilized to develop an improved method of producing waste rapeseed biodiesel: (1) blending the SCG oil with rapeseed oil; (2) soaking powdered SCG in the reaction mixture during biodiesel production; and (3) adding active components extracted using methanol. In method (1), oxidation stability was improved such that 10 wt% of polar solvent extracted SCG oils increased the stability from 1 to 3 h. Also, oxidation stabilities in methods (2) and (3) were improved by soaking 40 wt% SCG and adding 1 wt% SCG extract, respectively.

Antimicrobial, cytotoxic and antioxidative evaluation of natural deep eutectic solvents.

Natural deep eutectic solvents (NADES) are a new generation of green solvents. They are mixtures of two or three compounds such as choline chloride as a cationic salt and alcohols, acids, amides, amines or sugars as hydrogen-bond donors. Although the majority of NADES' components are of natural origin and therefore NADES are often presumed to be non-toxic, the evaluation of their toxicity and biodegradability must accompany the research on their synthesis and application. Therefore, the aim of this work was to investigate the effect of ten synthesised NADES towards bacteria (i.e., Escherichia coli, Proteus mirabilis, Salmonella typhimurium, Pseudomonas aeruginosa, Staphylococcus aureus), yeast (i.e., Candida albicans) and human cell lines (i.e., HeLa, MCF-7 and HEK293T). In addition, oxygen radical absorbance capacity (ORAC) method was used to determine the antioxidative activity of the tested NADES. Differences in toxicity response between microorganisms and cell lines were observed, and only NADES that contained organic acid showed toxicity towards the test systems. Furthermore, the NADES containing compounds that possess antioxidative activity also showed antioxidative activity. However, research whose primary purpose is the synthesis and application of NADES must be followed by an evaluation of their biological properties (e.g., antimicrobial activity, toxicity towards animal cells and antioxidative or other biological activity) to find the solvent with the best profile for wider industrial applications.

Polyphenolic Characterization and Antioxidant Activity of Malus domestica and Prunus domestica Cultivars from Costa Rica.

The phenolic composition of skin and flesh from Malus domestica apples (Anna cultivar) and Prunus domestica plums (satsuma cultivar) commercial cultivars in Costa Rica, was studied using Ultra Performance Liquid Chromatography coupled with High Resolution Mass Spectrometry (UPLC-DAD-ESI-MS) on enriched-phenolic extracts, with particular emphasis in proanthocyanidin and flavonoids characterization. A total of 52 compounds were identified, including 21 proanthocyanidins ([(+)-catechin and (−)-epicatechin]) flavan-3-ols monomers, five procyanidin B-type dimers and two procyanidin A-type dimers, five procyanidin B-type trimers and two procyanidin A-type trimers, as well as one procyanidin B-type tetramer, two procyanidin B-type pentamers, and two flavan-3-ol gallates); 15 flavonoids (kaempferol, quercetin and naringenin derivatives); nine phenolic acids (protochatechuic, caffeoylquinic, and hydroxycinnamic acid derivatives); five hydroxychalcones (phloretin and 3-hydroxyphloretin derivatives); and two isoprenoid glycosides (vomifoliol derivatives). These findings constitute the first report of such a high number and diversity of compounds in skins of one single plum cultivar and of the presence of proanthocyanidin pentamers in apple skins. Also, it is the first time that such a large number of glycosylated flavonoids and proanthocyanidins are reported in skins and flesh of a single plum cultivar. In addition, total phenolic content (TPC) was measured with high values observed for all samples, especially for fruits skins with a TPC of 619.6 and 640.3 mg gallic acid equivalents/g extract respectively for apple and plum. Antioxidant potential using 2,2-diphenyl-1-picrylhidrazyl (DPPH) and oxygen radical absorbance capacity (ORAC) methods were evaluated, with results showing also high values for all samples, especially again for fruit skins with IC50 of 4.54 and 5.19 µg/mL (DPPH) and 16.8 and 14.6 mmol TE/g (ORAC) respectively for apple and plum, indicating the potential value of these extracts. Significant negative correlation was found for both apple and plum samples between TPC and DPPH antioxidant values, especially for plum fruits (R = −0.981, p < 0.05) as well as significant positive correlation between TPC and ORAC, also especially for plum fruits (R = 0.993, p < 0.05) and between both, DPPH and ORAC antioxidant methods (R = 0.994, p < 0.05).

