Important Source Of Polyphenols Research Articles

Tunisian Silybum Species: Important Sources of Polyphenols, Organic Acids, Minerals, and Proteins across Various Plant Organs.

Silybum marianum and Silybum eburneum are wild edible Mediterranean plants used in the human diet. This study presents the initial findings on the phytochemical characterization of Tunisian S. marianum and S. eburneum organs. It examined their mineral, sugar, organic acid, polyphenolic, and seed storage protein contents, as well as their antioxidant potential. In S. marianum, stems had high sodium and potassium contents, while the immature and mature seeds were rich in calcium and magnesium. However, S. eburneum had high potassium levels in stems and high sodium and calcium levels in the flowers. S. marianum showed substantial fructose variation among its organs. Conversely, S. eburneum exhibited significant heterogeneity in glucose, sucrose, and maltose levels across its organs, with maltose exclusively detected in the immature seeds. A notable organ-dependent distribution of organic acids was observed among the two species. Higher levels of phenolic contents were detected in both mature and immature seeds in both species compared to the other plant parts. The seeds possessed higher antioxidant activities than other plant organs. In both S. marianum and S. eburneum seeds, albumins and globulins were the predominant protein fractions. This study brings evidence supporting the important potential of Silybum organs as sources of nutrients with antioxidant properties for producing functional food.

Physicochemical Properties of Apple Purees and Peel Extract for Potential Use in Pastry Products

In recent years, the consumption of pastry and bakery products has grown considerably, and consumers are increasingly tempted to choose products from an organoleptic point of view. At the same time, consumers are also interested in having a healthy diet, respectively, products with special sensory properties, but with a low sucrose content. Substituting the sucrose in these products with apple puree represents an alternative to obtaining cakes with a lower sugar content and, in addition, in obtaining products with high nutritional value, with the bioactive compounds from apples having special properties on health. The purpose of this work was to analyze both the physicochemical properties, the total content of polyphenols and the antioxidant activity of the apple puree samples, as well as their variation during the storage period. The physicochemical properties analyzed were: moisture content, titratable acidity, ash content, pH, water activity, total soluble solids content and color. Regarding the content of the bioactive compounds, the total content of polyphenols and the antioxidant capacity were determined by the Folin–Ciocalteu method, respectively, the DPPH method. The results showed that apple puree is an important source of polyphenols, and these are the main factors influencing antioxidant activity. The analysis of the properties of the three products obtained from the apple will allow you to choose one of them or a combination of them in order to obtain the highest degree of sugar substitution and the highest nutritional value of the products. The degree of substitution will be correlated with technological parameters, baking temperature and time.

Estimated dietary intake of polyphenols from cereal foods and associated lifestyle and demographic factors in the Melbourne Collaborative Cohort Study

Cereal foods are consumed globally and are important sources of polyphenols with potential health benefits, yet dietary intakes are unclear. We aimed to calculate the dietary intakes of polyphenols from cereal foods in the Melbourne Collaborative Cohort Study (MCCS), and describe intakes by demographic and lifestyle factors. We estimated intakes of alkylresorcinols, lignans and phenolic acids in n = 39,892 eligible MCCS participants, using baseline dietary data (1990–1994) from a 121-item FFQ containing 17 cereal foods, matched to a polyphenol database developed from published literature and Phenol-Explorer Database. Intakes were estimated within groups according to lifestyle and demographic factors. The median (25th–75th percentile) intake of total polyphenols from cereal foods was 86.9 mg/day (51.4–155.8). The most consumed compounds were phenolic acids, with a median intake of 67.1 mg (39.5–118.8), followed by alkylresorcinols of 19.7 mg (10.8–34.6). Lignans made the smallest contribution of 0.50 mg (0.13–0.87). Higher polyphenol intakes were associated with higher relative socio-economic advantage and prudent lifestyles, including lower body mass index (BMI), non-smoking and higher physical activity scores. The findings based on polyphenol data specifically matched to the FFQ provide new information on intakes of cereal polyphenols, and how they might vary according to lifestyle and demographic factors.

Microwave-Assisted Extraction Optimization and Effect of Drying Temperature on Catechins, Procyanidins and Theobromine in Cocoa Beans.

