Phenolic profile,antioxidant and antiproliferative activity of black and red currants (Ribes spp.) from organic and conventional cultivation

The effect of cultivation system on phenolic profile, antioxidant capacity and antiproliferation activity in black and red currants was evaluated. Results from this study showed that Ribes fruit grown in organic system posses significantly higher total phenolics, especially anthocyanins, and antioxidant activity (DPPH and FRAP) than fruit grown in conventional system. Phenolic compounds were systematically identified and characterised by UPLC/MS Q‐TOF. The mean value of total polyphenol content in organically grown currants was similar but statistically higher compared with the conventional cultivation (11831.0 and 1543.0 mg/kg of d.m., respectively). The total values of the anthocyanins in ‘Ben Hope’, ‘Ben Alder’, ‘Titania’ and ‘Rondom’ from organic and conventional farms were 1044.5 vs. 1012.4; 1568.3 vs. 1260.4; 1417.2 vs. 1382.2; and 51.8 vs. 57.9 mg kg^?1 of d.m., respectively. Conventionally grown red currant had higher anthocyanin content than organically grown red currant (11.8%) but, however, organic fruits of red currant had 2.7 times higher content of oligomeric procyanidins than fruits coming from conventional cultivation. DPPH radical scavenging activity of currant varied from 28.29 to 37.08 mmol Trolox kg^?1 (mean 31.20) for organic fruits and from 12.67 to 31.18 mmol Trolox kg^?1 (mean 25.76) for conventional fruits. Moreover, all currants from organic cultivation possess higher ferric reducing capacity than conventionally grown fruits. It appeared that extracts of red Ribes cv. ‘Rondom’ coming from organic cultivation revealed stronger antiproliferative effect in comparison with conventional cultivation. However, a similar profile of activity was observed for ‘Ben Hope’, ‘Ben Alder’ and ‘Titania’ independently of the type of cultivation. These results indicate that the cultivation technique had important effect on the ranking of the cultivar systems.     

Effect of dehydration on phenolic compounds and antioxidant activity of blackcurrant (Ribes nigrum L.) pomace

This study examined the effect of dehydration on the phenolic compounds and antioxidant activity of blackcurrant (Ribes nigrum L.) pomaces (DBP) subjected to hot air oven drying (HOD), industrial rotary drying (IRD) and freeze drying (FD). Temperature and residence time were evaluated for HOD, whereas air-on and air-off temperature, ratio of drum rotor speed to air speed and particle size were evaluated for IRD. The highest total anthocyanins (ATC) and flavonols (FLV) were obtained in particle size of> 5.0 mm using IRD at 475°C/97°C (air-on/air-off) and higher ratio of drum rotor speed to air speed. Smaller size particles were found susceptible to degradation due to high temperature and retention time applied in IRD, resulting in loss of phenolic compounds in DBP, and thus, HOD was deemed more suitable. Overall, drying method selection and parameters of operation are key in preserving the concentrations of individual HCA and FLV in DBP.     

Quality parameters and antioxidant properties in organic and conventionally grown broccoli after pre‐storage hot water treatment

BACKGROUND: Demand for broccoli has increased due to its high content of bioactive compounds. However, broccoli is a perishable commodity with a short shelf life mainly due to dehydration, yellowing and losses of bioactive compounds. Thus, efficient treatments to preserve broccoli quality are needed. RESULTS: The effect of heat treatment on senescence and antioxidant compounds evolution during storage at 20 °C was evaluated in organic and conventionally grown broccoli. Senescence evolved quickly as manifested by floral head yellowing, which was higher in conventional than in organic broccolis, but senescence was significantly delayed by heat treatment. All organic acids, including ascorbic acid, were found at higher concentrations in organic than in conventional broccoli at harvest but decreased during storage in all broccolis. Phenolic concentration and antioxidant activity (in both hydrophilic and lipophilic fractions) also decreased during storage, although these decreases were higher in conventional than in organic broccolis, and no differences were found attributable to heat treatment. CONCLUSIONS: Heat treatment was effective in delaying broccoli senescence, manifested by chlorophyll retention. In addition, organic broccoli maintained higher concentrations of bioactive compounds (ascorbic acid and phenolics) and antioxidant potential during storage than conventional broccoli, with higher potential health beneficial effects. © 2012 Society of Chemical Industry     

