Photochemiluminescence Research Articles

Comparison of methods for evaluation of the antioxidant capacity and phenolic compounds in common spices

The present study investigates the antioxidant capacity (AC) of ethanol and ethanol/water (1:1, v/v) extracts of selected spices, using cyclic voltammetry (CV), spectrophotometric and photochemiluminescence (PCL) methods. The ABTS test was used for the measurement of the scavenging capacity of the extracts against 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulphonate) radical cations whilst a photochemiluminescence technique was employed to measure the scavenging capacity against superoxide anion radicals (O2−). The cyclic voltammetry (CV) method provided the reducing capacity values of spices. The total phenolics (TPC) and total flavonoids (TF) were determined in both types of spice extracts.With the exception of vanilla, ethanol/water (1:1, v/v) was a better extraction solvent of TPC and TF in all spices when compared to ethanol alone. The order of AC values of spices determined by the applied methods was as follows: ABTS test > PCL assay > CV method. The obtained results were useful for classification of the tested spices into groups with high antioxidant capacity (clove, cinnamon and allspice), middle (star anise and nutmeg) and low AC (anise, ginger, vanilla, fennel, cardamom, white pepper and coriander). In conclusion, these findings may be useful for the selection of spices for further applications in different food formulations to support their function as antioxidants.

Dualistic Properties of Cosmetic Formulations Based on Phenylpropanoids from <i>Ajuga reptans</i>

Our continued interest in the research and development of cosmetic active ingredients deriving from natural sources led us to investigate the potential of a purified extract of Ajuga reptans, a plant belonging to the family Labiatae and known for its traditional use in skin healing. The extracts deriving from a biotechnology platform are composed by meristematic cell culture, developed in the frame of a NTFP (non-timber forest product) project, and characterized by high content in phenylpropanoid, of which teupolioside represents the majority component. The latter is a phenylpropanoid glucoside, structurally correlated echinacoside and known in the literature for the antioxidant properties. This study was conducted with the purpose of evaluating the applicability of the Ajuga reptans extract within different cosmetic formulations. In particular, Photochemiluminescence (PCL) was used to proof the antioxidant capacity of cosmetic formulations containing the product, in relation to the change of the title of teupolioside. Furthermore, UVA and UVB filtering properties were also investigated. The results of the study showed relevantly antioxidant capacity of the finished formulation against superoxide anion, which is the main reactive oxygen species responsible for skin aging and significant synergic capacities to filter UV radiation.

Protective effect of zinc on cadmium embryotoxicity and antioxidant status of blood plasma in newly hatched chicks

Among the multiple mechanisms of cadmium toxicity proposed, the most common is the disruption of the cellular antioxidant system, which may be limited by pre- or co-treatment with zinc. The aim of this study was to determine if simultaneous zinc supplementation of hen's egg could reduce embryotoxic effect of cadmium. Egg albumen was injected on day 4 of incubation with cadmium alone (50 nmol per egg) or in combination with zinc (100 and 500 nmol). Hatching results and antioxidant activity in plasma of newly hatched chicks were determined by photochemiluminescence (PCL) and FRAP methods. Administration of cadmium markedly reduced hatchabilty (30.2 %), while both zinc doses used were embryotoxic (43.2 and 48.9 %) as compared to the control group (61.9 %). This adverse effect was reduced by simultaneous zinc administration (completely at 10-fold higher molar concentration). This observation was confirmed by examination of the antioxidant capacity in plasma of Cd-treated chicks. A slight decrease in the hydrophilic and lipophilic antioxidant capacity induced by cadmium was compensated by a co-treatment with higher zinc dose administration, whereas the exposure of hen embryos to zinc caused an increase in antioxidant potential in the plasma of chicks. It is concluded that Zn supply in conditions of exposure to Cd can protect against Cd-induced oxidative stress in chicken embryos.

