Antioxidant capacities of phenolic compounds and tocopherols from Tunisian pomegranate (Punica granatum) fruits

This article aims to determine the phenolic, tocopherol contents, and antioxidant capacities from fruits (juices, peels, and seed oils) of 6 Tunisian pomegranate ecotypes. Total anthocyanins were determined by a differential pH method. Hydrolyzable tannins were determined with potassium iodate. The tocopherol (α-tocopherol, γ-tocopherol, and δ-tocopherol) contents were, respectively, 165.77, 107.38, and 27.29 mg/100 g from dry seed. Four phenolic compounds were identified and quantified in pomegranate peel and pulp using the high-performance liquid chromatography/ultraviolet method: 2 hydroxybenzoic acids (gallic and ellagic acids) and 2 hydroxycinnamic acids (caffeic and p-coumaric acids). Juice, peel, and seed oil antioxidants were confirmed by ferric reducing antioxidant power (FRAP) and oxygen radical absorbance capacity (ORAC) methods. The highest values were recorded in peels with 25.63 mmol trolox equivalent/100 g and 22.08 mmol TE/100 g for FRAP and ORAC assay, respectively. Results showed that the antioxidant potency of pomegranate extracts was correlated with their phenolic compound content. In particular, the highest correlation was reported in peels. High correlations were also found between peel hydroxybenzoic acids and FRAP ORAC antioxidant capacities. Identified tocopherols seem to contribute in major part to the antioxidant activity of seed oil. The results implied that bioactive compounds from the peel might be potential resources for the development of antioxidant function dietary food.     

Analysis of Phenolic Composition of Noble Muscadine (Vitis rotundifolia) by HPLC‐MS and the Relationship to Its Antioxidant Capacity

Abstract: Phenolic compounds and anthocyanins in muscadines have attracted much attention due to their diverse biological activities. With bioassays of antioxidant activities in terms of total phenolic content (TPC), total anthocyanin content (TAC), total procyanidin content (TPA), oxygen radical absorbance capacity (ORAC), and ferric reducing antioxidant power (FRAP) of different parts of the Noble muscadine, the butanol (BuOH) extract of the muscadine skin showed the highest TPC (317.91 ± 1.83 mg GAE/100 g FW), which might be ascribed to its high TAC of 227.06 ± 1.29 mg/100 g fresh weight (FW). The ethyl acetate (EtOAc) extract of the muscadine seed contained the highest TPA (55.30 ± 0.63 mg CE/100 g FW). Correlation analyses demonstrated a significant linear relationship of TPC and TAC compared to their ORAC and FRAP values within the range of R² from 0.9283 to 0.9936, which suggested that phenolics and anthocyanins in the extracts contributed significantly to their antioxidant potential. Nineteen individual phenolics and 5 anthocyanins were identified by HPLC‐MS, which indicated different chemical profiles of anthocyanins and other phenolics in the muscadine extracts. Practical Application: The paper has provided rich information of bioactive phytochemical profiles in different solvent extracts and their correlation with the antioxidant activity in the muscadine that is a very special regional fruit in U.S. Its high content of phenolic compounds demonstrates that muscadine could be beneficial to human health.     

Antiproliferative and antioxidant activities of Turkish pomegranate (Punica granatum L.) accessions

The objective of this study was to assess antioxidant and antiproliferative activities of four different Turkish pomegranate varieties (Hatay, Hicaz, Adana and Antalya) using an in vitro HepG2 cancer cell model. All the pomegranate extracts employed in this study significantly diminish the proliferation of HepG2 cells in a dose‐dependent manner. The total phenolic acid, anthocyanin and flavonoid contents for each of the four varieties were determined. The Hatay pomegranate variety had the highest total phenolic acid (337.4 ± 2.34 mg/100 g) and flavonoid (58.42 ± 2.25 mg/100 g) contents of the pomegranates examined. Antioxidant activities of the pomegranates were determined using DPPH and ABTS radical scavenging assays. The lack of correlation between colour index value and antioxidant–antiproliferative activities suggested that phenolic acids and flavonoids are predominant compounds influencing pomegranate's bioactivity rather than anthocyanins. Individual phenolic acids found in Hatay pomegranates were determined, using an HPLC system, as gallic acid being the most predominant phenolic compound.     

