Selenium increases chlorogenic acid,chlorophyll and carotenoids of Lycium chinense leaves

BACKGROUND: Leaves of Lycium chinense L. are widely used in traditional Chinese medicine and as functional food in China and south‐east Asia. Polyphenols are important active compounds in leaves of L. chinense L, but their compositions are still not very clear. Selenium has been reported to increase some components of plants. In this study, the composition of polyphenols of L. chinense leaves were analysed, and the effects of selenium on the polyphenols and other components were studied. RESULTS: The main polyphenols were identified as rutin, chlorogenic acid, quercetin, kaempferol and apigenin‐7‐O‐(6′‐O‐acetyl) glucose‐rhamnose. Chlorogenic acid showed the highest average content of 78.36 g kg^?1. Rutin, quercetin and kaempferol were determined at low contents from 3.85 g kg^?1 to 7.08 g kg^?1. Correlation coefficients between selenium and chlorogenic acid, chlorophyll a, chlorophyll b and carotenoids were: R² = 0.963 (P = 0.002), 0.943 (P = 0.005), 0.957 (P = 0.003) and 0.943 (P = 0.005), respectively. Selenium (0.01–0.05 g kg^?1) significantly increased chlorogenic acid, chlorophyll and carotenoids by 200–400% and reduced rutin by 400–900%. CONCLUSION: L. chinense can be an alternative source of chlorogenic acid. Selenium significantly increased chlorogenic acid, chlorophyll a, chlorophyll b and carotenoids, hence increasing the medicinal value of L. chinense leaves. Rutin, quercetin, kaempferol and apigenin‐7‐O‐(6′‐O‐acetyl) glucose‐rhamnose proved to be not significantly influenced by selenium. Copyright © 2012 Society of Chemical Industry     

Bio-screening of a few green seaweeds from India for their cytotoxic and antioxidant potential

BACKGROUND: It has been evidenced in several epidemiological studies that seaweeds when consumed as diet protect against several chronic oxidative stress‐related diseases. Seaweeds, raw, cooked, or dried, are used as food in many cultures, although not very popularly in India. Globally, several studies have indicated that seaweeds are a rich source of phenolic compounds and have antioxidant properties. In the present study, we screened methanolic extracts (MEs) of five species of green seaweeds commonly found in India for their cytotoxic activity by brine shrimp lethality assay and antioxidant properties using various in vitro assays, including 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) radical scavenging, reducing power and metal ion chelating assays. RESULTS: A markedly variable, dose‐dependent activity was observed in all the seaweed extracts relative to their total phenolic content. Statistical analysis indicated a significantly strong correlation between the DPPH radical scavenging activity and total phenolic content (R² = 0.88, P < 0.05) as well as reducing power and total phenolic content (R² = 0.99, P < 0.01) of the dry MEs. Also, a very poor correlation between total phenolic content and metal chelating activity (R² = 0.13, P > 0.05) was noted. None of the seaweed extracts were potently cytotoxic. CONCLUSION: The underlying results endorse seaweeds as a rich, novel source of antioxidant compounds needing systemic exploration. Copyright © 2011 Society of Chemical Industry     

Dietary intake of anthocyanins and risk of cardiovascular disease: A systematic review and meta-analysis of prospective cohort studies

Abstract

Accumulating evidence suggests flavonoid intake is associated with reduced risk of non-communicable diseases. We aimed to systematically determine and quantify the potential association between dietary anthocyanin intake and risk of cardiovascular diseases (CVD). A systematic literature search of studies reporting anthocyanin intake and risk of fatal or nonfatal CVD was performed using SCOPUS, MEDLINE, CINAHL and Cochrane Library. The relative risk (RR) or hazard ratio (HR) of highest category of anthocyanin foods were pooled in a random-effects meta-analysis. Subgroup analysis were conducted to determine possible sources of heterogeneity. The meta-analysis suggested intake of dietary anthocyanins and reduced risk of CHD (RR?=?0.91, 95% CI: 0.83, 0.99; I²?=?12.0, P_h?=?0.337) and CVD mortality (RR?=?0.92, 95% CI: 0.87, 0.97; I²?=?0.0, P_h?=?0.584). However, there was no relationship between the intake of these compounds and reduced risk of MI, stroke or total CVD. Subgroup analysis determined reduced risk of CHD and CVD mortality was more prominent for anthocyanidin intake, as opposed to anthocyanin or berries. Our systematic review and meta-analysis provides evidence that anthocyanins, specifically anthocyanidins, reduce the risk of CHD and CVD mortality. Further randomized controlled trials on anthocyanin intake and CVD risk factors are needed to support these findings.     