Investigation of Distribution of Antioxidant Compounds from Natural Sources and Study of Lipid Protection in Oil-in-Water Emulsions

The investigation of the distribution of antioxidant compounds between emulsions phases, employing natural sources of these compounds directly in the emulsions, is rarely addressed. The use of ultra performance liquid chromatography coupled to a mass spectrometer (UPLC-MS), combined with accelerated oxidation tests and oxygen radical absorbance capacity method (ORAC), using the fluorescein (FL) decay curve (ORACFL) assay, enable an improved evaluation of the distribution of the antioxidant compounds and their lipid protection abilities. The lipid protection tendency observed was in agreement with the polar paradox theory. The ORACFL results reported here are higher than other reported in the literature, even when performing a sample extraction directly into one of the emulsion phases, thus demonstrating the effectiveness of this direct addition regarding the antioxidant activity. The analysis of the mass spectra of the emulsions enabled to verify the existence and distribution of some phenolic compounds in both phases. The direct extraction in the aqueous and oil phases of the emulsion increased, in a general way, the amount of identified compounds in each phase.

Antioxidant, anti-inflammatory, and antiproliferative activity of extracts obtained from Tabebuia Rosea (Bertol.) DC

Background: Tabebuia rosea (Bertol.) DC. is a neotropical tree used in traditional medicine in the Northern coast of Colombia as well as Latin America for infectious diseases treatment. Few studies have evaluated the biological activity of this species. Objective: The objective of this study is to determine the antioxidant, anti-inflammatory, and antiproliferative potential of leaf and inner bark extracts from T. rosea. Materials and Methods: The antioxidant activity was determined using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and oxygen radical absorbance capacity (ORAC) methods. The anti-inflammatory activity was evaluated in lipopolysaccharide-stimulated murine macrophages. In vitro antiproliferative effect was determined in HepG2, HeLa, MCF-7, and B16F10 cell lines. Results: The highest DPPH radical scavenging activity was observed for T. rosea ethyl acetate leaf extract (IC50of 157.5 ± 2.4 μg/mL). This extract also induced the best antioxidant activity as determined by ORAC (11,112.2 ± 1,255.3 μmol TE/g of extract). Moreover, T. rosea leaf n-hexane, chloroform, and aqueous extracts, in addition to inner bark aqueous extract did inhibit nitric oxide production by over 90%. In addition, inner bark extracts markedly inhibited prostaglandins E2 and tumor necrosis factor alpha (>90%). The best antiproliferative activity was displayed by the inner bark chloroform extract against HepG2 (selectivity index [SI] = 5.50) and B16F10 (SI = 3.18) cell lines. Conclusion: These results demonstrate the potential biological activity of T. rosea extracts. Abbreviations used: DPPH: 2,2-diphenyl-1-picrylhydrazyl; ORAC: Oxygen radical absorbance capacity; LPS: Lipopolysaccharide; NO: Nitric oxide; TNF-a: Tumor Necrosis Factor Alpha; PGE2: Prostaglandin E2; TAC: Total antioxidant content; MTT: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide.

High fat diet and high polyphenols beverages effects in enzymatic and non-enzymatic antioxidant activity.

