Phenolic and antioxidant composition of cider

Forty-four Asturian ciders were analysed for total phenolic content, phenolic profiles, and antioxidant capacity by the FRAP and the DPPH radical assays. The Folin index of ciders ranged between 446 and 1180 mg gallic acid/L. The phenolic profile of Asturian cider is mainly constituted by phenolic acids, flavan-3-ols, volatile phenols and dihydrochalcones. The methods to determine the antioxidant activity of ciders were optimised in terms of suitable reaction times, within-day and between-day repeatability. Thus, time courses of ciders in the DPPH and the FRAP assays were performed. Mean values for antioxidant activity of cider, expressed in ascorbic acid equivalents were 2.9 mM (as determined by the DPPH assay). When the FRAP assay was used, the antioxidant capacity of cider increased with the reaction time from 3.8 mM (4 min) to 5.4 mM (40 min). Multivariate approaches based on phenolic composition can be useful to predict the antioxidant capacity of cider. Folin index and flavanols and hydrocaffeic acid contents were the best predictors for antioxidant activity.     

Radical scavenging,antioxidant and metal chelating activities of Annona cherimola Mill. (cherimoya) peel and pulp in relation to their total phenolic and total flavonoid contents

This study aimed to evaluate the total phenolic and flavonoid content, radical scavenging activity (by DPPH and ABTS tests) and antioxidant capacity (by β-carotene bleaching test) of Annona cherimola (cherimoya) fruits cultivated in Italy for human consumption. The metal chelating activity and ferric reducing power were also determined. A. cherimola peel and pulp were characterized by a total phenolic content of 14.6 and 12.6 mg chlorogenic acid equivalents/100 g fresh weight, respectively. A similar trend was observed with flavonoid content. Both extracts exhibited high antioxidant activity through different mechanisms of action. In particular, peel extract demonstrated the strongest free radical scavenging activity with an IC₅₀ value of 57.7 μg/mL. The same extract was more effective in preventing β-carotene oxidation (IC₅₀ value of 63.5 μg/mL after 60 min) and showed higher chelating ability (IC₅₀ value of 79.6 μg/mL) than pulp extract. This work demonstrated the high quality of cherimoya fruits cultivated in Italy, and recommends the peel of this fruit product that may be of interest from a functional point of view as a major source of natural antioxidants.     

Antioxidant activity of methanolic extract of emblica fruit (Phyllanthus emblica L.) from six regions in China

The phenolic contents of methanolic extracts of emblica (Phyllanthus emblica L.) fruit from six regions in China were measured in this work. The antioxidant activities of these extracts were also evaluated. Total phenolic content was ranged from 81.5 to 120.9 mg gallic acid equivalents (GAE)/g and the flavonoid content was varied from 20.3 to 38.7 mg quecetin equivalents (QE)/g, while proanthocyanidin content was ranged from 3.7 to 18.7 mg catechin equivalents (CE)/g. Among all the methanolic extracts analyzed, the Huizhou sample exhibited a significantly higher phenolic content than other samples (P<0.05). The antioxidant activities were evaluated by in vitro experiments using scavenging assays of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, hydroxyl radicals, and superoxide anion radicals, chelating ability of ferrous ion, reducing power, and inhibition capability of Fe (II)-induced lipid peroxidation, respectively. The Huizhou sample was found to have the strongest antioxidant activities in scavenging DPPH radicals, superoxide anion radicals, and had the highest reducing power, while the Chuxiong sample showed the best performance in chelating iron and inhibiting lipid peroxidation. Furthermore, the Chuxiong sample exhibited a stronger inhibition activity of the hydroxyl radicals compared with other samples. The high correlation coefficient was existed between the phenolic content and superoxide anion radical scavenging activity, but no significant correlation was found between the former and hydroxyl radical scavenging activity. Methanolic extracts of emblica fruit from some selected regions exhibited stronger antioxidant activities compared to those of the commercial compounds (quercetin and BHA). It might be considered as a potential plant source of antioxidants.     

Anthocyanin profile and antioxidant capacity of black carrots (Daucus carota L. ssp. sativus var. atrorubens Alef.) from Cuevas Bajas,Spain

The present work deals with the study of the anthocyanin profile of two different black carrots (Daucus carota L. ssp. sativus var. atrorubens Alef.) cultivars, associated with Antonina and Purple Haze varieties, from Cuevas Bajas (Málaga, Spain) and some of their antioxidant features. The main anthocyanins detected by LC–MS were found to correspond to five cyanidin-based anthocyanins: cyanidin 3-xylosylglucosylgalactoside, cyanidin 3-xylosylgalactoside and the sinapic, ferulic and coumaric acids derivative of cyanidin 3-xylosylglucosylgalactoside. The anthocyanins present in the black carrots were essentially acylated and their levels were found to correspond to 25% and 50% of the total phenolic content for the Purple Haze and Antonina varieties, respectively. Moreover, the reducing capacity of the two black carrots extracts (86.4 ± 8.0 and 182.0 ± 27 μM TE/100 g fw) and the radical scavenging ability (17.6 ± 9.0 and 240.0 ± 54.0 μM TE/100 g fw) expressed in Trolox equivalents units were determined. The antioxidant features of the black carrot extracts were shown to be significantly higher than those of orange carrots used herein for comparison. Overall, this work highlights the Cuevas Bajas black carrots as rich sources of anthocyanins with significant antioxidant capacities and good nutritional value.     