Cocoa beans (Theobroma cacao L.) are an important source of polyphenols. Nevertheless, the content of these compounds is influenced by post-harvest processes. In this sense, the concentration of polyphenols can decrease by more than 50% during drying. In this study, the process of procyanidins extraction was optimized and the stability of catechins, procyanidins, and theobromine to different drying temperatures was evaluated. First, the effectiveness of methanol, ethanol, acetone, and water as extract solvents was determined. A Box-Behnken design and response surface methodology were used to optimize the Microwave-Assisted Extraction (MAE) process. The ratios of methanol-water, time, and temperature of extraction were selected as independent variables, whereas the concentration of procyanidins was used as a response variable. Concerning the drying, the samples were dried using five temperatures, and a sample freeze-dried was used as a control. The quantitative analyses were carried out by HPLC-DAD-ESI-IT-MS. The optimal MAE conditions were 67 °C, 56 min, and 73% methanol. Regarding the drying, the maximum contents of procyanidins were obtained at 40 °C. To our knowledge, this is the first time that the stability of dimers, trimers, and tetramers of procyanidins on drying temperature was evaluated. In conclusion, drying at 40 °C presented better results than the freeze-drying method.

The Effects of Grape Polysaccharides Extracted from Grape By-Products on the Chemical Composition and Sensory Characteristics of White Wines

There is an increasing interest in the valorization of wine waste by-products. Grape pomace/marc can be an important source of polyphenols but also of polysaccharides (PSs). Therefore, the aim of this work was to extract PSs from grape pomace and musts and incorporate them into wines to improve their quality and valorize these residues. Two white wines were elaborated and treated with four different PS extracts obtained from white grape pomace, white must, a wine purified extract rich in RG-II, and commercial inactivated yeasts. In general, the use of grape PSs extracted from grape pomace or must improve some characteristics of wine, increasing the polysaccharide and volatile concentrations. These PS extracts can be useful to modulate some taste attributes such as an excess of acidity and bitterness and can also prevent the loss of volatile compounds associated with fruity and floral notes over time. This is the first study that shows the effects of grape polysaccharides on the chemical composition and sensory characteristics of white wines. Considering the obtained results, the grape pomace and surplus of musts can be considered valuable sources to obtain polysaccharide-rich products, opening a new opportunity to take advantage of by-products from the wine industry.

Evaluation of acute toxicity, 28-day repeated dose toxicity, and genotoxicity of Moringa oleifera leaves infusion and powder

Ethnopharmacological relevanceMoringa oleifera Lam. leaves infusion and powder are widely used by population due the nutritional and medicinal potentials, however data regarding safety of use are still inconclusive, leading to prohibition of this plant in some countries. Aim of the studyThe present work investigated the nutritional and phytochemical composition, acute and 28-day repeated dose toxicity, and genotoxicity of M. oleifera leaves infusion and powder. Materials and methodsFor nutritional characterization of leaf powder, it was determined: humidity; mineral residue (ash); total lipid, protein, carbohydrate, and crude fiber contents; and total caloric value. Phytochemical composition was determined by high performance liquid chromatography (HPLC). The acute toxicity assay used Swiss female albino mice and oral administration in a single dose at 2000 and 5000 mg/kg of infusion or powder. The 28-day repeated dose toxicity assay employed female and male mice, with oral administration of infusion or powder at the doses 250, 500 and 1000 mg/kg. The animals were evaluated for body weight, water and feed consumption, biochemical and hematological parameters, and histology of the liver, spleen, and kidneys. In vivo genotoxicity and mutagenicity (2000 mg/kg) were evaluated by the comet assay and the micronucleus test, respectively. ResultsNutritional characterization confirmed that M. oleifera leaves are rich in proteins, carbohydrates, lipids, minerals, and fiber. HPLC indicated the presence of flavonoids and cinnamic derivatives as major polyphenols. Acute toxicity did not reveal alterations in weight gain and water and feed consumptions and no change in biochemical, hematological, and histological parameters. Behavior alterations was observed in the first 2 h after administration at 5000 mg/kg in both treatments. Infusion did not present toxicity when administered for 28 days. Conversely, the powder at 500 and 1000 mg/kg promoted liver and kidney damages observed through biochemical parameters and histopathology. Genotoxicity and mutagenicity were not detected at 2000 mg/kg. ConclusionsThe present study reveals that M. oleifera leaves are an important source of polyphenols and nutrients. Indiscriminate use of both infusion and crude leaf powder above 2000 mg/kg and powder at 500 and 1000 mg/kg are not recommended. Chronic toxicological studies and establishment of preparation protocols are suggested aiming to guarantee the safety in the use of M. oleifera leaves as nutraceutical by population.