A Comparative Study of the Analysis of Antioxidant Activities of Liquid Foods Employing Spectrophotometric, Fluorometric, and Chemiluminescent Methods

The antioxidant profile of liquid foods is complex and includes different lipid and water-soluble compounds. These should be considered when assessing total antioxidant capacity (TAC) of these beverages, since it may act synergistically rather than individually. This study describes and compares the use of spectrophotometric methods (Trolox equivalent antioxidant capacity, TEAC and 2,2-diphenyl-1-picrylhydrazyl, DPPH), fluorometric (oxygen radical antioxidant capacity, ORAC), and photochemiluminescence (PCL) for the measurement of the TAC of different liquid foods (fruit juice mixed with milk and vegetables beverage). An evaluation was also made for the influence of certain compounds (ascorbic acid, phenolic compounds, total carotenoids, and tocopherols) with antioxidant capacity that was present in the samples studied. The different methods studied allow the determination of the TAC of the analyzed foods in a precise and accurate way. The TAC values in the studied samples differ from the applied method. An overall antioxidant potency composite index was calculated by assigning each test's equal weight. When an index score was applied, ORAC method had the higher antioxidant capacity values in the analyzed liquid foods in comparison with the other methods. The correlations among the different methods used for the determination of the antioxidant capacity depend on food, that is, mainly due to compounds (lipid and water soluble) of the different food matrix. In addition, ascorbic acid was the main contributor to antioxidant capacity of fruit juice mixed with milk beverages measured with the different methods. However, in vegetables beverages, phenolic compounds were found to correlate more significantly with antioxidant capacity values.

Antiproliferative Activity of Pomiferin in Normal (MCF-10A) and Transformed (MCF-7) Breast Epithelial Cells

Pomiferin and osajin are prenylated isoflavones from Osage orange fruit that both have potent antioxidant activity in a variety of assays. Pomiferin, in particular, has strong activity against the superoxide anion in a photochemiluminescence (PCL) assay system. In vitro, pomiferin, but not osajin, demonstrated selective antiproliferative activity against the tumorigenic breast epithelial cell line MCF-7 (IC(50) = 5.2 μM) with limited toxicity toward nontumorigenic breast epithelial cells (MCF-10A). The differential sensitivity of normal and tumorigenic cells to the antiproliferative action of pomiferin was examined further by using cDNA microarrays. With a stringent cutoff of p < 0.01, a total of 94 genes were significantly differentially expressed between MCF-7 and MCF-10A cells; 80 up-regulated and 14 down-regulated when cells were exposed to 5 μM pomiferin for 24 h. Fold changes by microarray analysis were confirmed using RT-qPCR, and the most significant changes were found with genes related to antioxidant enzymes. Genes involved in mitotic inhibition and apoptotic regulations were also found to be up-regulated. Pomiferin is therefore a good anticancer candidate agent that may be useful either alone or in combination with other therapeutic agents and, because of its selectivity toward tumor cells, likely to have fewer side effects that classic chemotherapy drugs.

Antioxidant capacity of a new crispy type food products determined by updated analytical strategies

The updated analytical strategies were employed to determine the antioxidant capacity of hydrophilic and lipophilic extracts of a new crispy type food products such as crunchy apple slices, crunchy apple slices with cinnamon, crunchy beetroot slices with vinaigrette taste, crunchy carrot slices and crunchy tomato slices. The total antioxidant capacity (TAC) was calculated as a sum of the antioxidant capacity of hydrophilic and lipophilic extracts originating from the sample. Antioxidant capacity was measured directly by cyclic voltammetry (CV), against 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulphonate) radical cation (ABTS+) and 2,2-diphenyl-1-picrylhydrazyl radical (DPPH), and by photochemiluminescence (PCL) assay against superoxide anion radical (O2-·). The total polyphenol content in hydrophilic extracts was measured with Folin–Ciocalteu’s reagent. The rank of TAC obtained with updated analytical strategies was as follows: crunchy beetroot slices with vinaigrette taste>crunchy apple slices with cinnamon≈crunchy apple slices>>>crunchy tomato slices>crunchy carrot slices. The values of TAC determined by CV method were comparable with those provided by DPPH assay but they were twofold lower than those obtained by ABTS and PCL assay. The CV assay highly correlated with ABTS and PCL methods (r=0.99). The applied updated analytical strategy for determination of the antioxidant capacity proved to be useful tool for screening new crispy type food products.

