Effect of allyl isothiocyanate on antioxidant enzyme activities,flavonoids and post-harvest fruit quality of blueberries (Vaccinium corymbosum L., cv. Duke)

The effect of allyl isothiocyanate (AITC) on antioxidant enzyme activities, flavonoid content, and fruit quality of blueberries var. Duke (Vaccinium corymbosum L.) was evaluated. Results from this study showed that AITC was effective in maintaining higher amounts of sugars and lower organic acids compared to untreated fruit during storage at 10 °C. However, AITC reduced antioxidant enzyme activities [superoxide dismutase (SOD), guaiacol peroxidase (G-POD), glutathione-peroxidase (GSH-POD), ascorbate peroxidase (AsA-POD), dehydroascorbate reductase (DHAR), monodehydroascorbate reductase (MDAR) and glutathione reductase (GR)] and non-enzyme components, ascorbate (AsA) and glutathione (GSH). AITC treatments also reduced the amount of phenolic acids (chlorogenic acid, myricetin 3-arabinoside, quercetin 3-galactoside, quercetin 3-arabinoside, and kaempferol 3-glucoside) and anthocyanins (delphinidin 3-galactoside, delphinidon 3-glucoside, delphinidin 3-arabinoside, petunidin 3-galactoside, petunidin 3-glucoside, petunidin 3-arabinoside, malvidin 3-galactoside, and malvidin 3-arabinoside) during storage at 10 °C. The results from this study indicate that AITC does not promote antioxidant property or scavenge constitutive reactive oxygen species (ROS), but maintain blueberry fruit quality through other mechanisms.     

云南丽江和吉林靖宇11种越橘果实花色苷组分的分析

采用高效液相色谱法对云南丽江、吉林靖宇11种越橘果实花色苷组分进行测定。通过标准品的分析,建立了飞燕草素-3-半乳糖苷、飞燕草素-3-葡萄糖苷、矢车菊素-3-半乳糖苷、矢车菊素-3-葡萄糖苷、锦葵色素-3-半乳糖苷、锦葵色素-3-葡萄糖苷的回归方程,相关系数为0.9939~0.9968,精密度RSD为2.00%~3.73%,回收率在98.90%~100.99%,方法准确可行。通过6种标准品的对比,供试的15个样品中,所有越橘品种均有飞燕草素-3-半乳糖苷、矢车菊素-3-半乳糖苷、锦葵色素-3-半乳糖苷3种花色苷,飞燕草素-3-半乳糖苷平均含量为223.99 μg/g、锦葵色素-3-半乳糖苷平均含量为153.34 μg/g,二者占总花色苷的65%。采用欧氏距离聚类分析表明,集群1为飞燕草素-3-半乳糖苷含量较高的三种越橘,代表品种为丽江雷戈西、丽江奥尼尔、靖宇杜克;集群2为6种花色苷总含量较高的越橘品种,代表品种为丽江北陆与靖宇早蓝,说明飞燕草素-3-半乳糖苷含量与花色苷总含量是评价越橘花色苷特点的重要因子。     

Characterisation and preliminary bioactivity determination of Berberis boliviana Lechler fruit anthocyanins

Berberis boliviana Lechler is a member of the Berberidaceae family that has a small edible red-purple berry. The plant is native to the Peruvian Andes and contains high amounts of anthocyanin pigments. The monomeric anthocyanin content, determined by a pH-differential method, was 7/100 g of seedless berries. Pigments were characterised by HPLC coupled to a photodiode array (PDA) and mass spectrophotometer (MS) detectors. Five aglycones and ten anthocyanins were found and identified as petunidin-3-glucoside (24.4%), delphinidin-3-glucoside (24.1%), malvidin-3-glucoside (22.1%), cyanidin-3-glucoside (10.2%), petunidin-3-rutinoside (7.15%), malvidin-3-rutinoside (4.9%), cyanidin-3-rutinoside (3.8%), delphinidin-3-rutinoside (2.6%), peonidin-3-glucoside (1.1%), and peonidin-3-rutinoside (0.9%).     