High fat diets have been implicated in the generation of reactive oxygen species (ROS). Polyphenols from grapes may reduce ROS and restore oxidative balance. The aim of this study is to investigate the antioxidant properties of high polyphenols beverages associated with a high fat diet in enzymatic and non-enzymatic antioxidant activity. Fifty female rats were divided into five groups: a) control group (CG) - control diet (4% fat); b) high fat diet group (HFD) - high fat diet (20% fat); c) grape juice group (GJ) - grape juice (15 ml/day) + high fat diet; d) red wine group (RW) - red wine (10 ml/day) + high fat diet; and e) resveratrol solution group (RS) - resveratrol solution (15 ml/day) + high fat diet. Eight weeks later, the superoxide dismutase, catalase and glutathione peroxidase activities were measured. Superoxide dismutase activity was assayed by measuring the inhibition of adrenaline auto-oxidation, catalase by the decrease rate in hydrogen peroxide and glutathione peroxidase by monitoring the oxidation of nicotinamide adenine dinucleotide phosphate. Non-enzymatic antioxidant activity was assessed by oxygen radical absorbance capacity and DDPH (free radical sequestration 2,2-diphenyl-1-picryhydracil) method in the animal's plasma. GC and GJ presented the lowest glutathione peroxidase activity, pointing to a possible protective effect of grape juice against high levels of ROS (p < 0.05). RW increased catalase activity when compared to the RS (p <0 .05). Superoxide dismutase activity and non-enzymatic antioxidant plasma activity were similar in all groups. Grape juice showed to be the most effective in minimizing the deleterious effects of a high fat diet. Resveratrol did not present any benefit and red wine possibly shows a harmful effect due to ethanol content.

Dual Biological Functions of a Cytoprotective Effect and Apoptosis Induction by Bioavailable Marine Carotenoid Fucoxanthinol through Modulation of the Nrf2 Activation in RAW264.7 Macrophage Cells.

In this study, the function of fucoxanthinol (FxOH) as a bioavailable marine carotenoid together with the pre-metabolite, fucoxanthin (Fx), was examined through the Nrf2-ARE pathway. The antioxidant activity in the low concentration range of the compounds (1–4 μM) with a peroxyl radical scavenging capacity was proved by the ORAC (Oxygen Radical Absorbance Capacity) method and an ESR study. Similar concentrations of the compound also activated the Nrf2-ARE signaling with the Nrf2 translocation into the nuclear, then the expression of the antioxidant protein HO-1 increased. On the other hand, the high concentrations of both compounds (>10 μM) induced apoptosis with caspase 3/7 activation during suppression of the anti-apoptotic proteins, such as Bcl-XL and phosphorous Akt (pAkt). The Nrf2 expression was then activated in the nuclear, indicating that the Nrf2 plays a significant role in the cytoprotective effect against the toxicity of the compounds. These results indicated that the compounds have the dual functions of a cytoprotective effect and the apoptosis induction dependent on the treated concentrations through the Nrf2 activation. In addition, the results of all the assays involved in our previous studies suggested that the metabolite FxOH having a higher activity than the Fx, will be a bioavailable compound in biological systems.

Antioxidant capacity and major polyphenol composition of teas as affected by geographical location, plantation elevation and leaf grade

Tea polyphenols have been a topic of discussion due to their health benefits. Nevertheless, detailed studies on the antioxidant capacity and polyphenol contents of teas in relation to factors including geographical locations, plantation elevations and leaf grades have been limited. In this study, 53 tea samples were analysed to determine the individual and total catechin and theaflavin contents by HPLC and the total antioxidant capacity by Oxygen Radical Absorbance Capacity (ORAC) methods. Results show that the polyphenol (catechins and theaflavins) contents were significantly influenced by plantation location. Black tea from low plantation elevation contained 22–28% more polyphenols than those from high elevation. Small tea leaves had up to 15% more polyphenols than larger leaves from similar elevation. The results were further confirmed by Principal Composition Analysis (PCA), which grouped the black and green tea samples into 3 different clusters, respectively.

Persimmon-derived tannin has bacteriostatic and anti-inflammatory activity in a murine model of Mycobacterium avium complex (MAC) disease.