Antioxidant activity of hydroxytyrosol in frankfurters enriched with n-3 polyunsaturated fatty acids

The capacity of hydroxytyrosol (HXT) to inhibit lipid oxidation in cooked pork meat batter, oil-in-water emulsions and potential functional frankfurters formulated with a healthier oil combination (as animal fat replacer) was studied during chilling storage, and its effect compared with those produced by synthetic antioxidants (BHA/BHT). Although efficiency varied, HXT was an effective antioxidant during chilling storage in the three food matrices studied. In general the order of inhibition capacity of HXT against lipid oxidation (thiobarbituric acid-reactive substances-TBARS) was cooked meat batter>oil-in-water emulsion>frankfurters, whereas in the case of BHA/BHT (with lower inhibitory activity than HXT) it was cooked meat batter>oil-in-water emulsion, and there was no antioxidative effect in frankfurters. Whereas significant correlations were established between lipid oxidation (TBARS) and antioxidative capacity measured by photochemiluminescence (PCL) in frankfurters supplemented with HXT and BHA/BHT, no significant correlations were found between ferric reducing/antioxidant power assay (FRAP) and TBARS and PCL.

Chemical Characterization (GC/MS and NMR Fingerprinting) and Bioactivities of South‐African Pelargonium capitatum (L.) L' Her. (Geraniaceae) Essential Oil

Chemical fingerprinting of commercial Pelargonium capitatum (Geraniaceae) essential oil samples of south African origin was performed by GC, GC/MS, and (13) C- and (1) H-NMR. Thirty-seven compounds were identified, among which citronellol (32.71%) and geraniol (19.58%) were the most abundant. NMR Spectra of characteristic chemicals were provided. Broad-spectrum bioactivity properties of the oil were evaluated and compared with those of commercial Thymus vulgaris essential oil with the aim to obtain a functional profile in terms of efficacy and safety. P. capitatum essential oil provides a good performance as antimicrobial, with particular efficacy against Candida albicans strains. Antifungal activity performed against dermatophyte and phytopathogen strains revealed the latter as more sensitive, while antibacterial activity was not remarkable against both Gram-positive and Gram-negative bacteria. P. capitatum oil provided a lower antioxidant activity (IC(50) ) than that expressed by thyme essential oil, both in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and β-carotene bleaching tests. Results in photochemiluminescence (PCL) assay were negligible. To test the safety aspects of P. capitatum essential oil, mutagenic and toxicity properties were assayed by Ames test, with and without metabolic activation. Possible efficacy of P. capitatum essential oil as mutagenic protective agent against NaN(3) , 2-nitrofluorene, and 2-aminoanthracene was also assayed, providing interesting and significant antigenotoxic properties.

Ergosterol Profiles, Fatty Acid Composition, and Antioxidant Activities of Button Mushrooms as Affected by Tissue Part and Developmental Stage

This article investigated the mycochemical profiles and the antioxidant activities of the lipophilic extracts of the white and brown button mushrooms. We found that only free ergosterols were present in both mushrooms at 2.04-4.82 mg/g dry matter (DM). Ergosterol concentration was higher in early growth stages but decreased as the mushrooms grew, and it distributed evenly between the caps and stems during early developmental stages but accumulated more in the caps after maturation. The photochemiluminescence (PCL) values of the two mushrooms were 5.49-10.48 nmol trolox equivalent/mg DM, and the EC50 values of 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay ranged 20.19-41.49 mg DM/μg DPPH. The ergosterol content positively correlated with the antioxidant activities (r2>0.89). The total fatty acid content was 8.7 mg/g DM in the white and 5.1 mg/g DM in the brown button mushroom and contained mainly linoleic, palmitic, and stearic acids. Our data provide guidance for optimized harvesting time of mushrooms and maximized health benefits.

Evaluation of In vitro Antioxidant Activity of Some Plants of Cachar District, Assam.