Antioxidant activity and polyphenol content of Turkish thyme (Thymus vulgaris) monitored by liquid chromatography and tandem mass spectrometry

Like tea, the leaves of Turkish thyme (Thymus vulgaris) can be boiled in water to produce an extract. This is widely used as syrup for the treatment of coughs and bronchitis at alternative medicine clinics in many parts of the world. In the current study, we assessed the phenolic content and antioxidant activity of thyme. The antioxidant activities of both ethanol and aqueous extracts of thyme were determined using various in vitro methods. The total phenolic and total flavonoid contents were determined to be a gallic acid equivalent and a quercetin equivalent, respectively. Finally, the quantities of the phenolic compounds were detected using high-performance liquid chromatography and tandem mass spectrometry. The total phenolic compounds in the aqueous extract and ethanol extracts of Turkish thyme were 256.0 μg gallic acid equivalent/mg dried extract and 158.0 μg gallic acid equivalent/mg dried extract, respectively. Conversely, the total flavonoid compounds in both extracts were 44.2 μg and 36.6 μg quercetin equivalent/mg dried extract, respectively. For the first time, we determined phenolic contents and investigated the antioxidant potential of thyme. The results indicate that Turkish thyme is a good dietary source with phenolic properties.     

Aroma,Sugar and Anthocyanin Profile of Fruit and Seed of Mahlab (Prunus mahaleb L.): Optimization of Bioactive Compounds Extraction by Simplex Lattice Mixture Design

In the present study, bioactive properties of black mahlab fruit and seed were investigated. Simplex lattice mixture design was used to determine the best solvent composition for the extraction of bioactive compounds of the samples. The content of total phenolics, total flavonoids, condensed tannins, total anthocyanins, and antiradical efficiency of mahlab fruit and seed extracts were investigated by spectrophotometric methods. Moreover, major sugar composition, individual anthocyanins, fatty acids, and aroma profile of the samples were determined by chromatographic methods. Effect of temperature on degradation of anthocyanins was also investigated, and degradation kinetic model parameters were calculated. Finally, the constructed simplex lattice mixture design model was optimized to estimate the optimum solvent mixtures that would yield maximum total phenolic content. The best solvent mixture was found to be 36 % of acetone and 64 % of water. It was concluded that the experimental and predicted values were in good agreement. Total phenolics and flavonoids of the fruit were 2,266 mg gallic acid equivalent/100 g of dry sample and 946.57 mg catechin equivalent/100 g of dry sample, respectively. Total anthocyanin content of the fruit was 505.7 mg/100 g of dry sample. Temperature showed a significant degradation effect on the anthocyanins.     

蓝莓果渣花色苷提取工艺优化及抗氧化活性比较研究

以蓝莓干果渣为原料,酸化乙醇为溶剂,应用超声辅助法提取花色苷,利用pH示差法测定花色苷含量,通过单因素实验和响应面试验优化得出蓝莓干果渣花色苷提取工艺条件,比较相同干重的蓝莓干果渣、湿果渣采用超声辅助提取和无超声辅助工艺得到的提取液的总多酚、花色苷含量及抗氧化活性。结果表明,蓝莓干果渣最佳提取工艺为液料比(31:1)mL/g,乙醇浓度63%,pH2.6,超声功率500 W,提取时间20 min,在此条件下蓝莓果渣提取液中花色苷含量为498.84 mg/100 g。相同原料,超声辅助提取工艺提取液较无超声辅助提取工艺提取液的总多酚和花色苷含量多;相同工艺条件下,相同干重的湿果渣总多酚和花色苷含量较干果渣低,但却拥有更高的抗氧化活性。     