Copigmentation between malvidin-3-glucoside and some wine constituents and its importance to colour expression in red wine

Thermodynamic parameters for intermolecular copigmentation interactions involving malvidin-3-glucoside were determined by UV/visible spectroscopy at wine pH (pH 3.6). These included association constants, enthalpy and entropy changes, which were measured for chlorogenic acid, caffeic acid, quercetin, quercetin-3-glucoside, (−)-epicatechin, (+)-catechin, procyanidin dimer and seed tannin. Quercetin produced the strongest copigment (K_CP = 2900 ± 1300), whilst the addition of glucose at position 3 (quercetin-3-glucoside) reduced its effect by almost 10-fold. Malvidin-3-glucoside self-association (K_D = 3300 ± 300 mol⁻¹ l) was thermodynamically favoured over intermolecular interaction with any of the copigments tested. No colour enhancement due to self-association was observed for malvidin-3-glucoside-derived pigments that cannot enter hydration reactions. In addition, malvidin-3-(6-O-p-coumaryl)glucoside did not show colour enhancement suggesting that the p-coumaryl group prevents self-association. The malvidin-3-glucoside circular dichroism (CD) spectrum was not affected by indicated changes in malvidin-3-glucoside concentration. These observations demonstrate that self-association of malvidin-3-glucoside is more important than copigmentation in young red wine.     

Identification and characterisation of anthocyanins in the antioxidant activity-containing fraction of Liriope platyphylla fruits

The objective of this study was to investigate antioxidant activities and anthocyanin profiles in the fruits of Liriope platyphylla, where these are considered functional substances in Korea. The acidic methanol extract of this species exhibited potent antioxidant activities, showing 83.9% DPPH scavenging activity and 92.5% ABTS scavenging activity at a concentration of 0.5 mg/ml. Moreover, anthocyanins were identified by reversed-phase C₁₈ column chromatography, NMR spectroscopy, and HPLC-DAD-ESI/MS analysis. Seven anthocyanins were characterised, including delphinidin-3-O-glucoside (1), delphinidin-3-O-rutinoside (2), cyanidin-3-O-glucoside (3), petunidin-3-O-glucoside (4), petunidin-3-O-rutinoside (5), malvidin-3-O-glucoside (6), and malvidin-3-O-rutinoside (7). Among these, petunidin-3-O-rutinoside (5) (7302.2 μg/g) and malvidin-3-O-rutinoside (7) (5776.1 μg/g) were the predominant anthocyanins, whereas the least prevalent anthocyanin was found to be cyanidin-3-O-glucoside (3) (64.9 μg/g). Therefore, our results suggest that strong antioxidant activities of the acidic methanol extract of L. platyphylla fruits are correlated with high anthocyanin contents, particularly the petunidin-3-O-rutinoside (5) and malvidin-3-O-rutinoside (7).     

Postharvest stilbenes and flavonoids enrichment of table grape cv Redglobe (Vitis vinifera L.) as affected by interactive UV-C exposure and storage conditions

Flavonoids and stilbenes are secondary metabolites produced in plants that can play an important health-promoting role. The biosynthesis of these compounds generally increases as a response to biotic or abiotic stress; therefore, in order to achieve as high phenolic accumulation as possible, the interactive effects of storage conditions (temperature and time) and UV-C radiation on polyphenols content in postharvest Redglobe table grape variety were investigated. During a storage time longer than 48 h, both cold storage (4 °C) and UV-C exposure of almost 3 min (2.4 kJ m⁻²) positively enhanced the content of cis- and trans-piceid (34 and 90 μg g⁻¹ of skin, respectively) together with quercetin-3-O-galactoside and quercetin-3-O-glucoside (15 and 140 μg g⁻¹ of skin, respectively) up to three fold respect to control grape samples. Conversely, catechin was not significantly affected by irradiation and storage treatments. With regard anthocyanins, the highest concentrations of cyanidin-3-O-glucoside and peonidin-3-Oglucoside were observed in Redglobe, stored at both room temperature and 4 °C, after 5 min (4.1 kJ m⁻²) of UV-C treatment and 24 h of storage. Gathered findings showed that combined postharvest treatments can lead to possible “functional” grapes, within normal conditions of market commercialization, responding to the rising consumers demand to have foods that support and promote health.     

