Antioxidant compounds and antioxidant capacity of Peruvian camu camu (Myrciaria dubia (H.B.K.) McVaugh) fruit at different maturity stages

The antioxidant capacities of ascorbic acid and phenolic compounds present in camu camu fruit were screened during ripening. Ascorbic acid decreased, and anthocyanin, flavonol and flavanol contents, and DPPH antioxidant capacity increased during ripening. Antioxidant compounds from camu camu were fractionated in two fractions: an ascorbic acid-rich fraction (F-I) and a phenolics-rich fraction (F-II). F-I was the major contributor to the DPPH antioxidant capacity (67.5–79.3%) and F-II played a minor role (20.7–32.5%). A total of 30 different phenolic compounds were detected by HPLC-PAD. The presence of catechin, delphinidin 3-glucoside, cyanidin 3-glucoside, ellagic acid and rutin was elucidated. Other phenolic compounds, such as flavan-3-ol, flavonol, flavanone and ellagic acid derivatives, were also present. For the three ripening stages the flavan-3-ols and ellagic acid group were the most representative phenolic compounds in this fruit. Acid hydrolysis of F-II revealed the presence mainly of gallic and ellagic acids, suggesting that camu camu fruit possesses important quantities of hydrolysed tannins (gallo- and/or ellagitannins). These results confirm that camu camu fruit is a promising source of antioxidant phenolics.     

Changes of phenolic acids and antioxidant activities during potherb mustard (Brassica juncea, Coss.) pickling

Phenolic acids in potherb mustard (Brassica juncea, Coss.) were determined and the effects of pickling methods on the contents of total free phenolic acids, total phenolic acids, total phenolics, and antioxidant activities were investigated. Gallic acid, protocatechuic acid, p-hydroxybenzoic acid, vanillic acid, caffeic acid, p-coumaric acid, ferulic acid, and sinapic acid were identified in the present study. The contents of total free phenolic acids, total phenolic acids and total phenolics in fresh potherb mustard were 84.8 ± 0.58 μg/g dry weight (DW), 539 ± 1.36 μg/g DW, and 7.95 ± 0.28 mg/g DW, respectively. The total free phenolic acids increased during the pickling processes, but the total phenolic acids, total phenolics, and antioxidant activities decreased. However, after 5 weeks of fermentation, all the pickling methods retained over 70% of total phenolic contents and above 65% of antioxidant capacities. The results indicated that pickling processes were relatively good methods for the preservation of phenolic acids and antioxidants for potherb mustard.     

Flavonoid constituents and their contribution to antioxidant activity in cultivars and hybrids of rabbiteye blueberry (Vaccinium ashei Reade)

Fruit from 42 blueberry (Vaccinium spp.) cultivars, including 36 rabbiteye cultivars (Vaccinium ashei Reade), three V. ashei hybrid derivatives, and three northern highbush (Vaccinium corymbosum L.) standards were evaluated for antioxidant capacity, individual flavonoid content, and the contribution of each identified phenolic compound to total antioxidant activity. Considerable variation was found in flavonoid content, antioxidant activity, and their contribution to total antioxidant activity among cultivars. Among 42 blueberry cultivars, the rabbiteye ‘Early May’ contained the highest amount of chlorogenic acid, myricetin 3-arabinoside, quercetin derivatives, and delphinidin-, cyanidin-, petunidin-, and malvidin-basis anthocyanins. ‘Early May’ cultivar also had the highest antioxidant activity (88.2 μmol TE/g fw). ‘Owen’, ‘Bluegem’, ‘Clara’, Climax’, and ‘Centurion’ were among the other rabbiteye cultivars that also had high levels of flavonoids and antioxidant activities. In contrast, the pink-fruited V. ashei hybrid, ‘Pink Lemonade’, had the lowest content of flavonoids and lowest antioxidant activity. The mean flavonoid content and antioxidant activity of rabbiteye cultivars was higher than those among northern highbush and V. ashei hybrids. The antioxidant activity of V. ashei hybrid derivatives was derived mainly from chlorogenic acid, myricetin, and quercetin, which contributed 62.5% of total antioxidant activity, whereas anthocyanins (malvidin, petunidin, delphinidin, and cyanidin) were the main contributors to the antioxidant activity of rabbiteye cultivars (76.2%) and northern highbush standards (76.8%). Blueberry cultivars identified to have high phenolic content and high antioxidant activity could be used as parents for future blueberry breeding programmes to develop new blueberry cultivars with higher antioxidant activity and further improve human health.     