Characterization of Brazilian lager and brown ale beers based on color, phenolic compounds, and antioxidant activity using chemometrics

BACKGROUND: Epidemiological studies have shown that beer has positive effects on inhibiting atherosclerosis, decreasing the content of serum low‐density lipoprotein cholesterol and triglycerides, by acting as in vivo free radical scavenger. In this research, the antioxidant activity of commercial Brazilian beers (n = 29) was determined by the oxygen radical absorbance capacity (ORAC) and 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH^·) assays and results were analyzed by chemometrics. RESULTS: The brown ale samples (n = 11) presented higher (P < 0.05) flavonoids (124.01 mg L^?1), total phenolics (362.22 mg L^?1), non‐flavonoid phenolics (238.21 mg L^?1), lightness (69.48), redness (35.75), yellowness (55.71), color intensity (66.86), hue angle (59.14), color saturation (0.9620), DPPH^· values (30.96% inhibition), and ORAC values (3, 659.36 µmol Trolox equivalents L^?1), compared to lager samples (n = 18). Brown ale beers presented higher antioxidant properties (P < 0.05) measured by ORAC (1.93 times higher) and DPPH (1.65 times higher) compared to lager beer. ORAC values correlated well with the content of flavonoids (r = 0.47; P = 0.01), total phenolic compounds (r = 0.44; P < 0.01) and DPPH (r = 0.67; P < 0.01). DPPH values also correlated well to the content of flavonoids (r = 0.69; P < 0.01), total phenolic compounds (r = 0.60; P < 0.01), and non‐flavonoid compounds (r = 0.46; P = 0.01). CONCLUSION The results suggest that brown ale beers, and less significantly lager beers, could be sources of bioactive compounds with suitable free radical scavenging properties. Copyright © 2010 Society of Chemical Industry     

Addition of enzymes complex during olive oil extraction improves oil recovery and bioactivity of Western Australian Frantoio olive oil

Olive oil consumption has increased as many studies revealed the health benefits of regular consumption of olive oil. There is a need to find effective oil extraction techniques capable of increasing oil recovery without compromising its quality. This study investigated the impact of adding enzymes complex Viscozymes during olive oil extraction on oil recovery, total phenolic compounds, antiradical activity and the standard quality parameters. It was found that at a concentration of 0.30 g mL^?1, Viscozymes could significantly improve the oil recovery from 49 to 69% (P < 0.001) when compared to the Control sample. The concentration of total phenolic compounds was also significantly improved from 110 to 266 mg kg^?1 oil (P < 0.01) and the antiradical activity increased from 31 to 48% inhibition of 2,2‐diphenyl‐1‐picrylhydrazil radical (P < 0.001). Addition of Viscozymes therefore represents an effective extraction technique that increases oil recovery without compromising the concentration of total phenolic compounds and antiradical activity.     

Biofortification with selenium and lithium improves nutraceutical properties of major winery grapes in the Midwestern United States

Enriching the micronutrients, selenium (Se) and lithium (Li), in grapes to improve their nutraceutical properties were implemented by foliar application of organic fertiliser rich in Se and Li onto five grape cultivars. The effects of this biofortification on vine vigour, fruit quality, overall micronutrients and phenolic compounds also were investigated. Agronomic biofortification was found greatly increased the Se and Li content in the whole grape by multiple times, meanwhile it did not significantly affect the vine vigour and fruit quality of grapes. However, the biofortification did impact the Ionome (including all the mineral nutrients and trace elements) and phenolic compounds in grapes and this varied among cultivars. This study demonstrated foliar spray of organic Se/Li fertiliser was a very effective strategy to biofortify these micronutrients in grape berries, particularly in the skin, and therefore might be a promising strategy to increase the consumption and awareness of these grapes.     