Chromatographic Separation of Anthocyanins in Cowberry (Lingonberry) Vaccinium vites-idaea L

The analysis of anthocyanins by a combination of droplet counter-current chromatography, thin-layer chromatography and on-line high-performance liquid chromatography was applied to the acidified ethanol extract of cowberry (lingonberry), Vaccinium vitesidaea L, In addition to 3-galactoside (88.0%), 3-arabinoside (10.6%), and 3-glucoside (1.4%) of cyanidin, delphinidin-3-glucoside (less than 0.1%) was identified. The total anthocyanin content was determined to be 174 mg/100g fresh fruit.     

Anthocyanins in cowpea [Vigna unguiculata (L.) Walp. ssp. unguiculata]

The aim of this study was to isolate and identify the anthocyanins in the black seed coated cowpea [Vigna unguiculata (L.) Walp. ssp. unguiculata] using reverse phase C-18 open column chromatography and high performance liquid chromatography (HPLC) with diode array detection and electro spray ionization/mass spectrometry (DAD-ESI/MS) analysis, respectively. Anthocyanins were extracted from the coat of black cowpea with 1% trifluoroacetic acid (TFA) in methanol, isolated by RP-C-18 column chromatography, and their structures elucidated by 1D and 2D nuclear magnetic resonance (NMR) spectroscopy. The isolated anthocyanins were characterized as delphinidin-3-O-glucoside (2) and cyanidin-3-O-glucoside (4). Furthermore, 5 minor anthocyanins were detected and identified as delphinidin-3-O-galactoside (1), cyanidin-3-O-galactoside (3), petunidin-3-O-glucoside (5), peonidin-3-O-glucoside (7), and malvidin-3-O-glucoside (8) based on the fragmentation patterns of HPLC-DADESI/MS analysis.     

Kinetics of Thermal Degradation of the Anthocyanins Delphinidin-3-rutinoside and Malvidin-3-glucoside

The kinetics of the thermal degradation of the two anthocyanins delphinidin-3-rutinoside and malvidin-3-glucoside at 78, 88, 98 and 108 °C, depending on the pH and the type of solvent has been investigated. The first order reaction of delphinidin-3-rutinoside and malvidin-3-glucoside degradation has been established. The rate constants (K ± 10^?5s^?1), the activation parameters, factor Q₁₀ and the half-decay period have been calculated. The rate of delphinidin-3-rutinoside degradation is higher than that of malvidin-3-glucoside.     

Characterisation of anthocyanins in the black soybean (Glycine max L.) by HPLC-DAD-ESI/MS analysis

The aim of this study was to isolate and identify the anthocyanins in the black seed coated soybean (cv. Cheongja 3, Glycine max (L.) Merr.) using reverse phase C-18 open column chromatography and high-performance liquid chromatography (HPLC) with diode array detection and electro spray ionization/mass spectrometry (DAD-ESI/MS) analysis, respectively. Anthocyanins were extracted from the coat of black soybeans with 1% TFA in methanol, isolated by RP-C-18 column chromatography, and their structures elucidated by 1D and 2D NMR spectroscopy. The isolated anthocyanins were characterised as delphinidin-3-O-glucoside (3), cyanidin-3-O-glucoside (5), petunidin-3-O-glucoside (6), pelargonidin-3-O-glucoside (7) and cyanidin (9). Furthermore, four minor anthocyanins were detected and identified as catechin-cyanidin-3-O-glucoside (1), delphinidin-3-O-galactoside (2), cyanidin-3-O-galactoside (4), and peonidin-3-O-glucoside (8) based on the fragmentation patterns of HPLC-DAD-ESI/MS analysis.     