Antioxidant activity of black currant (Ribes nigrum L.) extract and its inhibitory effect on lipid and protein oxidation of pork patties during chilled storage

This experiment was conducted to assess the antioxidant efficacy of black currant (Ribes nigrum L.) extract (BCE) in raw pork patties during chilled storage. The extracting conditions of frozen BCE including ethanol concentrations (0-100%) and extracting times (0.25-12h) were studied. BCE extracted with 40% ethanol for 2h had the highest anthocyanin content, the strongest radical scavenging activities as well as the second strongest reducing power. BCE was condensed and added to pork patties at 5, 10 or 20 g/kg. Compared with the control, BCE treatments significantly decreased the thiobarbituric acid-reactive substance values and carbonyls formation and reduced the sulfhydryl loss of pork patties in a dose-dependent manner (P<0.05), which showed that the BCE significantly inhibited lipid and protein oxidation. The BCE-treated patties showed significantly higher redness (P<0.05) than the control. The findings demonstrated strong potential for BCE as a natural antioxidant in meat and meat products.     

Influence of Aging Process on the Bioactive Components and Antioxidant Activity of Ginseng (Panax ginseng L.)

The effects of aging process on the ginsenosides and antioxidant activity of ginseng was investigated. Fresh ginseng roots were aged in oven at 70 or 80 °C for 7, 14, 21, or 28 d. Their ginsenosides, phenolics, and antioxidant activity were analyzed. Ginseng aged at 80 °C for 14 d exhibited the highest amounts of total saponins and phenolics. It also showed markedly higher free radical scavenging activity, reducing power, and ferrous ion chelating ability than the other aged ginsengs. The ginsenosides Rb₁, Rb₃, Rg₃, Re, Rg₁, and Rg₂ were generated during aging. The Rg₂ was the most abundant ginsenoside in aged ginseng, with samples treated at 80 °C for 14 d having the highest amount. These findings provide the first evidence that aging, particularly at 80 °C for 14 d, could increase the bioactive compounds, indicating that this heating process may be useful in enhancing the biological activity of ginseng.     

HPLC-DAD-ESI-MS/MS Analysis and Antioxidant Activities of Nonanthocyanin Phenolics in Mulberry (Morus alba L.)

ABSTRACT:  Qualitative analysis of the nonanthocyanin phenolics from 2 mulberry cultivars, da-10 and hongguo, was performed by the HPLC-DAD-ESI-MS/MS method. Six nonanthocyanin phenolics compounds were identified (procatechuic acid, chlorogenic acid, 4-caffeolyquinic acid, taxifolin, rutin, quercetin) and 3 others (3,5-diCQA, taxifolin-hexoside, kamepferol-hexoside) were tentatively identified. Quantification of nonanthocyanin phenolic was performed by HPLC-DAD, which revealed that rutin (111.38 and 90.79 μg/g FW) was the major nonanthocyanin phenolics in the 2 mulberry cultivars. Phenolic acids in cultivar da-10 (54.68 μg/g FW) were far more than in cultivar hongguo (14.93 μg/g FW). CQA and its isomers (40.02 μg/g FW) were the major phenolic acid in cultivar da-10. The nonanthocyanin phenolics in the 2 cultivars of mulberry had higher antiradical activities in superoxide anion and DPPH radical and antioxidant activity in β-CLAMS assay than the Trolox. These results were relevant to not only the control of color stability and organoleptic characteristics of mulberry juice and wine but also the exploitation of the functional foods made from mulberry.     