Antioxidant Activity of Polyphenols, from Mauritia flexuosa (Aguaje), Based on Controlled Dehydration.

Plant polyphenols offer several benefits for the prevention of diverse illnesses. Fruit’s edible and inedible parts (pulp, seeds, peels, stems, flowers) are important sources of polyphenols. Different industrial processes for fruit treatment and commercialization affect the total polyphenol content (TPC), and probably the biological activity. The purpose of the present work was to determine the TPC and antioxidant activity (by DPPH) of polyphenols extracted from the pulp and seeds of Mauritia flexuosa (aguaje), in fresh and dehydrated forms, in order to determine the possible connection with the quantity of polyphenols and their specific antioxidant activity. The highest phenolic content for M. flexuosa seeds in fresh form (non-dehydrated) was 270.75 mg GAE/100 g with a 96-h extraction. With respect to the dehydrated samples, the best yield was quantified in the 96-h dehydrated seed sample. For all pulp and seeds, dehydrated for 24, 48, and 96 h, TPC showed a slightly decreasing pattern. The DPPH results were the highest in the 96-h dehydrated samples and the differences among all dehydrated pulp and seed samples were minimal. More studies testing the presence of other antioxidant components could help in understanding the detailed antioxidant activity, and related more to the specific action, rather than only total polyphenol content.

Comparative analysis of the total content of polyphenols in some types of industrial juice products

Fruits are the most important source of polyphenols, substances that have a positive effect on human health. Modern technologies for the industrial processing of fruits into juice are aimed at preserving the useful components of the raw material in it. The issue of the content of polyphenols in industrial juice products, and, especially, changes in their concentration over time, is important for understanding the nutritional value of juice products and requires further study. The purpose of the work is to study the total content of polyphenols depending on the type of juice products and the time elapsed since the product was manufactured. Material and methods. The total content of polyphenols in terms of gallic acid was determined by the Folin-Ciocalteu method in four popular types of juice products (orange, grapefruit and apple juice, cherry nectar), various brands and with different production dates. The results of the determination in 60 product samples selected from Russian retail chains were analyzed. Results. Polyphenols are found in all types of products in significant amounts: in orange juices from 678 to 870 mg/kg, in grapefruit juices from 447 to 798 mg/kg, in apple juices from 264 to 1320 mg/kg, in cherry nectars from 696 to 1090 mg/kg. The highest average content was found in cherry nectars (859±106 mg/kg), followed by orange (781±54 mg/kg) and grapefruit juices (634±91 mg/kg). In apple juices, there is a significant variation in the content of polyphenols depending on the method of juice production - the highest content of polyphenols was found in straight-pressed apple juices (1119±124 mg/kg). The content of polyphenols in products stored for six months or more does not show any significant differences from the content in fresher products, which suggests a consistently high content of polyphenols in juice products throughout the entire shelf life. Conclusion. The study showed the presence of high concentrations of common polyphenols in juice products. The dependence of total polyphenol content on the time elapsed since the production of juice product was not found. Juice products of industrial production can make a significant contribution to the intake of polyphenols in the human body.