黑果腺肋花楸花色苷提取工艺优化及其抗氧化活性和组成鉴定

目的：优化超声波辅助提取黑果腺肋花楸花色苷的条件,测定花色苷的抗氧化能力,鉴定黑果腺肋花楸花色苷提取物的组成成分。方法：采用响应面法优化花色苷提取条件,通过1,1-二苯基-2-三硝基苯肼自由基清除能力、2,2’-联氨-双（3-乙基苯并噻唑啉-6-磺酸）二铵盐自由基清除能力及Fe3＋还原能力方法评价其抗氧化能力,高效液相色谱-质谱联用法进行成分分析。结果表明：提取温度60?℃、超声功率100?W、料液比1∶30（g/mL）、超声时间31?min、乙醇体积分数64%和pH?2.0时为最优提取条件,此时黑果腺肋花楸花色苷含量可达（3.61±0.01）mg/g。体外抗氧化实验表明,在相同质量浓度条件下,黑果腺肋花楸花色苷提取物的抗氧化活性明显高于VC。组分鉴定表明黑果腺肋花楸花色苷提取物中共有6?种花色苷,其中矢车菊-己糖苷二聚体和矢车菊-3,5-二己糖苷为新检测出的2?种花色苷。     

Identification of phenolic compounds from pomegranate (Punica granatum L.) seed residues and investigation into their antioxidant capacities by HPLC-ABTS assay

In this study, phenolic compounds were extracted and isolated from pomegranate seed residue (PSR). Phytochemicals and antioxidant capacity of extracts from PSR were firstly investigated. Total phenolic (TP) and proanthocyanidin (PC) contents of the extracts were determined as 2427.90 and 505.63 mg catechin equivalent of 100 g dry weight respectively. To evaluate the antioxidant capacity of individual compounds, on line assay of coupling high performance liquid chromatographic separation with ABTS free radical reaction system (HPLC-ABTS⁺) was carried out. 17 compounds in PSR extracts were detected with antioxidant capacity, and HPLC associated with electrospray ionization mass spectrometry (HPLC-ESI-MS) was used to identify them. The main phenolics in PSR identified were flavol-3-ols, phenolic acids, flavonoid glycosides, and hydrolysable tannin. The results showed that PSR contained some amount of antioxidant compounds, and the HPLC-ABTS⁺ on line method was fast, sensitive and effective.     

Phenolic Profiles,Antioxidant Activities,and Neuroprotective Properties of Mulberry (Morus atropurpurea Roxb.) Fruit Extracts from Different Ripening Stages

The present work investigated the phenolic profiles (including nonanthocyanin and anthocyanin phenolics), antioxidant activities, and neuroprotective potential of mulberry fruit (MF) (Morus atropurpurea Roxb.) grown in China at different ripening stages. High‐performance liquid chromatography‐tandem mass spectrometry method (HPLC‐MS/MS) was used to identify and quantify the phenolic compounds. The antioxidant capacity, total phenolic content (TPC), total flavonoid content (TFC), and total monomeric anthocyanin content (TAC) were determined using spectrophotometric methods. The neuroprotective effects of MFs at different ripening stages were investigated using Aβ_25‐35‐treated PC12 cells as the cellular model of Alzheimer's disease. Of the 19 phenolic compounds characterized from the MF extracts, the contents of rutin and anthocyanins increased and that of chlorogenic acid decreased significantly with maturity. At the fully ripened stage, MF extracts showed the highest amounts of TPC (11.23 mg gallic acid equivalents/g fresh weight), TFC (15.1 mg rutin equivalents/g fresh weight), and TAC (1177 mg cyanidin 3‐O‐glucoside equivalents/100 g fresh weight). Meanwhile, antioxidant activity of MF extracts at this stage was highest according to ABTS (an IC50 value of 4.11 μg/mL) and DPPH (an IC50 value of 10.08 μg/mL) assays. Cellular assays revealed increased cell viability in cells treated with the ripe MF extracts; compared with the control groups, the ripening fruits also increased the antioxidant enzyme levels in PC12 cells. Together, these results suggest that the antioxidant activities and neuroprotective properties of ripening MFs are related to the contents and types of phenolic compounds that are present in the fruits.     