Accumulation of phenolics,antioxidant and antiproliferative activity of sweet corn (Zea mays L.) during kernel maturation

Phenolic profiles and gene expression pattern in their synthetic pathway, total antioxidant activities and antiproliferative activities in two genotypes of sweet corn (YT16 and YT28) during kernel maturation were analysed. Results showed that increasing trends of phenolics and flavonoids in the two genotypes of kernels from 10 to 30 days after pollination (DAP). Gallic acid, chlorogenic acid, p-coumaric acid and ferulic acid were identified and quantified as the main phenolic compounds in both genotypes of kernels. High expressing levels of C4O and PAL resulted in the increasing phenolic contents. Higher expressing levels of CHS in YT28 led to higher flavonoid contents than that in YT16. The phenolic contents, antioxidant capacities and antiproliferative abilities of the two genotypes of sweet corn were competitive comparing to many fruits and vegetables. In addition, the maturation process of sweet corn could raise the kernel’s bioactive ability as well as nutritional values.     

Control of post‐harvest brown rot on nectarine by Epicoccum nigrum and physico‐chemical treatments

Post-harvest physico-chemical treatments—water at 40 °C or 60 °C (HW), and sodium bicarbonate at 1 or 2.5% (SBC) at 20, 40 and 60 °C—were tested on peaches and nectarines in order to control brown rot caused by Monilinia spp. and to select the best physico-chemical treatment to be used in combination with pre-harvest applications of the biological control agent Epicoccum nigrum (ATCC number 96794). Experiments were carried out in France, Italy and Spain in order to test different experimental conditions. Monilinia rot was reduced in peach and nectarine treated with HW (40 °C for 2 min) in all three countries, the percentage of rot reduction was similar for France, Italy and Spain (over 40%). A synergistic effect between HW at 40 °C during 150 s or at 60 °C during 20 s and SBC was observed in all three countries. After preliminary experiments post-harvest treatment of HW (60 °C) + SBC (1%) during 20 s was selected to combine it with field treatments. Pre-harvest treatments with fungicide or E. nigrum did not reduce brown rot in any country. However, pre-harvest treatments with E. nigrum, chemical fungicide, and their integration followed by post-harvest physico-chemical treatment significantly reduced Monilinia rot compared to pre-harvest untreated fruits followed by post-harvest physico-chemical treatment in Italy (over 70%). Post-harvest treatments with E. nigrum were also tested in Italy on natural and artificial infections in nectarine over 3 years. E. nigrum, as fresh or formulated cells, at a concentration of 10⁸ conidia mL⁻¹ were effective, significantly reducing the incidence of brown rot compared to control, both under artificial and natural infection, from 43 to 100%. Copyright © 2007 Society of Chemical Industry     

Salt effect on phenolics and antioxidant activities of Tunisian and Canadian sweet marjoram (Origanum majorana L.) shoots

BACKGROUND: Two varieties of Origanum majorana (Canadian and Tunisian) were evaluated for their phenolic, flavonoid and tannin contents, individual phenolic compounds and antioxidant activities under NaCl constraint. RESULTS: The results showed a significant variability in phenolic composition and antioxidant behavior between the two varieties under salt stress. The phenolic composition of methanolic extracts was determined by reversed‐phase high‐performance liquid chromatography. Amentoflavone was the predominant flavonoid compound; in addition, trans‐2‐hydrocinnamic acid became the major phenolic acid with salt treatment of the Tunisian variety. In the control, Canadian variety extract was characterized by high levels of gallic acid and amentoflavone. However, under 75 mmol L^?1 NaCl, gallic acid content doubled, whereas amentoflavone content was maintained in the Canadian variety. Stimulation of phenolic acid biosynthesis was observed in these two varieties under salt treatment despite the fact that shoots of the Tunisian variety showed higher antioxidant activities compared to those from the Canadian variety. Tunisian O. majorana might have developed tolerance to salinity and avoided tissue damage by activating enzymes involved in the galactosylation of quercetin into quercetin‐3‐galactoside and quercetin‐3‐rhamnoside. CONCLUSION: Our results confirmed the tolerance of Tunisian O. majorana plants. Copyright © 2012 Society of Chemical Industry     

The influence of harvest time on essential oil composition,phenolic constituents and antioxidant properties of Turkish oregano (Origanum onites L.)