Polyphenols content and antioxidant capacity of eggplant pulp

The influence of organic and conventional farming practices on the phenolic content in eggplant samples belonging to two cultivars, Blackbell (American eggplant) and Millionaire (Japanese eggplant) grown under similar environmental conditions was evaluated. Phytochemical investigation of the eggplant extracts showed that N-caffeoylputrescine, 5-caffeoylquinic acid, and 3-acetyl-5-caffeoylquinic acid made up the bulk of total eggplant phenolics. In addition, this is the first report on identification of trace quantities of three additional flavonols, namely, quercetin-3-glucoside, quercetin-3-rhamnoside, and myricetin-3-galactoside in freeze-dried eggplant pulp. The phenolic content of the conventionally grown Blackbell variety was marginally higher or equal to those grown organically. However, the phenolic content of the Millionaire organic variety was much greater than the conventionally grown samples. Eggplant extract inhibition of cupric-ion mediated oxidation of low-density lipoproteins was highly correlated with the content of 5-caffeolquinic acid (R² = 0.9124), the most abundant phenolic acid identified.     

Polyphenolic compounds characterization and reactive nitrogen species scavenging capacity of Oenothera paradoxa defatted seed extracts

Biological investigations have revealed high scavenging capacity of Oenothera paradoxa defatted seed extract on reactive nitrogen species such as NO and ONOO⁻. The characteristics of the polyphenols present in the extracts were checked using high performance liquid chromatography coupled with electrospray negative ionization ion trap mass spectrometry. Extracts contained five groups of compound: phenolic acids (gallic acid, ethyl gallate, ellagic acid and ferulic acid pentoside), flavanols (catechin, catechin gallate) and oligomeric procyanidins, flavonols (quercetin-3-O-glucoside, quercetin-3-O-glucuronide, quercetin-3-O-pentoside and quercetin), and gallotannins (tetragalloyl glucose, pentagalloyl glucose and hexagalloyl glucose). Penta-O-galloyl-β-d-glucose were present in the extracts in concentrations from 9.44 to 16.75 mg/g, which demonstrated a significant NO and ONOO⁻ scavenging activity with IC₅₀ 0.20 and 0.06 μM, respectively, may be considered as an O. paradoxa extract quality marker.     

Determination of anthocyanins,flavonoids and phenolic acids in potatoes. I: Coloured cultivars of Solanum tuberosum L

The major anthocyanins, flavonoids and phenolic acids in the tubers (skin and flesh), flowers and leaves of 26 cultivars of Solanum tuberosum L with coloured skins and/or flesh have been identified and quantified using analytical HPLC. Red tubers contained mostly pelagonidin-3-(p-coumaroyl-rutinoside)-5-glucoside (200–2000 μg g⁻¹ FW) plus lesser amounts of peonidin-3-(p-coumaroyl-rutinoside)-5-glucoside (20–400 μg g⁻¹ FW). Light to medium purple tubers contained petunidin-3-(p-coumaroyl-rutinoside)-5-glucoside (1000–2000 μg g⁻¹ FW) plus small amounts of malvidin-3-(p-coumaroyl-rutinoside)-5-glucoside (20–200 μg g⁻¹ FW) whilst dark purple–black tubers contained similar levels of petunidin-3-(p-coumaroyl-rutinoside)-5-glucoside together with much higher concentrations of malvidin-3-(p-coumaroyl-rutinoside)-5-glucoside (2000–5000 μg g⁻¹ FW). Tuber flesh also contained chlorogenic acid (30–900 μg g⁻¹ FW) and other phenolic acids plus low concentrations of flavonoids (0–30 μg g⁻¹ FW). Tuber skins showed much higher levels (1000–4000 μg g⁻¹ FW) of chlorogenic acid. The major anthocyanins in flowers were present as the rutinosides or other glycosides of pelargonidin, petunidin and malvidin whilst glycosides of cyanidin and delphinidin were found in some flowers, together with many of the same phenolic acids as found in tubers. The commonest flavonoids included rutin, kaempferol-3-rutinoside and two quercetin-rhamnose-glucosides. Flowers and leaves contained higher concentrations of flavonoids which fell into two patterns, with some cultivars containing high concentrations of quercetin-3-glycosides, whilst others had much lower concentrations. © 1998 SCI.     