Antioxidant phenolic compounds of pomegranate wines produced by different maceration methods

Various methods were evaluated in the production of ‘Hicaz’ pomegranate wine by microvinification. The chemical, phenolic and antioxidant characteristics of the wines were assessed by measurement of water‐soluble dry matter, acidity, density, alcohol content, volatile acidity, total monomeric anthocyanins, polarized colour intensity and individual phenolic compounds. Three different methods – classical maceration (N), seed‐supplemented maceration (S) and seed + enzyme supplemented maceration (E) – were applied. Total phenolic compounds of pomegranate must and wines (after 18 months of storage) were 1897 mg/L (must), 1663 mg/L (N), 1339 mg/L (E) and 1414 mg/L (S). Phenolic compounds in pomegranate must and wines included gallic acid, vanillic acid, caffeic acid, ferulic acid, p‐coumaric acid, hydroxycinnamic acid, epicatechin and catechin. Total antioxidant capacities (Trolox equivalents) of pomegranate must and wines (N, E and S) were 9.9 mm /L (must), 9.8 mm /L (N), 9.7 mm /L (E) and 9.5 mm /L (S). Copyright © 2017 The Institute of Brewing & Distilling     

Phenolic compounds and antioxidant activity of seed and skin extracts of red grape (Vitis vinifera and Vitis labrusca) pomace from Brazilian winemaking

The phenolic compounds content and antioxidant activity of seed and skin of pomace from the vinification of grape varieties widely produced in Brazil were investigated with a view to their exploitation as a potential source of natural antioxidants. There was a greater concentration of phenolic compounds in the seeds (2128 to 16,518 mg of catechin equivalents (CE)/100 g) than in the skins (660 to 1839 mg CE/100 g). The highest antioxidant activity values determined as DPPH radical-scavenging ability and ferric reducing-antioxidant power (FRAP) were found for the seeds of the Pinot Noir variety (16,925 ??mol Trolox equivalents (TE)/100 g and 21,492 ??mol Fe²⁺/100 g, respectively) and in the skin extracts of the Isabel variety (3640 ??mol TE/100 g and 4362 ??mol Fe²⁺/100 g, respectively). The skin of Cabernet Sauvignon and Primitivo varieties had the highest contents of anthocyanins (935 and 832 mg/100 g, respectively). The grape seed extracts were rich in oligomeric and polymeric flavanols. The data suggested that grape seed and skin extracts may be exploited as antioxidant agents.     

超高压提取蓝莓渣花色苷的工艺优化及其抗氧化活性

本文旨在优化蓝莓渣花色苷的超高压提取工艺并考察其抗氧化活力。本文以蓝莓渣为原料,采用单因素实验和Box-Behnken响应面分析法对蓝莓渣花色苷的提取工艺进行优化,以维生素C（V_C）为阳性对照,通过DPPH自由基清除率、羟基自由基清除率和FRAP铁离子还原能力的测定,评估蓝莓渣花色苷的体外抗氧化活性,并采用高效液相色谱法（HPLC）对蓝莓渣花色苷组分进行分析。结果表明:蓝莓渣花色苷的最佳提取工艺条件为:提取压力400 MPa,提取时间9 min,乙醇浓度60%,料液比1:20 g/mL,此条件下花色苷的提取量为5.93±0.06 mg/g,与传统溶剂浸提法（CSE）、超声波辅助提取法（USE）相比,超高压辅助提取（UPE）法的提取效果更好,花色苷提取量分别提高25.11%、10.02%;蓝莓渣花色苷对DPPH?清除能力最强,与同浓度的V_C相比,无显著性差异（P>0.05）;其对?OH的清除率以及FRAP铁离子还原能力则显著弱于同浓度V_C（P<0.05）;HPLC分析结果表明,蓝莓渣花色苷包含13种花色苷单体,其中锦葵色素-3-半乳糖苷含量最高。因此,超高压辅助提取是一种高效的蓝莓渣花色苷提取方法,且蓝莓渣花色苷因其较强的抗氧化活性具有较好的应用价值。     