Qualitative and quantitative analysis of the major phenolic compounds as antioxidants in barley and flaxseed hulls using HPLC/MS/MS

BACKGROUND: Both qualitative and quantitative analyses of the major phenolic compounds in barley and flaxseed hulls were conducted using reverse phase high‐performance liquid chromatography coupled with photodiode array detection and quadrupole time‐of‐flight mass spectrometry. RESULTS: Ferulic acid, p‐coumaric acid, vanillic acid and vanillin were identified and quantified in four barley hull samples. Four ferulate dehydrodimers were also detected. The phenolic compounds of flaxseed hull were distinct from those of barley hull. Three flaxseed hull samples varied significantly (P < 0.05) in their contents of secoisolariciresinol diglucoside (16.38–33.92 g kg^?1), coumaric acid glucoside (35.68–49.22 g kg^?1) and ferulic acid glucoside (5.07–15.23 g kg^?1). The phytochemical profiles of co‐extracts featured the major phenolic compounds from both barley and flaxseed hulls. The total phenolic content and 2,2‐diphenyl‐1‐picrylhydrazyl radical‐scavenging capacity varied significantly (P < 0.05) among different varieties of flaxseed and barley hulls. CONCLUSION: As agricultural by‐products, barley and flaxseed hulls may be utilised as potential sources of functional food ingredients through extraction and concentration of the phytochemicals identified above. Copyright © 2012 Society of Chemical Industry     

ANTIOXIDANT PROPERTIES OF LENTINUS EDODES AND AGARICUS BLAZEI EXTRACTS

ABSTRACT

This work aimed to evaluate the antioxidant activity of Lentinus edodes and Agaricus blazei mushrooms, as well as to measure the content of total phenolic compounds of mushroom extracts and verify the oxidative stability of soybean oil added with mushroom extracts that showed higher antioxidant activity according to the methods of the 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH^•) free radical scavenging and the β‐carotene/linoleic acid system. According to the DPPH^• method, the maximum antioxidant activity for L. edodes and A. blazei methanol extracts was 92.84 and 95.10%, respectively. For the β‐carotene/linoleic acid system, the highest values of antioxidant activity were 93.06% for L. edodes and 78.96% for A. blazei. The content of total phenolic compounds ranged from 7.21 to 128.44 and 26.67 to 134.67 mg gallic acid equivalent/g for L. edodes and A. blazei, respectively. The oxidative stability values provided by the Rancimat method indicated that the two varieties presented similar induction period of 19.85 h.

PRACTICAL APPLICATIONS

Mushrooms present high content of antioxidant compounds that are capable of reducing the harmful effects of free radicals. Among the antioxidants present in mushrooms, phenolic compounds stand out as phenolic acids, flavonoids and tocopherols. To decrease or prevent lipid oxidation, synthetic antioxidants are used as food additives. Nevertheless, studies have revealed that these compounds are likely to pose risks to human health. The concern regarding the safety of synthetic antioxidants has motivated the search of natural antioxidants that can substitute them totally or partially.

     

Effects of drying temperature on the flavonoid,phenolic acid and antioxidative capacities of the methanol extract of citrus fruit (Citrus sinensis (L.) Osbeck) peels

There are many active functional compounds in citrus peels, such as flavonoid and phenolic acid. Scientists tried to obtain more bioactive components from citrus peels by various methods. This research investigated the effects of different drying temperatures (50, 60, 70, 80, 90 and 100 °C) on changes in the flavonoid, phenolic acid and antioxidative activities of citrus fruit (Citrus sinensis (L.) Osbeck) peels. The total phenolic and flavonoid contents of drying treated orange peels were decreased by lower drying temperature (50 and 60 °C) and increased by higher drying temperature (70, 80, 90 and 100 °C). Amounts of phenolic compounds in the 100 °C treated sample extract were significantly higher than the amounts in the samples heated at other temperatures (P < 0.05). EC₅₀ values of orange peel extracts by DPPH radical scavenging effects and ABTS^·+ scavenging effects were increased with lower drying temperature and decreased with higher drying temperature, and the values of 100 °C treated sample extract were significantly lower than the samples heated at other temperatures (P < 0.05). However, the chelating Fe^{2 +} activities of samples showed the opposite trend.     