BACKGROUND: The aim of this research was to determine essential oil composition, phenolic constituents and antioxidant properties of Turkish oregano (Origanum onites L.) leaves harvested during the months of June to September. RESULT: The maximum essential oil yield in the leaves appeared in the middle of July. The main components of oregano oil were carvacrol, thymol, γ‐terpinene, p‐cymene, α‐terpinene and α‐pinene. Carvacrol was highest in the July harvest. The maximum extract yield was found in September. Oil distilled from early‐season (June) harvested leaves had the highest antioxidant ability, expressed as low concentration providing 50% inhibition of free radical scavenging activity and high levels of reducing/antioxidant capacity. Twelve phenolic compounds of oregano extract were identified and the main components were found to be rosmarinic acid and acecetin. The maximum rosmarinic acid and acecetin were found in harvests of July and June, respectively. Total phenolic contents, free radical scavenging activities and reducing/antioxidant capacities were found to be highest in the July harvest. DISCUSSION: All yields, chemical compositions, free radical scavenging activities and reducing/antioxidant capacities of extracts and essential oils of Turkish oregano changed importantly depending on vegetative periods of growing season. Copyright © 2009 Society of Chemical Industry     

Effect of differently processed açai (Euterpe oleracea Mart.) on the retention of phenolics and anthocyanins in chewy candies

This study investigated the effects of processing and storage on the physicochemical properties and retention of antioxidant compounds of no‐added sucrose chewy candies (NASC) incorporated with differently processed açai (frozen pulp, spray‐dried and freeze‐dried powders). NASC containing freeze‐dried açai had the highest softness and recoveries of total phenolic (TP) and total anthocyanin (TA) immediately after production. Colour parameters and antioxidant capacity by ABTS and ORAC assays had no significant differences after 6 months of NASC storage, except for ORAC in NASC containing spray‐dried açai, whereas DPPH^? in all samples significantly increased. Water activity and hardness also increased after storage, whereas TP and TA contents decreased, despite presenting good retentions (approx. 72–78% TP and 84–99% TA). This study suggests that açai has a great potential to be used as a natural pigment and antioxidant source in candy manufacturing, meeting consumption trends towards healthier products.     

Phenolics and antioxidant capacity of table grape (Vitis vinifera L.) cultivars grown in Chile

Grapes (Vitis vinifera L.) possess health-promoting effects attributed to their supply of a wide variety of bioactive phenolics. Juice and skin fractions of 4 varieties of table grapes: Red Globe, Crimson Seedless, Autumn Royal, and Ribier were prepared to determine and compare their total phenolics content, antioxidant capacity (DPPH, FRAP, and ORAC), anthocyanins, and specific phenolics (caffeic acid, gallic acid, resveratrol, and catechin) content, since a series of positive health benefits are expected from the intake of any of these fractions. Higher amounts of total phenolics and antioxidant capacity were observed in the skin fractions (P < 0.05). Blue grapes (Autumn Royal and Ribier) exhibited higher phenolics content and antioxidant capacity (P < 0.05) than red grapes. The most abundant phenolic compound observed was catechin (P < 0.05). Significant correlations between the antioxidant capacity and total phenolics were observed in grape juice and skin fractions. Autumn Royal juice provides a very high amount of phenolics, anthocyanins, and exhibits the highest antioxidant capacity, offering the best health promoting properties compared with the other grape varieties studied. PRACTICAL APPLICATION: Grapes possess health-promoting effects attributed to their supply of a wide variety of bioactive phenolics. Grape juice made with blue grapes (Autumn Royal, Ribier) exhibit higher phenolics content and antioxidant capacity than juice elaborated with red grapes (Red Globe, Crimson Seedless). The skin is a good source of phenolics and has a high antioxidant capacity. Specific health-promoting phenolics are more abundant in blue grapes, mainly in their skin fraction, which should not be discarded.     