Evaluation of the bioaccessibility of peanut skin polyphenols and their potential use for food enrichment

Polyphenols obtained from agricultural and industrial residues are also considered as remarkable sources of natural antioxidants to replace synthetic ingredients. In this study, the contents of total polyphenols (TP) and total flavonoids (TF), antioxidant capacity (AC) and in-vitro bioaccessibility of polyphenols (as gastric and intestinal stages) of the extract from peanut skin using water were investigated. Additionally, the potential use of peanut skin extract in noodle production was researched in order to add functionality to noodle, which is a widely consumed product. The results showed that 71.67 mg gallic acid equivalent (GAE)/g dry matter (DM) of TP, 123.11 mg rutin equivalent (RE)/g DM of TF and 66267.46 mmol ascorbic acid equivalent (AAE)/100g DM of AC were found in peanut skin. After the gastric and intestinal stages, the TP content and AC of the skin extract were found to be lower than the initial (before digestion) value. It was determined that polyphenols were more stable in gastric conditions than in the small intestine. The addition of the skin extract (0.4%) to the noodle dough increased the TP and AC of the final product compared to the noodle without the skin extract (control). It was observed that the stability of the polyphenols from the noodle sample was higher in gastric stage than intestinal one. The addition of peanut skin extract to the noodle dough increased the bioaccessibility of the polyphenols. Therefore, this study showed that peanut skin, as an important source of polyphenols, may be useful for food enrichment.

Vesicle-enhanced liquid-phase pulsed discharge extraction of polyphenols from green tea leaves

A vesicle-enhanced liquid-phase pulsed discharge (V-LPD) was proposed to extract polyphenols from green tea leaves. The optimal extraction conditions obtained by the process optimization were 3% (w/v) dodecyl trimethy lammonium bromide (DTAB)/sodium dodecyl sulfate (SDS) vesicle, 10% (v/v) ethanol/vesicle, 66 mL/g liquid-to-solid ratio, 5 kV discharge voltage, and 2.5 min extraction time. Under these optimal conditions, the polyphenols yield was 124.650 ± 1.197 mg/g, which was observably higher than that by heat reflux extraction (HRE) (108.156 ± 1.437 mg/g) for 45 min and that by ethanol-enhanced LPD (116.123 ± 1.164 mg/g) for 4 min. The energy consumptions of V-LDP and ethanol-enhanced LPD were far lower than that by HRE. Similar chemical constituents were observed by HPLC analysis in three extraction methods, and the extracts obtained by V-LPD had the highest antioxidant capacity. Therefore, the V-LPD is a time-saving and energy-saving method for the extraction of polyphenols. Industrial relevanceGreen tea is considered to be an important source of polyphenols. The potential of V-LPD has been demonstrated as a time-saving and energy-saving alternative using vesicle solvents for the simultaneous cell disruption and strengthening diffusion of polyphenols from green tea leaves. The polyphenols obtained with V-LPD process can be used in an array of pharmaceutical, cosmetic and food applications.

Anti-Inflammatory Activity of Oxycarotenoid Extracts Isolated from Coriander Leaves (Coriandrum Sativum) and Curry Leaves (Murraya koenigii) on Carrageenan Induced Acute Inflammation in Rats

Introduction: Green leafy vegetables are important sources of polyphenols and carotenoids which possess both antioxidant and anti-inflammatory activities. Aim: To study the anti-inflammatory activity of oxycarotenoid extracts isolated from coriander leaves (Coriandrumsativum) and curry leaves (Murraya koenigii) in carrageenan induced acute paw oedema in rats. Materials and Methods: Oxycarotenoid extracts were isolated from the coriander leaves (Coriandrum sativum) and curry leaves (Murraya koenigii) and they were assessed for anti-inflammatory activities by in-vivo methods. The in-vivo anti-inflammatory activity was evaluated in carrageenan induced acute paw oedema model. Indomethacin at a dose of 20 mg/Kg body weight was used as standard anti-inflammatory drug. Results: The results revealed that oxycarotenoids extracted from coriander leaves administered at a dose of 40 mg/kg body weight showed an inhibition of 53.33% whereas the oxycarotenoids extracted from curry leaves showed an inhibition of 60% at the sixth hour after carrageenan injection. The results are comparable with those of indomethacin (20 mg/Kg body weight) administered group which showed an inhibition of 55.53% Conclusion: These findings suggest that oxycarotenoid extracts isolated from leafy vegetables (coriander leaves and curry leaves) have significant anti-inflammatory activities.