Rice kernel phenolic content and its relationship with antiradical efficiency

Plant phenolics exert beneficial effects on human health and may also prevent oxidative deterioration of food. Two field experiments were carried out for characterising phenolics in rice. The first assay was conducted in 1999 and 2000 in Beaumont, TX and included five light‐brown, two purple and 10 red pericarp coloured cultivars. ‘Bran colour’ was highly statistically significant for both bran phenolic concentration and antiradical efficiency (p < 0.001). ‘Year’ and its interaction with bran colour were not significant for the analysed traits, suggesting that seasonal differences and their interactions may not affect phenolic content or antiradical efficiency. The accessions ranged from 3.1 to 45.4 mg gallic acid equivalents (GAE) g^?1 bran and from 10.0 to 345.3 µM trolox equivalents (TE) g^?1 bran for total phenolic content and antiradical efficiency respectively. The light‐brown bran genotypes exhibited the lowest values for phenolic content and antiradical efficiency, whereas red bran ones displayed ca 10 times higher total phenolic content and more than 50 times higher tannin content than light‐brown ones. The two purple lines showed either low or high values for the studied traits. Antiradical efficiency of rice bran extracts was highly positively correlated with total phenolic content (r = 0.99***), suggesting that phenolics are the main compounds responsible for the free radical‐scavenging activity in rice bran extracts. In the second field experiment (Stuttgart, AR, 2001 and Beaumont, TX, 2000), 133 coloured rice cultivars were analysed for total phenolic content in whole grain. The accessions showed a large variation for total phenolics, ranging from 0.69 to 2.74 mg GAE g^?1 grain. The data confirmed previous results suggesting bran colour as the main factor affecting phenolic concentration in rice kernel and seasonal effects and their interactions as not significant. The results also confirm that within red and purple bran groups can be found the highest phenolic concentrations in rice kernel. Published in 2004 for SCI by John Wiley & Sons, Ltd.     

Effects of seasoning on the formation of heterocyclic amines and polycyclic aromatic hydrocarbons in meats: A meta-analysis

Cooking improves digestibility, palatability, and microbiological profile of meats, but can produce compounds with carcinogenic potential, such as heterocyclic amines (HAs) and polycyclic aromatic hydrocarbons (PAHs). It has been shown that the formation of these compounds in meats can be inhibited by spiced marinades, but there is a complexity to check and compare the results of isolated studies with so many variables involved. Thus, this work aimed to review studies that evaluated the effects of spices on the formation of HAs and PAHs in meats according to cooking techniques and spice type. A meta-analysis with a random effect model was conducted using response ratios (R) to identify and summarize previous results and answer the research question. The use of spices before frying (R* = 0.52), grilling (R* = 0.63), or roasting (R* = 0.74) meat, and spicing with garlic and onion (R* = 0.57), pepper (R* = 0.63), and other spices with phenolic compounds (R* = 0.63), decrease the formation of HAs and PAHs, due to the antioxidant and electron transfer capacity. In this article, we discuss how the improvement of culinary techniques with the dissemination of knowledge about meat preparation conditions is an effective strategy for reducing the formation and ingestion of HAs and PAHs; this is important due to the growing evidence about the association between meat consumption and chronic diseases. This is the first systematic review with meta-analysis about this topic and can guide industry, food services, and population to improve the safety associated with meat consumption.     