薄壳山核桃油成分及抗氧化性研究

通过气相色谱法检测薄壳山核桃油中的脂肪酸组成及含量,用ABTS法测定薄壳山核桃油的抗氧化活性。结果表明:薄壳山核桃油中油酸含量最高,其次依次是亚油酸、棕榈酸、硬脂酸、亚麻酸,含量最小的是顺-11-二十碳烯酸,不饱和脂肪酸质量分数达到90%;品种ZL75的抗氧化活性最强(自由基清除率65.33%)。试验结果对抗氧化、防衰老植物的开发、利用以及薄壳山核桃优良品种的栽培和开发有一定的指导作用。     

Phenolic composition and antioxidant activity of culms and sugarcane (Saccharum officinarum L.) products

The present work reports amounts of flavonoids and phenylpropanoids of culms of three sugarcane varieties and of raw juice, syrup, molasse and VHP sugar. The antioxidant activity of those materials was evaluated by the DPPH and β-carotene/linoleic acid methods. The predominant phenolics in culms were phenylpropanoids (caffeic, chlorogenic and coumaric acids), while flavones (apigenin, tricin and luteolin derivatives) appeared in lower amounts. Differences were noted either among phenolic profiles of sugarcane culms or between culms and sugarcane products. The antioxidant activities of solutions from most samples were similar or higher than a 80 μM Trolox solution.     

Phenolics and antioxidant properties of bayberry (Myrica rubra Sieb. et Zucc.) pomace

Five cultivars of Myrica rubra, Biqi, Wandao, Dongkui, Dingao, and Zaodamei, were collected to analyze the phenolic compounds and evaluate the antioxidant properties of bayberry pomaces. The main anthocyanin was cyanidin-3-o-glucoside (3073.3–6219.2 mg/kg dry weight (DW)) and the main flavonol was quercetin-3-o-glucoside (296.2–907.9 mg/kg dry weight). Quercetin and myricetin were also found in the bayberry pomaces, and quercetin deoxyhexoside and myricetin deoxyhexoside were tentatively identified. The dominant phenolic acids were gallic acid (102.9–241.7 mg/kg dry weight) and protocatechuic acid (29.5–57.2 mg/kg dry weight). Other phenolic acids such as p-hydroxybenzoic, vanillic, caffeic, p-coumaric, and ferulic acids were also present in the bayberry pomaces, whereas, chlorogenic acid was only detected in Dongkui (1.58 mg/kg dry weight). The antioxidant activity of Wandao was the strongest of the five cultivars, whereas the activity of Dongkui was the weakest, and a significant positive relationship was observed between antioxidant activity and total phenolic content or total anthocyanins.     

Phenolic content and antioxidant capacity of tropical highland blackberry (Rubus adenotrichus Schltdl.) during three edible maturity stages

Tropical highland blackberry (Rubus adenotrichus Schltdl.) is a good source of antioxidants and contains appreciable levels of phenolic compounds, mainly ellagitannins and anthocyanins. This study examined the influence of three ripening stages on phenolic contents. Major anthocyanin pigments increased from 0.20 (red fruit) to 1.34 mg g⁻¹ fresh weight (FW) (fully ripe fruit), whereas ellagitannins and ellagic acid derivatives dropped from 3.8 to 2.2 mg ellagic acid equivalents g⁻¹ (FW). Flavonols also dropped from 5.1 to 2.0 mg quercetin equivalents 100 g⁻¹ (FW). Consequently, values for total phenolic compounds ranged from 5.8 to 5.2 mg gallic acid equivalents g⁻¹ (FW), showing no specific trend. Antioxidant activity (H-ORAC) increased from 38.29 to 64.00 μmol of Trolox equivalents g⁻¹ (FW) during ripening. When compared with other commercial cultivars, R. adenotrichus stands out for high H-ORAC value, although comparatively it possesses low anthocyanin content and average total phenolic content.     