Polyphenol content, profile, and distribution in old, traditional apple varieties

Apples are an important source of polyphenols in the human diet. They have also shown many potentially beneficial effects on human health. Old, traditional apple varieties grown in the past could also be valuable varieties but little is known about their polyphenolic compounds and characteristics in general. The aim of this study was to collect 25 old, traditional apple varieties, to determine their polyphenolic profile and the amounts of total polyphenols in the peel and flesh, and to compare them with a commercial variety. To the best of our knowledge, some of those varieties have never been studied before (‘Mašanka’, ‘Bobovac’, ‘Batulenka’, ‘Krastavka’). Total polyphenols were determined by using the Folin-Ciocalteu method and individual polyphenol identification was done by using an RP-HPLC. The flesh contained 170 to 941 mg kg-1 fresh weight (FW) of total polyphenols, and the peel contained 931 to 3791 mg kg-1 FW. In comparison to the commercial variety, the peel of all old varieties had higher polyphenol content, while the flesh of only some old varieties was richer in polyphenols. Principal component analysis showed possible clustering. Eighteen individual polyphenols were distributed in apple peel and flesh. The dominant polyphenol subgroups in the peel were flavonols (18 to 80 %) and flavan-3-ols (6 to 66 %), and in the flesh those subgroups were phenolic acids (41 to 85 %) and flavan-3-ols (3-49 %).

Phytochemical Profile of Capsicum annuum L. cv Senise, Incorporation into Liposomes, and Evaluation of Cellular Antioxidant Activity

Overproduction of oxidants in the human body is responsible for oxidative stress, which is associated with several diseases. High intake of vegetables and fruits can reduce the risk of chronic diseases, as they are sources of bioactive compounds capable of contrasting the free radical effects involved in cancer, obesity, diabetes, and neurodegenerative and cardiovascular diseases. Capsicum annuum L. cv Senise is a sweet pepper that is grown in the Basilicata region (Italy). It is an important source of polyphenols, carotenoids, and capsinoids and can play a key role in human health. In this study, an ethanol extract was obtained from C. annuum dried peppers and the analysis of the phytochemical composition was performed by LC-ESI/LTQ Orbitrap/MS. The extract was incorporated into liposomes, which showed small size (~80 nm), good homogeneity, negative surface charge, and good stability in storage. The biological activity of the extract was evaluated in the human hepatoma (HepG2) cell line, used as model cells. The extract showed no cytotoxic activity and reduced the intracellular reactive oxygen species (ROS) level in stressed cells. The antioxidant activity was further improved when the extract was loaded into liposomes. Moreover, the extract promoted the expression of endogenous antioxidants, such as catalase, superoxide dismutase, and glutathione peroxidase through the Nrf-2 pathway evaluated by RT-PCR.

Characterisation of polyphenols and antioxidant potential of red and white pomace by-product extracts using subcritical water extraction

A detailed assessment of the content of high added-value compounds in grape pomace varieties was carried out following a subcritical water extraction method. High amounts of anthocyanins and tannins were recovered from fermented grape pomace at differential temperatures with high variability between the by-products observed. Contrary to anthocyanins, high extraction temperatures (about 200 °C) yielded higher amounts of tannins. Overall, we found that grape pomace antioxidant activity and total polyphenols, quantified by the Folin Ciocalteu method, were not directly related to the main polyphenol content in SWE extracts. The data obtained in our study by using laboratory-scale equipment will be useful for developing an industrial-scale SWE process. Finally, it was shown that grape pomace by-products can be considered asan important source of polyphenols. They could therefore potentially provide a basis for the sustainable and integrated exploitation of winemaking by-products, to be used as inexpensive and readily available sources of bioactive compounds for the pharmaceutical, cosmetic and food industries.

Peel of Traditional Apple Varieties as a Great Source of Bioactive Compounds: Extraction by Micro-Matrix Solid-Phase Dispersion.