Nontuberculous mycobacteria (NTM), including Mycobacterium avium complex (MAC), cause opportunistic chronic pulmonary infections. Notably, MAC susceptibility is regulated by various factors, including the host immune system. Persimmon (Ebenaceae Diospyros kaki Thunb.) tannin is a condensed tannin composed of a polymer of catechin groups. It is well known that condensed tannins have high antioxidant activity and bacteriostatic properties. However, it is hypothesized that condensed tannins might need to be digested and/or fermented into smaller molecules in vivo prior to being absorbed into the body to perform beneficial functions. In this study, we evaluated the effects of soluble persimmon-derived tannins on opportunistic MAC disease. Soluble tannins were hydrolyzed and evaluated by the oxygen radical absorbance capacity (ORAC) method. The ORAC value of soluble tannin hydrolysate was approximately five times greater than that of soluble tannin powder. In addition, soluble tannin hydrolysate exhibited high bacteriostatic activity against MAC in vitro. Furthermore, in an in vivo study, MAC infected mice fed a soluble tannin-containing diet showed significantly higher anti-bacterial activity against MAC and less pulmonary granuloma formation compared with those fed a control diet. Tumor necrosis factor α and inducible nitric oxide synthase levels were significantly lower in lungs of the soluble tannin diet group compared with the control diet group. Moreover, proinflammatory cytokines induced by MAC stimulation of bone marrow-derived macrophages were significantly decreased by addition of soluble tannin hydrolysate. These data suggest that soluble tannin from persimmons might attenuate the pathogenesis of pulmonary NTM infection.

Dietary total antioxidant capacity and incidence of chronic kidney disease in subjects with dysglycemia: Tehran Lipid and Glucose Study.

We aimed to investigate the association of dietary total antioxidant capacity (TAC) with incidence of CKD in subjects with dysglycemia. We followed-up 1179 subjects aged ≥30years with dysglycemia from the Tehran Lipid and Glucose Study (TLGS) for 3years, who were initially free of CKD. Dietary intakes of TAC, vitamin C, vitamin E, and β-carotene were assessed by a food-frequency questionnaire at the baseline. Dietary TAC was estimated using the oxygen radical absorbance capacity method. Estimated glomerular filtration rate (eGFR) was calculated, using the Modification of Diet in Renal Disease Study equation and CKD was defined as eGFR <60mL/min/1.73m2. Odds ratios (ORs) using multivariable logistic regression were reported for the association of incident CKD with dietary TAC. A total of 197 (16.7%) cases of incident CKD were recorded after 3years of follow-up. After adjustment for age, sex, smoking, physical activity, body mass index, hypertension, and total energy intake, the top tertile of dietary TAC compared to the bottom was associated with 39% [95% confidence interval (CI)=0.40-0.93] lower risk of incident CKD (P for trend=0.025). Furthermore, the highest tertile of vitamin C intake compared to the lowest risk of incident CKD was decreased (OR 0.60; 95% CI 0.38-0.93, P trend 0.023). Intakes of vitamin E and β-carotene were not significantly associated with incident CKD risk. Our findings suggest that diets high in TAC are associated with a lower risk of incident CKD among subjects with hyperglycemia after 3years of follow-up.

Antioxidant Properties of Selenophene, Thiophene and Their Aminocarbonitrile Derivatives.

The oxygen radical absorbance capacity (ORAC) method was used to detect the antiperoxyradical ability of organoselenium compounds: selenophene and its derivative, 2-amino-4,5,6,7-tetrahydro-1-selenophene-3-carbonitrile (ATSe); while as a comparison, the sulfur-containing analogue of selenophene—thiophene and its derivative—2-amino-4,5,6,7-tetrahydro-1-thiophene-3-carbonitrile (ATS)—was selected. Cyclic voltammetry (CV), differential pulse voltammetry (DPV) and squarewave voltammetry (SWV) methods were used to determine the redox characteristics of organoselenium and organosulfur compounds. The antiradical activity and capacity of the studied compounds were also measured by using stable radical 2,2ʹ-diphenyl-1-picrylhydrazyl (DPPH). Detected anodic peaks of the oxidation of selenophene, thiophene and their derivatives in CV, DPV and SWV in the interval of −1200 ÷ (+1600) mV potentials in regard to the Ag/Ag+ medium of acetonitrile prove the presence of antiperoxyradical activity in regard to oxidizers, i.e., peroxyradicals. The chemical mechanism of the antiperoxyradical ability of selenophene, thiophene and their organic derivatives is proposed.