Purification and characterization of olive (Olea europaea L.) peroxidase – Evidence for the occurrence of a pectin binding peroxidase

Peroxidase from olive fruit (Olea europaea L., cv Douro) in a black ripening stage was purified to electrophoretic homogeneity, resulting in four cationic and four anionic fractions. The anionic fractions accounted for 92% of recovered activity and showed molecular masses of 18–20 kDa. The anionic fraction PODa4, the predominant fraction that comprised about 70% of total recovered activity, showed an isoelectric point of 4.4 and optimum pH and temperature of, respectively, 7.0 and 34.7 °C, and apparent K_m values of 41.0 and 0.53 mM, for phenol and H₂O₂, respectively. From the activity-temperature profile, the denaturation temperature and the changes in enthalpy and heat capacity for unfolding of PODa4 were estimated as being, respectively, 36.5 °C, 411.2 and −13.6 kJ mol⁻¹ K⁻¹. The activation energy for phenol oxidation by PODa4 was 99.1 kJ mol⁻¹, corresponding to a calculated temperature coefficient (Q₁₀) of 4. The arabinose (39 mol%) and galacturonic acid (38 mol%) content of the carbohydrate moiety indicated the existence of pectic material in the purified PODa4 fraction. Co-migration of the carbohydrate with the protein band in the isoelectric focusing electrophoresis, points to PODa4 fraction as being a pectin type binding peroxidase.     

Anthocyanin composition in aged Chilean Cabernet Sauvignon red wines

Anthocyanins in aged Cabernet Sauvignon red wines were studied by HPLC–MS. The major anthocyanin in 6, 7, and 8 year old red wine extracts was the dimer vitisin A produced by condensation of malvidin-3-O-glucoside mediated by pyruvic acid. In aged wine, the content of malvidin-3-O-glucoside decreased with age with a concomitant increase of vitisin A. The latter is accompanied by several condensation products with molecular weight up to 1500 m/z. Differential pulse voltammetry indicated that aged wines have lower antioxidant capacity than young wine (400 mV), but higher than malvidin-3-O-glucoside (483 mV). Tafel’s plots showed that the electrochemical process occurring in aged wines is different from young wines. Six, seven and eight year old wines show similar behaviour with plots of 234, 177 and 188 mV/dec, respectively. These values are higher than the expected 120 mV/dec corresponding to a first electronic transfer but smaller compared to the 523 mV/dec corresponding to young wine.     

European elderberry (Sambucus nigra L.) rich in sugars,organic acids,anthocyanins and selected polyphenols

Sugars and organic acids in the fruit of two cultivars and three selections of black elderberry (Sambucus nigra L.): ‘Haschberg’, ‘Rubini’, ‘Selection 13’, ‘Selection 14’ and ‘Selection 25’ were quantified. The anthocyanin as well as quercetin profiles of this plant material were also established by the use of HPLC/MS. Significant differences in the concentration of sugars and organic acids were detected between the widely spread cultivar ‘Haschberg’ and all other cultivars/selections; ‘Haschberg’ was the richest in organic acids (6.38 g kg⁻¹ FW), and it contained the least sugar (68.5 g kg⁻¹ FW). The following major cyanidin based anthocyanins were identified in the fruit of black elderberry: cyanidin 3-sambubioside-5-glucoside, cyanidin 3,5-diglucoside, cyanidin 3-sambubioside, cyanidin 3-glucoside and cyanidin 3-rutinoside. The most abundant anthocyanin in elderberry fruit was cyanidin 3-sambubioside, which accounted for more than half of all anthocyanins identified in the berries. The ‘Rubini’ cultivar had the highest amount of the anthocyanins identified (1265 mg/100 g FW) and the lowest amount was measured in berries of the ‘Selection 14’ (603 mg/100 g FW). The ‘Haschberg’ cultivar contained a relatively low amount of anthocyanins in ripe berries (737 mg/100 g FW). From the quercetin group, quercetin, quercetin 3-rutinoside and quercetin 3-glucoside were identified; the latter prevailing in black elderberry fruit. The cultivar with the highest amount of total quercetins was ‘Selection 25’ (73.4 mg/100 g FW), while the ‘Haschberg’ cultivar contained average amounts of quercetins (61.3 mg/100 g FW). The chemical composition of the ‘Haschberg’ cultivar, the most commonly planted, conforms to the standards for sugars, anthocyanins and quercetins and exceeds them in the content levels of organic acids, the most important parameter in fruit processing.     