The present study was undertaken to evaluate in vitro antioxidant activity of methanolic extract from leaves of four plants viz. Clerodendron colebrookianum Walp. (Verbinaceae), Gnetum gnemon L. (Gnetaceae), Sarcochlamys pulcherrima (Roxb.) Gaud. (Urticaceae), Garcinia lancifolia (Don) Roxb. (Cluciaceae), from Cachar district, Assam, India. DPPH (1,1-diphenyl 2-picrylhydrazyl) radical scavenging capacity, reducing power assay (RPA) and photochemiluminescence (PCL) assay were used for evaluating in vitro antioxidant activity. Total phenolic content (TPC) was estimated by Folin-Ciocalteu's method. Sarcochlamys pulcherrima showed highest antioxidant activity (DPPH EC50 9.70 ±1.51ppm), as compared to C. colebrookianum (121.05 ±1.09ppm), G. gnemon (255.99 ±0.82ppm), and G. lancifolia (344.96 ±0.76ppm). Highest activity of S. pulcherrima was also supported by RPA and PCL and highest TPC (0.33 mg gallic acid equivalent/mg of dry extract) amongst the plants, indicated that phenolic compound are mainly responsible for the activity.

In‐vitro study on the efficacy of tannin fractions of edible nuts as antioxidants

AbstractTannin fractions were isolated from crude acetonic extracts of defatted walnut, hazelnut and almond kernels using Sephadex LH‐20 column chromatography. The obtained material was characterized by content of total phenolics and electrophoretic separations using capillary zone electrophoresis (CZE). The antioxidant activities of the tannin fractions were analyzed by several methods: DPPH and ABTS assays, photochemiluminescence (PCL) method, as well as in two lipid model systems: emulsion with β‐carotene‐linoleic acid and L‐α‐lecithin liposomes. The contents of total phenolics in the tannin fractions of walnuts, hazelnuts and almonds were 550, 329 and 83 mg catechin eq/g, respectively. The electrophoretic profiles of hazelnut and almond tannin fractions were similar, in contrast to the walnut profile. All analyzed fractions exhibited strong antioxidant properties. The antioxidant capacity of lipid‐soluble (ACL) compounds determined by PCL method was the highest for the fraction isolated from walnuts – 7.35 mmol Trolox eq/g. The DPPH radical and the ABTS radical cation were scavenged by the walnut tannin fraction with a higher efficacy than by the two other fractions. EC50 values of the DPPH method were 1.8 times higher for the hazelnut fraction and 2.3 times higher for the almond fraction when compared to the walnut tannins. In turn, the total antioxidant activity values were 8.17, 2.82 and 1.98 mmol Trolox eq/g for the walnut, hazelnut and almond fractions, respectively. On the other hand, in both lipid models applied, lower antioxidant activity of walnut tannins than of hazelnut tannins was noted. The antioxidant effect of almond tannins was weaker or similar than that of walnut tannins in the β‐carotene‐linoleic acid emulsion and the L‐α‐lecithin liposomal system, respectively.

Antioxidant activity of phytogenous industrial waste and derived extracts for the production of feed and food additives

SummaryOrganic wastes as well as their ethanolic, water and heptane extracts and fermented products derived from herbs, fruit and vegetables obtained worldwide from food and pharmaceutical industries were investigated regarding their antioxidant activities using different methods [1.1‐diphenyl‐2‐picrylhydrazyl, FeIII‐reduction method and photochemiluminescence (PCL)]. The highest antioxidative activities were exhibited by different products of grape seed wastes (350–830 mg rosmarinic acid equivalent g−1 dried material = rae g−1 dm) followed by ethanolic extracts of blueberry (475 mg rae g−1 dm), larch (219 mg rae g−1 dm), willow (193 mg rae g−1 dm) and sunflower presscake (154 mg rae g−1 dm). Ethanolic extracts of the residues showed comparatively higher activity than water extracts. The least antioxidative capacities were found in heptane extracts of serenoa products (0.4; 0.6 mg rae g−1 dm) and fermented waste of carrots (1.6 mg rae g−1 dm). Correlating different assay methods, the strongest correlation was found between FeIII‐reduction and DPPH‐method (correlation coefficient r2 = 0.99**) and the weakest between FeIII‐reduction and PCL method (r2 = 0.57**) for raw materials.