Dietary total antioxidant capacity in early school age and subsequent allergic disease.

SummaryBackgroundDietary antioxidant intake has been hypothesized to influence the development of allergic diseases; however, few prospective studies have investigated this association.ObjectiveOur aim was to study the association between total antioxidant capacity (TAC) of the diet at age 8 years and the subsequent development of asthma, rhinitis and sensitization to inhalant allergens between 8 and 16 years, and to assess potential effect modification by known risk factors.MethodsA total of 2359 children from the Swedish birth cohort BAMSE were included. Dietary TAC at age 8 years was estimated by combining information on the child's diet the past 12 months from a food frequency questionnaire with a database of common foods analysed with the oxygen radical absorbance capacity method. Classification of asthma and rhinitis was based on questionnaires, and serum IgE antibodies were measured at 8 and 16 years.ResultsA statistically significant inverse association was observed between TAC of the diet and incident sensitization to inhalant allergens (adjusted odds ratio: 0.73, 95% confidence interval: 0.55–0.97 for the third compared to the first tertile, P‐value for trend = 0.031). Effect modification by traffic‐related air pollution exposure was observed, with a stronger association between dietary TAC and sensitization among children with low traffic‐related air pollution exposure (P‐value for interaction = 0.029). There was no evidence for effect modification by GSTP1 or TNF genotypes, although these results should be interpreted with caution. No clear associations were observed between TAC and development of rhinitis or asthma, although a significant inverse association was observed for allergic asthma (OR adj 0.57, 95% CI 0.34–0.94).Conclusions and Clinical RelevanceHigher TAC of the diet in early school age may decrease the risk of developing sensitization to inhalant allergens from childhood to adolescence. These findings indicate that implementing an antioxidant‐rich diet in childhood may contribute to the prevention of allergic disease.

Antioxidant Compound Extraction from Maqui (Aristotelia chilensis [Mol] Stuntz) Berries: Optimization by Response Surface Methodology

The optimum conditions for the antioxidant extraction from maqui berry were determined using a response surface methodology. A three level D-optimal design was used to investigate the effects of three independent variables namely, solvent type (methanol, acetone and ethanol), solvent concentration and extraction time over total antioxidant capacity by using the oxygen radical absorbance capacity (ORAC) method. The D-optimal design considered 42 experiments including 10 central point replicates. A second-order polynomial model showed that more than 89% of the variation is explained with a satisfactory prediction (78%). ORAC values are higher when acetone was used as a solvent at lower concentrations, and the extraction time range studied showed no significant influence on ORAC values. The optimal conditions for antioxidant extraction obtained were 29% of acetone for 159 min under agitation. From the results obtained it can be concluded that the given predictive model describes an antioxidant extraction process from maqui berry.

Effect of grape juice consumption on antioxidant activity and interleukin-6 concentration in lactating rats.

This study evaluated the effect of grape juice consumption on the antioxidant capacity and the interleukin-6 blood level of lactating rats. Eighteen Wistar rats, lactating females adult, were divided into two groups: control group (CG) and grape juice group (GJG). The antioxidant activity was determined by the method of 2,2-diphenyl-1-picrylhydrazyl (DPPH)-kidnapping of free radicals (DPPH) and oxygen radical absorbance capacity (ORAC), and the interleukin-6 was determined by Enzyme-Linked Immunosorbent Assay (ELISA) method. The data were presented as mean and standard deviation. The antioxidant capacity was higher (p < 0.05) in the GJG (25.00 ± 3.08 µmol eq. Trolox/g) than in the CG (10.00 ± 3.11 µmol eq. Trolox/g), by the ORAC method. The interleukin-6 (pg/ml) level was lower in the grape juice group than in CG. The consumption of grape juice during lactation improves the antioxidant capacity in lactating rats and seems capable to decrease the inflammatory activity.