Quantification of gallic acid and ellagic acid from longan (Dimocarpus longan Lour.) seed and mango (Mangifera indica L.) kernel and their effects on antioxidant activity

Gallic acid (GA) and ellagic acid (EA) have been identified in longan seed and mango kernel by the use of reversed-phase high-performance liquid chromatography (RP-HPLC) coupled with photodiode array detection (DAD). The ethanolic extract of longan seed contained 23.3 and 156 mg/100 seeds of GA and EA, respectively. The ethanolic extracts of mango kernel contained approximately 87% more GA than the longan seed ethanolic extracts but about 32% less EA. After heat treatment and acid hydrolysis, mango kernel had higher concentrations of GA and EA, contributing to more potent antioxidant activity. The results demonstrated rich sources of GA and EA in longan seed and mango kernel which might provide a novel source of these natural antioxidants.     

Determination of phenolic composition and antioxidant capacity of blood orange juices obtained from cvs. Moro and Sanguinello (Citrus sinensis (L.) Osbeck) grown in Turkey

The phenolic compounds and antioxidant capacities of orange juices obtained from cvs. Moro and Sanguinello (Citrus sinensis (L.) Osbeck) were determined. A high-performance liquid chromatographic method coupled with diode-array detection was used to identify and quantify phenolic compounds of the orange juices. A total of 18 phenolic compounds were identified and quantified in Moro and Sanguinello orange juices, including hydroxybenzoic acids (2), hydroxycinnamic acids (5), flavanones (5), and anthocyanins (6). It was observed that total phenolic content of Moro juice was higher than that of Sanguinello juice. Ferulic acid was the most dominant hydroxycinnamic acid and cyanidin 3-(6″-malonyl glucoside) and cyanidin 3-glucoside were the most dominant anthocyanins in both cultivars. Antioxidant activities of orange juices were measured using the DPPH^· (2,2-diphenyl-1-picrylhydrazyl) method. According to DPPH^· assays, the antioxidant capacity of Moro juice was found to be higher than that of Sanguinello juice.     

Kinetic study of the antioxidant compounds and antioxidant capacity during germination of Vigna radiata cv. emmerald, Glycinemax cv. jutro and Glycine max cv. merit

The purpose of this study was to determine the antioxidant capacity and the content of antioxidant compounds in raw mung bean seeds and sprouts (Vigna radiata cv. emmerald) germinated for 2, 3, 4, 5 and 7 days and of soybean seeds of Glycine max cv. jutro germinated for 2, 3 and 4 days and of Glycine max cv. merit germinated for 2, 3, 4, 5 and 6 days. Antioxidant compounds, such as vitamin C and E, total phenolic compounds and reduced glutathione (GSH) were studied. Antioxidant capacity was measured by superoxide dismutase-like activity (SOD-like activity), peroxyl radical-trapping capacity (PRTC), trolox equivalent antioxidant capacity (TEAC) and inhibition of lipid peroxidation in unilamellar liposomes of egg yolk phosphatidylcholine (PC). The results indicated that changes in the contents of vitamin C, vitamin E and GSH depended on the type of legume and germination conditions. Sprouts of mung bean and soybeans provided more total phenolic compounds than did raw seeds. The SOD-like activity increased after germination of mung bean seeds for 7 days, by 308%, while no change was observed in sprouts of Glycine max cv. jutro and an increase was observed after 5 and 6 days of germination (∼20%) in Glycine max cv. merit. PRTC and TEAC increased during the germination process and retentions of 28–70% and 11–14%, respectively, for soybean, and 248% and 61%, respectively, for mung bean were observed at the end of germination. The inhibition of lipid peroxidation increased by 389% in 5–7 days’ germination of Vigna radiata cv. emmerald sprouts, and 66% in Glycine max cv. merit sprouts whilst, in Glycine max cv. jutro, germination did not cause changes in lipid peroxidation inhibition. According to the results obtained in this study, germination of mung bean and soybean seeds is a good process for obtaining functional flours with greater antioxidant capacity and more antioxidant compounds than the raw legumes.     