Micro matrix solid phase dispersion (micro-MSPD) was optimized by response surface methodology for the extraction of polyphenols from the peel of twelve traditional and eight commercial apple varieties grown in Croatia. The optimized micro-MSPD procedure includes the use of 0.2 g of sample, 0.8 g of dispersant, a 57% solution of methanol in water as the solvent and 5 mL of extract volume. The total polyphenolic index (TPI) and antioxidant activity (AA) were measured by spectrophotometric assays. Eighteen polyphenolic compounds were identified in all investigated apples by HPLC-DAD and LC-(ESI)-MS. The peel of traditional apple varieties had higher contents of all investigated polyphenols. Calculated relative contribution of polyphenol groups indicated non-flavonoids (28.6%) and flavanols (46.2%) as the major contributors to the total polyphenolic content in traditional and commercial apple varieties, respectively. The most abundant polyphenol in traditional apple peel was chlorogenic acid, procyanidin B2 and epicatechin (1143 ± 755 µg/g dw, 954 ± 343 µg/g dw and 560 ± 362 µg/g dw, respectively). The peel of varieties ‘Apistar’, ‘Bobovac’ and ‘Božićnica’ could be highlighted as an important source of polyphenols.

Cytotoxic, α-glucosidase, and antioxidant activities of flavonoid glycosides isolated from flowers of Lotus lanuginosus Vent. (Fabaceae)

Background: Lotus taxa (Fabaceae) were well known as an important source of polyphenols and flavonoids. Lotus lanuginosus Vent. is a widespread plant in the northern region of Saudi Arabia. Phytochemical and biological activities screening focusing of the species are rare. Objective: The objectives of this study were to isolate secondary metabolites from the flowers of L. lanuginosus Vent., elucidate their structures, and evaluate their biological activities. Materials and Methods: Chromatography methods of the n-butanolic extract of fresh flowers of L. lanuginosus led five products (1–5). Their structures were characterized based on spectroscopic evidence (ultraviolet, infrared, high-resolution mass spectrometry, and nuclear magnetic resonance) and compared to the spectral data signaled in the literature. Cytotoxic activities of the isolated compounds were evaluated against HCT-116 and MCF-7 cancer cell lines. α-glucosidase and antioxidant activities were also performed. Results: Five compounds were isolated and characterized for the first time in L. lanuginosus Vent.: Lotaustralin (1), kaempferol-7-O-α-L-rhamnopyranoside (2), kaempferol-3-O-apiofuranosyl-7-O-rhamnopyranosyl (3), isorhamnetin-3-O-rutinoside (4), and kaempferol-3-O-(2''-β-D-xylopyranosyl)-α-L-rhamnopyranoside-7-O-α-L-rhamnopyranoside (5). The results of cytotoxic activities against HCT-116 and MCF-7 cancer cell lines of the isolated compounds were presented. Among them, compounds 2 and 3 showed a moderate activity on HCT-116 cancer cells with half maximal inhibitory concentration values ranging between 8 and 31.5 μM. Moreover, compounds (2–5) displayed significant antioxidant and moderate α-glucosidase activities. Discussion and Conclusions: All the isolated products (1–5) are signaled for the first time in L. lanuginosus Vent. Among flavonoids glycosides, compound 2 showed the best cytotoxic activity. By the end of the present study, L. lanuginosus have been characterized as a highly cyanogenic plant and as an important source of polyphenols and flavonoids.

Polyphenol-Rich Extracts from Brown Macroalgae Lessonia trabeculate Attenuate Hyperglycemia and Modulate Gut Microbiota in High-Fat Diet and Streptozotocin-Induced Diabetic Rats.

Brown macroalgae are an important source of polyphenols with multiple health functions. In this work, polyphenol extracts from Lessonia trabeculate were purified and investigated for the antidiabetic activity in vitro and in vivo. The purified polyphenol extracts exhibited good antioxidant activities, α-glucosidase and lipase inhibition activities (IC50 < 0.25 mg/mL). The HPLC-DAD-ESI-MS/MS analysis indicated that the compounds in polyphenol extracts were mainly phlorotannin derivatives, phenolic acid derivatives, and gallocatechin derivatives. In vivo, C57BL/6J rats treated with polyphenol extracts for 4 weeks had lower fasting blood glucose levels, insulin levels, as well as better serum lipid profiles and antioxidant stress parameters, compared with the diabetic control (DC) group. Histopathology revealed that polyphenol extracts preserved the architecture and function of the liver. Short-chain fatty acid contents in rats' fecal samples with polyphenols administration were significantly recovered as compared with the DC group. Furthermore, the gut microflora of rats was investigated with high-throughput 16S rRNA gene sequencing and results indicated that polyphenol extracts had a positive effect on regulating the dysbiosis of the microbial ecology in diabetic rats. All of the results from the study provided a scientific reference of the potentially beneficial effects of L. trabeculate polyphenols on diabetes management.