Characteristics of flaxseed hull oil

Oils from two commercial flaxseed hulls extracted by six procedures were evaluated for physicochemical characteristics. Oil yield ranged from 9% to 28% depending on solvent and extraction. Lipid fractionation of crude flaxseed hull oil yielded 92.5% neutral lipids, 3.1% phospholipids, 2.4% acidic lipids and 2.1% free fatty acids. Flaxseed hull oil exhibited three thermal transitions between −35 and −13 °C with solvent dependent polymorphism. Thermal oxidation by differential scanning calorimetry (DSC) revealed three step oxidation of flaxseed hull oil with mean onset and oxidation temperatures at 121 and 150–253 °C, respectively depending on the extraction procedure. Flaxseed hull oil exhibited two-fold difference (0.6–1.2 μm Trolox equivalent/g) in antioxidant activity measured by a photochemiluminescence (PCL) assay. Supercritical CO 2 extracted the most oil with the highest antioxidant capacity of all evaluated procedures resulting in a defatted flaxseed hull containing the highest (53 mg/g) secoisolariciresinol diglucoside (SDG) level.

Evaluation of the antioxidant capacity of lupin sprouts germinated in the presence of selenium

Antioxidant capacity of 5 DAS (days after seeding) lupin sprouts germinated in the presence of selenate or selenite was determined by cyclic voltammetry (CV), Folin-Ciocalteu reagent (FCR) application and photochemiluminescence (PCL) methods. The hydrophilic (80% methanol) and lipophillic (hexane/methanol) extracts of 5 DAS lupin sprouts germinated in the absence of selenium (control sprouts) showed higher antioxidant capacity than ungerminated seeds. Five DAS sprouts produced in the presence of higher concentration of selenate or selenite (6–8 mg/L) showed increased total antioxidant capacity formed by both hydrophilic and lipohillic antioxidants when evaluated by CV and FCR methods. The hydrophilic extracts from sprouts produced in the presence of low concentration of selenate (2–6 mg/L) showed a significantly higher antioxidant capacity of water-soluble compounds (PCL ACW) while no changes were noted in those germinated in the presence of the highest concentration in relation to the control sprouts. In contrast, the antioxidant capacity of lipid-soluble compounds (PCL ACL) lowered significantly in relation to the control sprouts. The similar changes in antioxidant capacity of sprouts produced in the presence of selenite were found by both PCL assays. Comparison of PCL with CV and FCR reducing capacity assays has shown that these methods yielded considerably different chemical information. Moreover, the changes in total antioxidant and total reducing capacity of sprouts germinated in the presence of either selenate or selenite provided by CV and FCR assays were higher than those obtained by photochemiluminesce measurements. It can be suggested to use 6–8 mg/L of selenite rather than selenate in order to obtain a lupin sprouts with high antioxidant capacity.

Determination of the Relative Contribution of Quercetin and Its Glucosides to the Antioxidant Capacity of Onion by Cyclic Voltammetry and Spectrophotometric Methods

This paper describes the use of cyclic voltammetry (CV), spectrophotometric methods [Trolox equivalent antioxidant capacity (TEAC), peroxyl radical trapping capacity (PRTC), DPPH radical scavenging activity (RSA), and Folin-Ciocalteu reagent (FCR) reducing capacity], and photochemiluminescence (PCL) for the measurement of the antioxidant capacity of onion var. Sochaczewska and var. Szalotka. The antioxidant and reducing activity of the dominant onion flavonoids quercetin (Q), quercetin-3- O-beta-glucoside (Q3G), quercetin-4'- O-beta-glucoside (Q4'G), and quercetin-3,4'-di- O-beta-glucoside (Q3,4'G) were determined by spectrophotometric (TEAC and PRTC) and CV methods, respectively. The contribution of quercetin and its glucosides to the antioxidant capacity of onion was calculated in consequence of the qualitative and quantitative analysis of onion flavonoids by high-performance liquid chromatography-ultraviolet-mass spectrometry. The dominant forms of quercetin in the onion var. Sochaczewska and Szalotka included Q4'G (61 and 54%), Q3,4'G (37 and 44%), Q3G (1.4 and 1.1%), and free quercetin (1.1 and 0.7%), respectively. The CV experiment showed the highest reducing activity of Q while Q3G, Q4'G, and Q3,4'G exhibited about 68, 51, and 30% of the reducing power noted for Q. The order of the reducing activity of onion flavonoids was confirmed by their free radical scavenging activity and evaluated by TEAC and PRTC assays as follows: Q > Q3G > Q4'G > Q3,4'G. The Q4'G and Q3,4'G showed poor antioxidant activity under both applied spectrophotometric assays but still exhibited reducing activity based on CV experiments. The reducing capacity of onions determined by CV method was twice higher than the antioxidant capacity formed by water-soluble compounds (ACW) evaluated by PCL, and it was about 50% higher than PRTC and DPPH RSA results and the converted FCR reducing capacity. In contrast, the reducing capacity of onions determined by the CV method was 3-fold and about four times lower when compared to the antioxidant capacity evaluated by the TEAC method and that formed by lipid-soluble compounds (ACL) provided by PCL, respectively. The highest antioxidant capacity of onion was found under cumulative consideration of PCL (ACW + ACL) and TEAC assays. The relative contribution of Q and its glucosides to the antioxidant capacity of onions showed a low contribution of Q, Q3G, and Q3,4'G derived from CV, TEAC, and PRTC assays while the highest contribution to the antioxidant capacity of onions was provided by Q4'G.