Assessment of endogenous antioxidative compounds and antioxidant activities of lager beers

BACKGROUND: Flavour stability is increasingly becoming the limiting factor in the shelf life of beer. Increasing the antioxidant activity of beer itself could suppress the rate of oxidative reaction and improve the flavour stability of beer. This report describes the levels of phenolic compounds, melanoidins and sulfur dioxide, and antioxidant activities of 40 lager beers. The relationships between antioxidative compounds and antioxidant activity were elucidated by multivariate analysis techniques. RESULTS: The results showed that the total phenolic content and the melanoidins content correlated well (P < 0.05) with antioxidant activity, while there was no significant correlation (P > 0.05) between total sulfur dioxide content and antioxidant activity. Satisfactory discrimination among beer samples with significantly different antioxidant activity was achieved by principal component analysis. Results from stepwise linear regression further demonstrated that different antioxidative components responsible for antioxidant activity were dependent on the assay used. The phenolic compound group is by far the most antioxidative compounds in beer and total phenolic content, melanoidins and sulfur dioxide together made a 22–68% contribution to the antioxidant activities of beers. CONCLUSION: Therefore, it might be an efficient means for brewers to increase total phenolic content during brewing for improvement in flavour stability of the final beer. © 2012 Society of Chemical Industry     

Purification and identification of rambutan (Nephelium lappaceum) peel phenolics with evaluation of antioxidant and antiglycation activities in vitro

The crude rambutan peel phenolic (RPP) extracts were purified by resin adsorption technology. NKA‐9 resin with the best adsorption capacity and desorption ratio was chosen to dynamically purify crude RPP. Adsorption capacity and desorption ratio of NKA‐9 resin were 91.85 mg gallic acid equivalent (GAE) g^?1 and 90.45%, respectively. Purification processes enriched total phenolic content, and the contents in crude and purified RPP were 579.72 and 877.11 mg GAE g^?1 extract powder, respectively. Phytochemical compounds of RPP were qualitatively and quantitatively indentified by mass spectrometry. Purification of the resin as expected elevated the concentrations of major phenolic compounds, especially geraniin and ellagic acid. Antioxidant and antiglycation activities of crude and purified fractions were evaluated in vitro. Crude and purified RPP had high inhibitory effects on oxidation and glycation, and purified RPP showed stronger bioactivity than crude RPP (P < 0.05), which might be due to their differences in phenolic profiles.     

Phenolic acids from malt are efficient acetylcholinesterase and butyrylcholinesterase inhibitors

Anticholinesterase activities of mashes produced using wheat (‘Wheat Pale’) or barley malts (‘Pilsner’, ‘Pale Ale’, ‘Munich Light’, ‘Carahell’ or ‘Carared’) were studied by spectrophotometric method. The highest inhibition of acetylcholinesterase and butyrylcholinesterase was observed at 52 °C and/or 64 °C, followed by a decrease or stabilization of the activity at 72 °C. Changes in the total phenolics content in the test mashes were correlated with changes in the acetylcholinesterase and/or butyrylcholinesterase activities. Phenolic acids were singled out from phenolic compounds for more detailed studies owing to their simplicity and structural similarity to well‐known cholinesterase inhibitors. The main phenolic acids in the test malts were ferulic, gallic, p‐coumaric and vanillic acids followed by chlorogenic, caffeic, syringic, p‐OH‐benzoic, sinapic and protocatechuic acids. The anticholinesterase activities of the phenolic acids were studied using model standard solutions at concentrations similar to the maximal content of these compounds in the test mashes. Among the phenolic acids, p‐coumaric acid had the largest share in the anticholinesterase activity, even though it was present in the test mashes at a significantly lower concentration (~0.38 mm L^?1) than ferulic acid (~1.00 mm L^?1). Sinapic acid and p‐OH‐benzoic acid (0.03 and 0.01 mm L^?1, respectively) were equally efficient inhibitors as ferulic acid at ~1.00 mm L^?1. This preliminary study should be extended to other phenolic compounds from malt (wort) in the near future. Copyright © 2012 The Institute of Brewing & Distilling     

A systematic review on phenolic compounds in Passiflora plants: Exploring biodiversity for food,nutrition, and popular medicine