Antioxidant activity, phenolic compounds and anthocyanins content of eighteen strains of Mexican maize

Free-radical scavenging, reducing activity and some phytochemical content (total phenolic, anthocyanin and ferulic acid) of eighteen Mexican maize phenotypes were determined. Total phenolic contents ranged from 215.8 to 3400.1 mg gallic acid/100 g of whole grain flour and total anthocyanins ranged from 1.54 to 850.9 mg cyanidin-glucoside equivalents/100 g of whole grain flour. Most of the phenolics in grain were in the bound form (ca. 85%), while anthocyanins were the major free phenolic compounds. Among the different samples, bound phenolic extracts of corn appeared to have greater anti-radical and reducing activities than free phenolic extracts from the same grain samples when tested at a normalized phenolic concentration. The phenotypes Veracruz 42 and AREQ516540TL exhibited the greatest activities and these purple-colored strains were most enriched in anthocyanins. Extracts from a red-colored phenotype Pinto were also among the most effective at exhibiting anti-radical activities. Differences in free-radical scavenging and reducing activities appeared to be dependent on the unique profile of anthocyanins and other phenolics in each phenotype.     

Effects of different solvents on total phenolic and total anthocyanin contents of Clitoria ternatea L. petal and their anti-cholesterol oxidation capabilities

Clitoria ternatea (CT) petals have a high content of polyphenolic compounds, including anthocyanins, which protect against lipid oxidation. This research evaluated total phenolic content, total anthocyanin content and antioxidant activity of CT extracts obtained using distilled water, methanol, and/or water-methanol combination (1:1) solvents after 6, 12 and 24 h soaking times. The predominant bioactive compounds of CT petals were kaempferol 3-neohesperidoside (462.63 mg per 100 g), caffeoylmalic acid (137.59 mg per 100 g), and kaempferol 3-(2G-rhamnosylrutinoside) (129.28 mg per 100 g). The capacity of each solvent-type extract obtained from 6 h soaking time to inhibit cholesterol oxidation was determined after 24 and 48 h in an emulsion model. At 6 h soaking time, the combination-solvent yielded an extract with the highest anthocyanin content (63.9 μg mL⁻¹) and inhibited 89.8% of 7-ketocholesterol production in emulsion, compared to the control. This study demonstrated that CT petal extracts can enhance health benefits and lengthen shelf life of emulsion-type products.     

Effect of Extraction Techniques and Solvents on Antioxidant Activity of Pomegranate (<Emphasis Type="Italic">Punica granatum</Emphasis> L.) Leaf and Stem

The effect of commonly used techniques and solvents in the antioxidant activities of Pomegranate leaves and stems were studied. The extraction techniques compared were successive, individual (cold percolation), and decoction methods in both parts using solvents viz. petroleum ether, toluene, ethyl acetate, acetone, and water. The antioxidant activity of all the different solvent extracts of leaves and stem was evaluated using antioxidant assays like 2,2-diphenyl-1-picryl hydrazyl free radical scavenging assay, superoxide anion radical scavenging assay and ferric-reducing antioxidant power. Total phenol and flavonoid content was also measured. Successive extraction was a better technique to extract the antioxidants from pomegranate than other techniques evaluated in the present study. For the aqueous extraction, decoction method was found to be the best method to extract the antioxidants and it is the most convenient, exhaustive, and time-saving extraction technique for both parts of pomegranate. The results showed that the extracting solvent significantly altered the antioxidant property estimations of pomegranate leaf and stem. High correlations between phenolic compositions and antioxidant activities of pomegranate extracts were observed. High levels of antioxidant activities were detected in pomegranate leaf as compared to stem indicating that the leaf may serve as an excellent source of natural antioxidants.     