Effect of pre‐harvest salicylic acid spray treatment on post‐harvest antioxidant in the pulp and peel of ‘Cara cara’ navel orange (Citrus sinenisis L. Osbeck)

BACKGROUND: Exogenous salicylic acid (SA) pretreatment could change the antioxidant system and maintain the nutritional value of fruits and vegetables, which have a higher ability to withstand oxidation injuries. However, the relationship between a pre‐harvest SA spray and post‐harvest antioxidant compounds in fruit remains unknown. RESULTS: The post‐harvest behaviour of antioxidant compounds in ‘Cara cara’ navel orange (Citrus sinenisis L. Osbeck) fruit was investigated in relation to the pre‐harvest SA applications. Pre‐harvest SA treatment significantly increased the content of carotenoids (lycopene and α‐carotene), ascorbic acid, glutathione, total phenolics, and total flavonoids in the pulp and peel during storage. Furthermore, the values of these antioxidant compounds were high in the fruit treated with high SA concentrations (1.0 and 2.0 mmol L^?1). High antioxidant activity was also observed in the SA pre‐harvest treated fruit when compared with the control. The positive relationships were found between the antioxidant activity and the content of these active compounds. CONCLUSION: These results indicated that SA could maintain fruit antioxidant activity and nutrition which was shown by the increase in content of antioxidant compounds and suggested that pre‐harvest treatment with SA promised a novel technology, which was a substitute for the perplexing programme control of post‐harvest nutrition in fruit. Copyright © 2007 Society of Chemical Industry     

丝瓜花不同溶剂提取物抗氧化活性及其酚类成分分析

以无水乙醇、70%乙醇、40%乙醇和水分别对丝瓜花进行提取,并测定各提取物中总酚、总黄酮含量,采用DPPH·清除能力、超氧化物自由基清除能力、FRAP抗氧化能力和亚铁离子螯合能力等方法评价其抗氧化活性,通过HPLC分析其中酚类成分。结果表明,70%和40%乙醇提取物总酚及总黄酮含量较高,而且DPPH·清除活性、FRAP还原力最强,40%乙醇提取物、水提物分别具有最强的超氧阴离子自由基清除活性和亚铁离子螯合能力。总酚含量与DPPH·清除活性之间存在较强的相关性(R²=0.8688)。HPLC分析检出提取物中9种酚类化合物,其中含量最高的为杨梅素。试验结果说明,70%乙醇、40%乙醇可能是丝瓜花抗氧化性物质提取的较好溶剂。结果表明丝瓜花是一种较好的抗氧剂资源。     

Exogenous methyl jasmonate diminishes the formation of lipid‐derived compounds in boiled potato (Solanum tuberosum L.)

BACKGROUND: During potato storage the tubers tend to develop off‐flavours, mainly due to lipid‐derived aldehydes, whose formation is increased after boiling or processing. This may become a problem when boiled or precooked potatoes are used. Methyl jasmonate (MJ) is a phytohormone capable of modifying plant and food composition. The aim of this work was to control the formation of off‐flavours in different cultivars of raw potato during storage by MJ treatment. RESULTS: The use of Carbowax 20M as support in MJ emulsion resulted in significantly (P < 0.05) lower levels of lipid‐derived compounds than the use of lanolin. Levels of the lipid‐derived aldehydes propanal, hep‐2‐enal, nonanal, oct‐2‐enal and hexanal, although dependent on variety, generally decreased significantly (P < 0.05) after treatment with MJ/Carbowax 20M emulsion. Sugar‐derived compounds such as pyridine and furfural, however, were not affected by this treatment. CONCLUSION: Treatment with MJ/Carbowax 20M can be used to diminish the formation of off‐flavours in boiled potato. However, this treatment is not useful to avoid the sweetening caused by sugar‐derived products. Additional advantages of exogenous MJ are a delay in the appearance of sprouting and aging and hence prolongation of the storage life of potato tubers. Copyright © 2010 Society of Chemical Industry