Passiflora plants are strategic in the context of biodiversity for food and nutrition. We applied the procedures of a systematic review protocol to study the state of the art on identification of phenolic compounds from Passiflora plants. An automated literature search was conducted using six databases and a combination of seven keywords. All the analytical, chromatographic, and spectroscopic methods were included. The studies were classified according to their method of identification, phenolic classes, and method of extraction. In total, 8,592 abstracts were found, from which 122 studies were selected for complete reading and 82 were selected for further analysis. Techniques of extraction, evaluated parts of the plant and methods of identification were systematized. Studies with leaves were most conspicuous (54.4%), 34 species of Passiflora were evaluated and orientin, isoorientin, vitexin, isovitexin were commonly found structures. A High Performance Liquid Chromatography-diode array detector was the technique most applied, with which the same structures were identified all through the studies, although other unknown structures were detected, but not elucidated. The use of Nuclear Magnetic Resonance and Mass Spectrometry, which are more sensitive techniques, needs to be intensified, to identify other unconventional compounds detected in Passiflora, to enhance the comprehension of the bioactive compounds in these plants.     

A correlation between the level of phenolic compounds and the antioxidant capacity in cooked-with-rice and vegetable soybean (Glycine max L.) varieties

This study was undertaken to determine the content of phenolic compounds contained in embryo, cotyledon and seed coat of nine soybean (Glycine max L.) varieties. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity was also measured to determine the correlation between the level of phenolic compounds and antioxidant capacity. A total of 10 anthocyanin constituents and 21 phenolic compounds was detected and quantified. In all nine varieties, the seed coat and cotyledon had the highest and lowest levels of phenolic compounds and anthocyanins, respectively despite the fact that all of them showed a wide variation in total amounts of phenolic compounds and anthocyanins in seed coat, embryo, and cotyledon. The seed coat tissue, but not other seed parts, showed a strong correlation between the seed coat color and the content of both phenolic compounds and anthocyanins. The brown and black soybean seed coat contained much higher levels of phenolic compounds and anthocyanins in seed coat tissue than the yellow or green coat soybean. Among the individual phenolic compounds, syringic acid (214 μg g⁻¹) and chlorogenic acid (31 μg g⁻¹) were highest in seed coat and embryo, respectively. Myricetin was highest both in whole seed (16.7 μg g⁻¹) and cotyledon (16.0 μg g⁻¹), being equivalent to 20 and 30% of total phenolic compounds, respectively. Among the 10 anthocyanins, cyanidin-3-glucoside was found to accumulate at the highest level in the seed coat (1783 μg g⁻¹), whole seed (106 μg g⁻¹) and embryo (0.35 μg g⁻¹), which correspond to 95, 96, and 40% of the total anthocyanin contents, respectively. The cotyledon accumulated pelargonidin-3-glucoside (0.39 μg g⁻¹) at the highest level that is equivalent to 62% of total anthocyanin contents. DPPH activity was found to have a strong correlation (^***probability < 0.001) with phenolic compounds (0.67^***) and anthocyanins (0.70^***).J. A. Kim, W. S. Jung, and S. C. Chun are equally contributed to this work.     

Sacha inchi (Plukenetia volubilis L.) shell: an alternative source of phenolic compounds and antioxidants

Sacha inchi seed (SI) is known as a rich source of oil with high content of polyunsaturared fatty acids of the ω‐3 and ω‐6 type (~85% of total fatty acids). However, few studies have focused on the use of by‐products from the seed. The aim of this study was to characterise the main phenolic families present in SI shell and to evaluate the best extraction solvent for the extraction of phenolic compounds (PC) and antioxidant capacity (AOXC). The PC content corresponded to 74.5 ± 5.1 mg g^?1 of which 93.1% were condensed tannins and the remaining compounds corresponded to free and bound phenolic acids, hydrolyzable tannins, flavonoids and flavanoids. Protocatechic and p‐coumaric acids but also hydroxycinammic acid derivatives of ferulic and o‐coumaric type and lignan derivatives were identified. Acetone containing solvents favoured the extraction of higher amounts of total PC and AOXC. This study highlights the potential use of SI shell as a novel and alternative source of PC antioxidants for the nutraceutical and/or functional food industries.     