천연 암반 심해수의 항산화 활성 및 면역반응에 대한 연구

Korean Deep ground sea-like water (KDSW) has a similar mineral composition with deep sea water. KDSW has demonstrated its usefulness and attracted in the medical fields. KDSW and Danasoo (desalted deep ground sea-like water) intake improve antioxidant, antidiabetic activity and immunity. Antioxidant activities of KDSW and Dnansoo were measured by using 2,2-diphenyl-l-picryl-hydrazyl (DPPH) free radical, superoxide dismutase-like activity (SODA) and photochemiluminescence (PCL). DPPH radical scavenging and SOD-like activities of KDSW and Danasoo were remarkably increased in a dose-dependent manner. Antioxidant activities of KDSW and Danasoo 85.32 and 14.02 nmol of ascorbic acid equivalent/ml KDSW and Danasoo, respectively, using the PCL method. Lipopolysaccharide (LPS)-induced nitric oxide (NO) production in macrophages RAW264.7 cells was inhibited up to 30% by treatment with Danasoo (20%). NO is synthesized by the enzyme of nitric oxide synthase (NOS) and plays an important role tumor growth and angiogenesis. The anticancer effects of Danasoo on human gastric and lung cancer cells was performed by levels of inducible nitric oxide synthase (iNOS). Danasoo significantly reduced iNOS expression of human gastric cancer (SNU-l) and lung carcinoma (A549). The serum glucose level was significantly reduced by Danasoo (20%) diet in streptozotocin (STZ)-induced diabetic rats. These result suggest that KDSW has excellent biological activities and thus it has great potential as a source for natural health products.

Flavonoid content and antioxidant capacity of spinach genotypes determined by high‐performance liquid chromatography/mass spectrometry

AbstractBACKGROUND: Flavonoids in different spinach genotypes were separated, identified, and quantified by a high‐performance liquid chromatographic method with photodiode array and mass spectrometric detection. The antioxidant capacities of the genotypes were also measured using two antioxidant assays–oxygen radical absorbance capacity (ORACFL) and photochemiluminescence (PCL)–which measure the response to the peroxyl and superoxide anion radicals, respectively.RESULTS: Eighteen flavonoids representing glucuronides and acylated di‐ and triglycosides of methylated and methylene dioxide derivatives of 6‐oxygenated flavonols were identified (patuletin, spinacetin, spinatoside, jaceidin). The total flavonoids ranged from 1805 to 3703 mg kg−1, indicating 2.0‐fold variation among genotypes. The ORACFL and PCL values ranged from 48.7 to 84.4 mmol kg−1 and from 9.0 to 14.0 mmol kg−1, respectively, representing as much as 1.7‐fold variation among genotypes.CONCLUSION: The ORACFL and PCL values were highly correlated with total flavonoid content (rxy = 0.96). Copyright © 2008 Society of Chemical Industry

Processing and Storage Effects on Monomeric Anthocyanins, Percent Polymeric Color, and Antioxidant Capacity of Processed Blackberry Products