Jam Processing Effect on Phenolics and Antioxidant Capacity in Anthocyanin-rich Fruits: Cherry, Plum, and Raspberry

ABSTRACT: Four cultivars of sour cherries (Balaton, Karneol, Kroeker and Northstar), 2 cultivars of plums (BY 8158.50 and Methley), and 1 red raspberry cv. Prelude were analyzed for total phenolics, antioxidant capacity, and total anthocyanins before and after jam production to evaluate their changes after thermal processing. Fruits had total phenolics ranging from 245.7 to 398.5 mg gallic acid equivalent (GAE)/100 g. Antioxidant capacity of fruits ranged from 354.8 to 692.3 mg/100 g, expressed as vitamin C equivalent antioxidant capacity (VCEAC). Total anthocyanins of fruits ranged from 30.9 to 67.1 mg cyanidin 3-glucoside equivalent (CGE)/100 g. In 100 g of jam, total phenolics varied from 132.9 to 218.9 mg GAE, while antioxidant capacity ranged from 205.6 to 373.5 mg/100 g VCEAC. Jams had total anthocyanins of 5.4 to 30.4 mg CGE/100 g. On the basis of fresh fruit (100 g), the processing and heating during jam making generally decreased the contents of total phenolics, VCEAC, and total anthocyanins. Major losses occurred in anthocyanin content where overall retention varied from 89% to 21%. HPLC analysis of individual anthocyanins from cherry cv. Balaton to its jam showed that processing caused 90% decrease in anthocyanins. The results indicated that more than 73% total phenolics and more than 65% antioxidant capacity were retained after processing fruits into jams. Optimization of food processing would help to conserve the bioactive phenolic compounds in fruits.     

蔓越莓花色苷的组成鉴定及抗氧化能力

对蔓越莓花色苷的组成进行鉴定,并对其抗氧化能力进行测定。采用pH示差法测定花色苷提取量,超高压辅助提取蔓越莓花色苷含量为（75.49±0.43）mg/100?g,常规溶剂提取蔓越莓花色苷含量为（67.31±1.08）mg/100?g,蔓越莓中总花色苷含量为（79.52±0.50）mg/100?g;选择AB-8大孔树脂对蔓越莓花色苷粗提物进行纯化,冻干粉中花色苷含量从（46.10±0.92）mg/g提高到（309.26±2.37）mg/g。通过测定1,1-二苯基-2-三硝基苯肼自由基清除率、2,2’-联氮基-双-（3-乙基苯并噻唑啉-6-磺酸）二铵盐自由基清除能力和总抗氧化能力,比较蔓越莓花色苷与VC的抗氧化能力。结果表明：同质量浓度条件下,蔓越莓花色苷的抗氧化能力强于VC。通过高效液相色谱-质谱联用技术在蔓越莓中鉴定出7?种花色苷：芍药素-3,5-二己糖苷、矢车菊素-3-半乳糖苷、矢车菊素-3-葡萄糖苷、矢车菊素-3-阿拉伯糖苷、芍药素-3-半乳糖苷、芍药素-3-葡萄糖苷、芍药素-3-阿拉伯糖苷,其中芍药素-3,5-二己糖苷首次在蔓越莓中被鉴定出。     