Effect of hydrothermal treatment on the antioxidant properties of broccoli (Brassica oleracea var. botrytis italica) florets

In the extracts of fresh raw and frozen broccoli, caffeic, ferulic, sinapinic acids and kaempferol were identified. Boiling reduced the amounts of caffeic acid and kaempferol in both samples. The concentration of polyphenols was 2.69 mg/g fresh mass and 0.96 mg/fresh mass in fresh raw broccoli and frozen raw broccoli, respectively. Boiling significantly decreased the amounts of phenolic compounds in fresh broccoli (1.58 mg/g of fresh mass). In the case of frozen broccoli, boiling increased the concentration of polyphenols by 38%. Fresh broccoli extract neutralized free radicals by 19.87%. Boiling significantly reduced its antiradical activity (to 15.06%). Samples of frozen broccoli had a 27.06% antiradical ability. Boiling did not change the antiradical activity in frozen broccoli case. Hydrothermal processing significantly influenced on the ability of the extracts to inhibit the decolorization of β-carotene emulsion. The extract of fresh broccoli had a higher activity when uncooked. Boiling seemed to increase this activity in the case of frozen broccoli samples. The results of the studies on the ability of broccoli extracts to inhibit linoleic acid autooxidation were ambiguous and depended on the method applied. No correlation was found between the content of phenolic compounds and the antioxidant activity of the extracts, regardless of the experimental variant and technique used.     

Physico-chemical and antioxidant properties of four mango (Mangifera indica L.) cultivars in China

Four principal mango cultivars (Tainong No.1, Irwin, JinHwang and Keitt) grown in southern China were selected, and their physico-chemical and antioxidant properties were characterized and compared. Of all the four cultivars, Tainong No.1 had highest content of total phenols, ρ-coumaric acid, sinapic acid, quercetin, titratable acidity, citric acid, malic acid, fructose, higher antioxidant activities (DPPH, FRAP) and L^∗, lower pH, PPO activity and individual weight. Keitt mangoes showed significantly (p < 0.05) higher contents of β-carotene, ρ-hydroxybenzoic acid, sucrose, total sugar, total soluble solid, catechin, succinic acid and higher PPO activity. JinHwang mangoes exhibited significantly (p < 0.05) higher individual weight and PPO activity, but had lower content of total phenols, β-carotene and lower antioxidant activity. Principal component analysis (PCA) allowed the four mango cultivars to be differentiated clearly based on all these physico-chemical and antioxidant properties determined in the study.     

High hydrostatic pressure effect on chemical composition,color, phenolic acids and antioxidant capacity of Cape gooseberry pulp (Physalis peruviana L.)

The aim of this study was to evaluate the effects of high hydrostatic pressure (HHP) at 300, 400 and 500 MPa/1, 3 and 5 min on nutritional and antioxidant properties of Cape gooseberry pulp after immediate application and after 60 days of storage. Proximal analysis, color, phenolic acids content and antioxidant capacity were determined. When analyzing the immediate effect of different treatments, a clear influence of HHP was observed in all the components of the proximal analysis. Regarding color, none of the three chromatic parameters showed significant differences with control leading to a minimum ΔE at 300 MPa/3 min. Changes in bound and free phenolic acids were evidenced after treatments. The maximum levels of TPC as well as antioxidant capacity were observed at 500 MPa/5 min. By the end of storage, all treated samples discolored leading to ΔE = 14.9 at 500 MPa/5 min. The profile of free and bound phenolic acids presented differences compared to Day 0. The antioxidant capacity by means of ORAC increased for treatments above 300 MPa/5 min indicating the effectiveness of these treatments for the production of functional products based on gooseberry pulp. For treatments above 400 MPa/3 min, molds and yeasts were not detected.     

Phytochemical and antioxidant characterization of the fruit of black sapote (Diospyros digyna Jacq.)