Blackberries are a rich source of polyphenolics, particularly anthocyanins, that may contribute to the reduced risk of chronic disease; however, as with most berries, the fresh fruit are only seasonally available. With most of the blackberries consumed as frozen or in thermally processed forms after long-term storage, the purpose of this study was to evaluate the effects of processing and 6 months of storage on the anthocyanins and antioxidant capacity of blackberries that were individually quick-frozen (IQF), canned-in-syrup, canned-in-water, pureed, and juiced (clarified and nonclarified). Monomeric anthocyanins, percent polymeric color, and antioxidant capacity by oxygen radical absorbance capacity (ORAC FL) and photochemiluminescence (PCL) were determined postprocessing (1 day) and after 1, 3, and 6 months of storage. Processing resulted in increases in polymeric color values (up to 7%) and losses in monomeric anthocyanins (up to 65%). For most products, processing also resulted in losses in antioxidant capacity (by ORAC FL and PCL). Storage at 25 degrees C of all processed products resulted in dramatic losses in monomeric anthocyanins with as much as 75% losses of anthocyanins throughout storage, which coincided with marked increases of percent polymeric color values of these products over 6 months of storage. There were no changes in ORAC FL or PCL for processed products throughout long-term storage. No significant changes in antioxidant capacity or anthocyanin content were observed in IQF fruit during long-term storage at -20 degrees C.

Use of Cyclic Voltammetry, Photochemiluminescence, and Spectrophotometric Methods for the Measurement of the Antioxidant Capacity of Buckwheat Sprouts

This paper describes the use of cyclic voltammetry, photochemiluminescence (PCL), and spectrophotometric methods (TEAC and FCR reducing capacity) for the measurement of the antioxidant capacity of dark- and light-grown buckwheat sprouts. Moreover, the flavonoid profile of studied material is provided. Methanol extracts (80%) from ungerminated buckwheat grain and 6 and 8 DAS (days after seeding) sprouts were used. The 8 day germination period was sufficient to obtain good quality sprouts with completely removed pericarps. The ungerminated buckwheat grain contained only rutin, whereas in sprouts produced in dark or light, a high level of isoorientin, orientin, vitexin, rutin, and isovitexin was found. The flavonoid content in sprouts produced under light was almost 2 times higher than those of sprouts produced in the dark. The antioxidant capacity of light-grown sprouts was higher than that of dark-grown ones. The results from voltammetric experiments obtained for buckwheat seeds and 6 and 8 DAS sprouts harvested under dark or light conditions highly correlated with those obtained by PCL antioxidant capacity of water-soluble substances (PCL ACW) (r = 0.99), PCL antioxidant capacity of lipid-soluble substances (r = 0.99), TEAC (r = 0.99), and FCR reducing capacity (r = 0.99). The use of cyclic voltammetry, PCL ACW, and TEAC was fully applicable for the evaluation of the antioxidant capacity of buckwheat sprouts.

Antioxidant activities of ethanolic extracts from the twigs of Cinnamomum osmophloeum

Cinnamomum osmophloeum Kaneh. is an indigenous tree species in Taiwan. In this study, phytochemical characteristics and antioxidant activities of ethanolic extracts from the twigs of C. osmophloeum were investigated for the first time. The extracts were obtained successively using liquid–liquid partition to yield n-hexane (Hex), ethyl acetate (EtOAc), n-butanol (BuOH) and water fractions. The antioxidant activities of C. osmophloeum twig extracts were examined using various antioxidant assays, such as DPPH, NBT, reducing power, lipid peroxidation using mouse brain homogenates, metal chelating ability, and photochemiluminescence (PCL). In addition, total phenolic contents were also determined. Results revealed that the BuOH fraction exhibited the best performance in DPPH assay, NBT assay, reducing power assay and lipid peroxidation using mouse brain homogenates assay. Furthermore, the BuOH fraction has the highest total phenolic contents (496.7 mg of GAE/g). Consequently, kaempferol-7- O-rhamnoside was also isolated from the antioxidative BuOH fraction and its activity was also confirmed. These results demonstrated that ethanolic extracts of C. osmophloeum twigs have excellent antioxidant activities and thus it has great potential as a source for natural health products.