Modeling of Total Phenolic contents in Various Tea samples by Experimental Design Methods

Abstract Tea, from the old ages to the day, is widely consumed both for enjoyment and health care due to its positive effects. The consumption of these products is increasing day by day as a result of the clear presentation of the fact that tea contains high amount of antioxidant substances (such as phenolic compounds), which is important in prevention and treatment of diseases. Tea beverage is a very important source of polyphenols. In this study, phenolic content and antioxidant capacity of different tea species were calculated by modeling with experimental design method. In the experimental part, polyphenol content was determined using the Folin-Ciocalteu method. The total amount of phenolic substance content was examined by Box-Behnken design and response surface method on black tea, green tea and white tea on different extraction temperature, extraction time and solid / liquid ratio. Solid / liquid ratio was found to be the most important parameter in terms of polyphenol content extraction from different tea samples. The highest polyphenol amount (411.762 mg gallic acid / mL) was found in green tea. To the best of our knowledge, this is the first data presenting comparatively study the effect of extraction condition on amounts of phenolic compounds from different tea samples.

Phenolic acids and antioxidant activity of wheat species: a review

Abstract Wheat (genus Triticum) is considered to be an important source of polyphenols, plant secondary metabolites with numerous health-promoting effects. Many phytochemicals are responsible for the high antioxidant activity of whole grain products. However, there is a lack of information about composition of phenolic acids and their concentrations in different Triticum species. Despite the fact that the increased consumption of whole grain cereals and whole grain-based products has been closely related to reduced risk of chronic diseases, bioactive compounds found in whole grain cereals have not achieved as much attention as the bioactive compounds in vegetables and fruits. Recent studies have revealed that the content of bioactive compounds and antioxidant capacity of whole grain cereals have been regularly undervalued in the literature, because they contain more polyphenols and other phytochemicals than was reported in the past. Phenolic acids represent a large group of bioactive compounds in cereals. These compounds play a significant role in the possible positive effects of the human diet rich in whole grain cereals, especially in wheat and provide health benefits associated with demonstrably diminished risk of chronic disease development. Ferulic acid, the primary and the most abundant phenolic acid contained in wheat grain, is mainly responsible for the antioxidant activity of wheat, particularly bran fraction. In this paper, selected phenolic compounds in wheat, their antioxidant activity and health benefits related to consumption of whole grain cereals are reviewed.

Improved LC-MSn characterization of hydroxycinnamic acid derivatives and flavonols in different commercial mate (Ilex paraguariensis) brands. Quantification of polyphenols, methylxanthines, and antioxidant activity

Yerba mate is a beverage rich in bioactive compounds popular in South America. Polyphenols and methylxanthines were qualitatively and quantitatively analyzed in four commercial brands of yerba mate, as well as the antioxidant capacity of the beverages. Using LC/MSn analysis, 58 polyphenols were observed of which 4-sinapoylquinic acid, di- and tri-methoxycinnamoylquinic acids, two isomers of trimethoxycinnamoylshikimic acid and four isomers of caffeoyl-2,7-anhydro-3-deoxy-2-octulopyranosonic acid were identified for the first time in mate. Additionally, 46 polyphenols and 2 methylxanthines were quantified by HPLC-DAD. Hydroxycinnamic acid derivatives and flavonols comprised 90% and 10% of mate phenols, respectively, 3-caffeoylquinic (26.8–28.8%), 5-caffeoylquinic (21.1–22.4%), 4-caffeoylquinic (12.6–14.2%) and 3,5-dicaffeoylquinic acids (9.5–11.3%) along with rutin (7.1–7.8%) were the most abundant polyphenols, whereas caffeine was the main methylxanthine (90%). Ilex paraguariensis is an important source of polyphenols with moderate methylxanthines content; therefore its high antioxidant capacity was mainly associated to its polyphenolic composition.