Drying and quality characteristics of fresh and sugar-infused blueberries dried with infrared radiation heating

We evaluated the finished product quality and infrared (IR) drying characteristics of fresh and sugar-infused blueberries dried with a catalytic infrared (CIR) dryer. IR drying tests were conducted at four product temperatures (60, 70, 80, and 90 °C) to evaluate the drying rate and the color and texture of the finished product. Fresh blueberries dried with convective hot air drying at 60 °C were used as control for comparison. The experimental data of moisture changes during IR drying were modeled with eight different models, including Page, modified Page, Thompson, Newton, Wang and Singh, and Henderson and Pabis, and two models developed in this study. The Thompson model showed the best fit to all experimental data. The CIR drying produced firmer-texture products with much reduced drying time compared with hot air drying. For fresh blueberries, CIR drying conserved drying time by 44% at 60 °C. The effective moisture diffusivity ranged from 2.24 × 10⁻¹⁰ to 16.4 × 10⁻¹⁰ m²/s and from 0.61 × 10⁻¹⁰ to 3.84 × 10⁻¹⁰ m²/s for fresh and sugar-infused blueberries, respectively.     

Characterization of phenolic compounds in Chinese hawthorn (Crataegus pinnatifida Bge. var. major) fruit by high performance liquid chromatography–electrospray ionization mass spectrometry

Hawthorn (Crataegus spp.) fruits are increasingly popular as raw materials for nutraceuticals and functional foods. As a major group of bio-active components of hawthorn, the phenolic compounds of the fruits have not been well characterized so far. After extraction with 80% aqueous ethanol, the phenolics of the fruits of a major Chinese hawthorn variety, Crataegus pinnatifida Bge. var. major, were separated by polyamide column chromatography, followed by analyses by high performance liquid chromatography combined with diode array UV spectrometry and electrospray ionization mass spectrometry. Ideain (cyanidin-3-O-galactoside), chlorogenic acid, procyanidin B2 [epicatechin-(4β → 8)-epicatechin], epicatechin, hyperoside (quercetin-3-O-galactoside) and isoquercitrin (quercetin-3-O-glucoside) were identified with UV spectra, mass spectra and reference compounds. In addition, 35 compounds were tentatively identified based on UV and mass spectra. These compounds were mostly B-type procyanidins (PA) and their glycosides including aglycons of 3 dimers, 3 trimers, 8 tetramers, 4 pentamers, 2 hexamers and 2 glycosides of PA monomers, 7 glycosides of PA dimers, 1 glycoside of a PA trimer, 2 glycosides of PA tetramers, 1 glycoside of a PA pentamer, and 2 glycosides of quercetin. This is the first systematic study of phenolic compounds in Chinese hawthorn fruits and the first report of the presence of glycosylated procyanidins in hawthorn.     

Pattern recognition of three Vitis vinifera L. red grapes varieties based on anthocyanin and flavonol profiles,with correlations between their biosynthesis pathways

The presence of anthocyanins and flavonols in three selected red grape varieties was investigated, in order to use their polyphenolic characterisation as a fingerprint. Berry skins of Gran Negro grapes were characterised by the presence of high content of malvidin- and peonidin-3-O-glucoside; Mouratón grapes, by the presence of high content of petunidin- and delphinidin-3-O-glucoside; and Brancellao grapes, by the presence of high content of cyanidin-3-O-glucoside. The main flavonols found included the 3-O-glucosides of quercetin, myricetin, kaempferol, laricitrin, isorhamnetin and syringetin. Using cluster analysis and principal components analysis, Gran Negro could be characterised by their content of isorhamnetin-3-O-glucoside and syringetin-3-O-glucoside and, along with Mouratón, by their myricetin conjugates. Flavonol profile could not provide a fingerprint of Brancellao variety. Stepwise discriminant analysis was performed in order to find the polyphenolic compounds, which characterised the selected grape varieties. Finally, anthocyanin and flavonol profiles in red grapes were compared and results confirmed that biosynthesis of flavonols is closely related to that of anthocyanins.