Selected bioactivities of Vaccinium berries and other fruit crops in relation to their phenolic contents

Antioxidant activity, urinary tract protective activity, and cardioprotective anti‐platelet effects are among the bioactivities associated with dietary phenolics. These bioactivities were measured in vitro in fruit extracts from seven Vaccinium species and five non‐Vaccinium species to determine their relationship to total phenolic content and to anthocyanin and proanthocyanidin content. Berries belonging to the genus Vaccinium were particularly high in antioxidant activity and urinary tract protective anti‐adhesion activity, while anti‐platelet activity varied among species. There was a positive relationship between antioxidant activity (using the oxygen radical absorbing capacity (ORAC) assay) and both the total phenolic (R² = 0.76) and anthocyanin content (R² = 0.43) of the fruit, although there was no relationship between ORAC and proanthocyanidin content. There were no relationships between anti‐adhesion activity and total phenolic content, anthocyanin content, or proanthocyanidin content. Likewise, no relationships were observed between anti‐platelet activity and total phenolic content, anthocyanin content, or proanthocyanidin content. These results suggest that while antioxidant properties are characteristic of all fruit phenolics, in vitro anti‐adhesion and anti‐platelet bioactivities may be due to less abundant phenolic subgroups. Copyright © 2007 Crown in the right of Canada and Society of Chemical Industry     

Red clover (Trifolium pratense L.) isoflavones: root phenolic compounds affected by biotic and abiotic stress factors

BACKGROUND: Phenolic compounds have recently received considerable attention for their ability to protect plant and human cells from oxidative stress‐induced damage. Red clover (Trifolium pratense L.) is a rich source of isoflavonoids with multiple potential protective functions. The aim of this study was to identify and characterise phenolic compounds in red clover roots by high‐performance liquid chromatography and mass spectrometry and to study the effects of stress factors and growth stage on root phenolics. RESULTS: A total of 28 phenolic compounds were tentatively identified in red clover roots. The most abundant phenolics in pot‐grown roots were formononetin glycoside malonate (G‐M) (1.51–4.26 mg g^?1), formononetin (2.21–3.57 mg g^?1) and biochanin A (1.73–2.17 mg g^?1), whereas field‐grown roots were rich in formononetin‐G‐M (3.90–4.27 mg g^?1), maackiain‐G‐M (2.35–3.02 mg g^?1) and pseudobaptigenin‐G‐M (1.80–2.58 mg g^?1). Concentrations were affected by the growth stage. Ozone exposure slightly affected the total phenolic content in roots and also had minor effects on individual compounds. CONCLUSION: Elevated ozone, cultivation regime and growth stage affected the levels of phenolics in red clover roots, suggesting sensitivity of root phenolics to biotic and abiotic stress conditions. The high levels of phenolics found in roots even in late autumn may be utilised in many applications. Copyright © 2009 Society of Chemical Industry     

Comparative content of some phytochemicals in Spanish apples,peaches and pears

Dietary fibre, total polyphenols and phenolic acids in Spanish apples, peaches and pears were analysed and compared with their total radical‐trapping antioxidative potential (TRAP). There were no significant differences in the content of dietary fibre among the studied fruits. The content of total polyphenols was 2.4 ± 0.4, 2.1 ± 0.3 and 6.9 ± 0.7 g kg^?1 in peeled fruits and 4.7 ± 0.4, 4.5 ± 0.4 and 11.1 ± 1.2 g kg^?1 in their peels for peaches, pears and apples respectively. The contents of dietary fibre, total polyphenols, caffeic, p‐coumaric and ferulic acids and the TRAP values were significantly (P < 0.05) higher in peels than in peeled fruits. The contents of all studied compounds and the TRAP values were significantly higher in peeled apples and their peel than in peaches and pears. We observed a strong correlation between the contents of total polyphenols and phenolic acids and the total radical‐trapping antioxidative potential in all three fruits. The relatively high content of dietary fibre, the highest contents of total polyphenols, caffeic, p‐coumaric and ferulic acids and the highest value of TRAP make apples preferable among the studied fruits for dietary prevention of atherosclerosis and other diseases. © 2002 Society of Chemical Industry