Isosweetness concentrations of sucrose and high‐intensity sweeteners and antioxidant activity in white chocolate with functional properties

SummaryHealthier food products are an emerging trend in consumer demand. In this context, this study aimed at producing a prebiotic white chocolate with addition of an antioxidant source [goji berry (GB)] and replacement of sucrose by high‐intensity sweeteners (sucralose and rebaudioside A). The ideal sucrose level in white chocolate was determined as 40.46% (w/w). Different concentrations of dried GB (3%, 6% and 9%, w/w) in white chocolate did not affect consumers' preference. The isosweetness concentrations of the sweeteners were 0.05% for sucralose and from 0.10% to 0.16% (w/w) for rebaudioside A in prebiotic white chocolates. However, among the prebiotic chocolates containing GB, sucralose was the best sucrose substitute. The prebiotic white chocolates with GB showed antioxidant activity up to three times higher than the samples without the dried fruit, determined by ferric reducing antioxidant power and oxygen radical absorbance capacity methods. GB contributed to enhancing the nutritional value of white chocolate.

New Sulphated Flavonoids from Tamarix africana and Biological Activities of Its Polar Extract.

The phytochemical investigation of Tamarix africana Poir. (Tamaricaceae) shoot polar extract afforded three new sulphated flavonoids, (2S,4R)-5,7,4'-trihydroxyflavan-4-ol 5,7-disulphate (1), (2S)-5,7,4'-trihydroxyflavan 7-O-sulphate (2), and (2S)-naringenin 4'-O-sulphate (3), together with ten known compounds. Their structures were determined by spectroscopic methods including 1D and 2D NMR analysis and HRMS. Biological activities of the polar extract of T. africana shoots related to its phenolic content were also investigated. A high total phenolic content (151.1 mg GAE/g) was found in the methanol shoot extract, which exhibits strong antioxidant activities using the oxygen radical absorbance capacity method and a skin cell-based assay. Moreover, the shoot extract showed significant anti-inflammatory activity, reducing nitric oxide release by 53.5 % at 160 µg/mL in lipopolysaccharide-stimulated RAW 264.7 macrophages. Finally, T. africana shoot extract inhibited the growth of A-549 lung carcinoma cells, with an IC50 value of 34 µg/mL.

Geographic origin influences the phenolic composition and antioxidant potential of wild Crataegus monogyna from Spain

Context: Crataegus monogyna Jacq L. (Lind.) (Rosaceae) is used in folk medicine as a sedative, aerial parts being rich in polyphenols with antioxidant ability.Objectives: To study the variation in polyphenolic composition and antioxidant ability of spontaneous samples of C. monogyna in order to assess the relationship among these variables.Materials and methods: Aerial parts of C. monogyna were collected from nine different locations in central Spain and extracted with methanol after drying. Total polyphenols were determined by the Folin-Ciocalteu method using gallic acid (GA) as standard. Sixteen polyphenolic compounds (11 flavonoids and 5 phenolic acids) were identified and quantified by reversed-phase HPLC in one single analysis. The antioxidant ability was evaluated by the oxygen radical absorbance capacity (ORAC) and the free radical scavenging activity (DPPH) methods. Linear correlation analysis was used to explore the relationships between the studied variables.Results: Total polyphenol content ranged between 117.729 ± 0.011 and 204.286 ± 0.015 mg GAE/g extract, depending on the geographic origin. No relationship was found between total polyphenols and antioxidant ability by the ORAC or DPPH methods. Chromatographic analysis yielded lower amounts of polyphenols (23.3–143.26 mg/kg), as only flavonoids and phenolic acids were quantified. All the samples exhibited antioxidant activity between 1.32 ± 0.08 and 2.76 ± 0.007 μmol Trolox equivalents/mg and IC50 from 0.82 ± 0.10 to 3.76 ± 0.67 μg/mL.Conclusion: A statistically significant relationship between flavonoids and phenolic acids content and the antioxidant potential obtained by the ORAC method for C. monogyna samples was proven.