红薯叶不同溶剂提取物抗氧化性及活性成分鉴定

研究不同极性溶剂对红薯叶中酚类化合物的提取以及提取物抗氧化性的影响,并鉴定提取物中的主要抗氧化成分组成。分别采用极性不同的7 种溶剂（蒸馏水、甲醇、无水乙醇、丙酮、正丁醇、乙酸乙酯和氯仿）从红薯叶中提取多酚,并评价提取物中总酚、总黄酮和花青素的含量,以及对1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）自由基清除能力和还原能力,最后运用高效液相色谱-串联质谱（high performance liquidchromatography tandem mass spectroscopy,HPLC-MS/MS）技术分析抗氧化活性最好的提取物中多酚的主要组成成分。结果表明：提取溶剂的极性对红薯叶中多酚类化合物的提取效率和提取物抗氧化活性有很大的影响,水提物具有最高的粗提物得率（（37.13±1.60）%）,而甲醇提取物中总酚含量（13.80 mg GAE/g）和总黄酮含量（（5.68±0.35）mg QE/g）最高,且具有最好的DPPH自由基清除能力（IC50为0.32 mg/mL）与还原能力（ρ0.5为0.95 mg/mL）。采用HPLC-MS/MS从红薯叶甲醇提取物中鉴定9 种、初步鉴定3 种酚类化合物,鉴定的化合物为咖啡酸、对羟基苯甲酸、1-咖啡酸奎宁酸、3-咖啡酸奎宁酸、异绿原酸A、异绿原酸B、异绿原酸C、3,4,5-三咖啡酰奎尼酸和金丝桃苷。     

Determination of Anthocyanins, Total Phenolic Content, and Antioxidant Activity in Andes Berry (Rubus glaucus Benth)

ABSTRACT:  Anthocyanins, total phenolic content, ascorbic acid content, and the antioxidant activity were determined in extracts of Andes berry fruit ( Rubus glaucus Benth). Anthocyanis (ACNs) were isolated and characterized by means of high-performance liquid chromatography (HPLC) with photodiode array detection and electro spray ionization/mass spectrometry (PDA-ESI/MS/MS) analysis. The anthocyanin (ACN) content was 45 mg/100 g FW. The isolated anthocyanins were characterized as cyanidin 3-sambubioside, cyanidin 3-glucoside, cyanidin 3-xylorutinoside, cyanidin 3-rutinoside, pelargonidin 3-glucoside, and pelargonidin 3-rutinoside. The ascorbic acid content was 10.1 mg/100 g FW. The total phenolic content as determined by the Folin–Ciocalteau method was 294 mg GAE/100 g FW while the antioxidant activity as measured by ABTS ^{· +} radical scavenging capacity and ferric reducing antioxidant power (FRAP) was 2.01 and 4.50 mmol TE/100 g FW or 8.22 mmoles ferric iron reduced/100 g FW, respectively. The high phenolic content and antioxidant capacity of Andes berry suggest that this fruit could be a rich source of natural pigments, nutraceuticals, and natural antioxidants.     

紫马铃薯花色苷的提取纯化与鉴定

对超声波辅助提取紫马铃薯花色苷工艺条件进行优化,并用NKA-9大孔吸附树脂进行纯化,液相色谱结合紫外-可见光谱扫描分离和鉴定花色苷组成。结果表明：花色苷最佳提取条件为料液比1:50(2.5g/100mL柠檬酸溶液)、超声功率400W、提取温度45℃、提取时间10min,以干质量计算紫马铃薯种花色苷含量为1.362mg/g;用NKA-9大孔吸附树脂纯化,8倍柱床体积洗脱出占总量98.35%的的花色苷,花色苷纯度达到90.23%;高效液相色谱鉴定出紫马铃薯含有5种组分,其中3种分别是矢车菊素-3-葡萄糖苷、矢车菊素-3-芸香糖苷和芍药-3-葡萄糖苷,其含量分别为0.27、0.057mg/g和0.46mg/g,三者总和占马铃薯中总花色苷含量的57.78%。马铃薯中含量最高的花色苷成分出峰保留时间为12.224min,其结构未知。