Consumption of fruits and vegetables has been associated with a healthy state which has been attributed, in part, to their antioxidant capacity. Characterization of the bioactive compounds with antioxidant activity found in fruits cultivated in the tropic is limited. Thus, the objective of the present work was the characterization of phytochemicals and antioxidants of the fruit of black sapote (Diospyros digyna Jacq.). HPLC-DAD-Mass Spectrometry (HPLC-MS) analyses were used to identify and quantify phenolics, carotenoids and tocopherols. Total soluble phenolic content was 247.8 mg GAE/100 g fw (fresh weight). Important phenolics identified were sinapic acid, myricetin, ferulic acid, and catechin. Total carotenoid content was 399.4 ??g of ??-carotene/100 g fw, and ??-carotene and lutein were the main carotenoids identified. ??-Tocopherol concentration was 672.0 ??g/100 g dry weight. Antioxidant capacity as measured by the DPPH and FRAP assays was higher in the hydrophilic than in the lipophilic extract, and it is thought to be due mainly to the phenolic content of this fruit. Results suggest that the fruit of black sapote has an antioxidant capacity comparable to other important fruits, and its inclusion in the diet is therefore recommended.     

Chemical composition, nutritional value, and antioxidant constituents of Kalopanax pictus leaves

This study was carried out to analyze the nutritional composition, mineral content and antioxidant activity of Kalopanax pictus leaves. K. pictus leaves are high in carbohydrates (60.37%) and crude protein content (27.05%) on a dry weight basis with low content of fatty acids (1.45%). Hyperoside (1), 3,5-di-O-caffeoyl quinic acid (2), methyl 3,5-dicaffeoyl quinate (3), and 3-O-feruloylquinic acid (4) were isolated and purified from this plant as well. In all the chemical assays used, compound 3 exerted better 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity, reducing power ability, and was a potent inhibitor of hydrogen peroxide (H₂O₂)-induced human embryonic kidney 293 (HEK 293) cell death and lipid peroxidation, whereas compound 4 presented as a powerful radical scavenger against superoxide radicals. Our results suggest that the chemical components of K. pictus leaves possess good antioxidant capacities and this species might have potential applications in the food and medical industries.     

Phenolic compounds content and antioxidant activity in pomace from selected red grapes (Vitis vinifera L. and Vitis labrusca L.) widely produced in Brazil

The phenolic compounds content and antioxidant activity of pomace from the vinification of grape varieties widely produced in Brazil (Cabernet Sauvignon, Merlot, Bordeaux and Isabel) were investigated with a view to their exploitation as a potential source of natural antioxidants. Cabernet Sauvignon grape pomace was found to have the highest content of total phenolic compounds (74.75 mg gallic acid equivalent (GAE)/g), the highest antioxidant activity (determined using the 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging methods; 485.42 and 505.52 μMol Trolox equivalent antioxidant capacity (TEAC)/g, respectively), and the highest reducing power (determined using the FRAP method; 249.46 μMol TEAC/g). The Bordeaux variety showed the highest oxidation inhibition power (41.13%), determined using the β-carotene/linoleic acid method and the highest content of total anthocyanins (HPLC; 29.17 mg/g). Catechin was the most abundant non-anthocyanic compound identified in the grape pomace (150.16 mg/100 g) for all varieties. In this study, pomaces of the red wine vinification of Cabernet Sauvignon and Bordeaux varieties showed the highest potential as a source of antioxidant compounds and natural colourants, respectively.     

Variation of total phenolics, anthocyanins, ellagic acid and radical scavenging capacity in various raspberry (Rubus spp.) cultivars

The aim of this study was to assess the level of some phytochemicals in 19 raspberry cultivars grown in Lithuania. The content of total ellagic acid measured after 20 h acidic hydrolysis of investigated raspberry cultivars, varied from 119.8 (cv. ‘Pokusa’) to 323.5 mg/100 g (cv. ‘Bristol’). The content of total phenolics ranged from 278.6 (cv. ‘Pokusa’) to 714.7 mg/100 g (cv. ‘Bristol’). The total anthocyanins content varied from 2.1 (yellow cv. ‘Beglianka’) to 325.5 mg/100 g (black cv. ‘Bristol’). The radical scavenging capacity of the tested raspberry cultivars highly correlating with their total phenolics and total ellagic acid content (r = 0.90 and 0.92, respectively). The results of this study expand the knowledge about variation in the content of valuable bioactive compounds in raspberries and may help for the selection and validation of the most productive cultivars.