Antioxidant activity and recovery of green tea catechins in full-fat cheese following gastrointestinal simulated digestion

Green tea extract (GTE) was incorporated into full-fat cheeses at 250, 500, and 1000 ppm to investigate the effect of green tea catechins on antioxidant properties and microstructure of cheese, and recovery of catechins. Cheeses were ripened for 90 days at 8 °C followed by simulated gastrointestinal digestion. The composition on Day 0, and pH, total phenolic content (TPC), and antioxidant activity (AA) of the cheeses on Days 0, 30, and 90, were determined. The concentrations of the major GTE catechins in the curd and from the digesta of mature cheeses were determined using HPLC. Addition of GTE significantly (p ≤ 0.05) decreased the pH of whey and curd during cheese manufacture and ripening, however there was no significant (p > 0.05) effect on moisture, protein, or fat contents. Addition of GTE increased TPC and AA at all concentrations, but in a non-linear manner. Individual catechins were selectively retained in the curd, whereas different portions were recovered from the cheese digesta. Transmission electron microscopy showed that the ripened control cheese had a regular distribution of milk fat globules entrapped in a homogeneous structure of casein proteins, which was disrupted by GTE. Interactions between green-tea catechins and cheese fat were confirmed by Fourier transform infrared spectroscopy.     

Antioxidant activity,quality parameters and mineral content of Portuguese monofloral honeys

Physicochemical properties (pH, free, lactonic and total acidity, electrical conductivity and moisture), main mineral content (potassium, sodium, calcium, magnesium and iron) and antioxidant activity (total phenolics, 1,1diphenyl-2-picrylhydrazyl radical scavenging and ferric reduction antioxidant power) were determined for 39 Portuguese monofloral honeys (rosemary, orange, thyme, arbutus, locust podshrub and heather) with different geographical origins. Portuguese honeys showed good chemical and nutritional qualities fulfilling the criteria described in Directive 2001/110/CE. Potassium was the main mineral component representing 85% of total minerals. The mineral composition of sodium (4.63–200.60 mg/kg), calcium (0.43–72.30 mg/kg), magnesium (3.05–82.20 mg/kg) and iron (below 7.06 mg/kg) were higher for heather, eucalypt and arbutus honeys. Monofloral honeys of arbutus (Arbutus unedo), locust podshrub (Ceratonia siliqua L.) and heather (Erica umbellata) showed higher antioxidant activity with phenolic contents higher than 600 mg gallic acid equivalents (GAE)/kg, a DPPH scavenging activity higher than 50% and a ferric reduction antioxidant power above 600 μM Fe²⁺. Furthermore, the chemometric analysis revealed that total phenolic content was a crucial variable explaining the antioxidant activity of arbutus and locust podshrub honeys characteristic of the south of Portugal.     

Antioxidant activity of different white teas: Comparison of hot and cold tea infusions

The study investigates the antioxidant characteristics of various white teas steeped in either hot or room-temperature water in relation to grade of tea and brewing conditions. Antioxidant activity, chelating activity, total phenol (TPC), flavonoids (TFC), theaflavins and individual catechin content were examined. The results confirm that extraction of tea leaves carried out with water at room temperature leads to the formation of infusions particularly rich in compounds with antioxidant activity. In fact, for all the white teas studied, cold infusions had a higher content of phenols (4.77–7.63 mmol/L Gallic Acid Equivalents, GAE), flavonoids (1.47–2.53 mmol/L Catechin Equivalents, CE) and catechins (441.5–1328.2 μg/mL) compared to hot infusions (1.43–4.02 mmol/L GAE, 0.70–1.13 mmol/L CE, 83.4–534.8 μg/mL, respectively). The same trend was also observed for antioxidant activities examined using the ABTS assay (cold: 17.09–34.23; hot: 5.26–17.07 mmol/L Trolox Equivalents) and by monitoring the effects of the infusions on LDL oxidation (lag time, cold: 172.4–271.2; hot: 88.4–145.9 min). A general trend in antioxidant activity and in polyphenolic compound content can be delineated between Chinese teas, i.e. Bai Mu Dan ≥ Xue Ya ≥ White Lung Ching > Anji Needle Mao Feng > Yhin Zhen Bai Hao and between African teas, i.e. White Salima Peony > Thyolo Bsp > Bvumbwe Bsp. Concerning metal chelating activity, all the white teas displayed similar levels (0.3–0.6 mmol/L EDTA Equivalents) with no significant differences between the hot and cold infusions (except Bvumbwe Bsp and Thyolo Bsp). This paper contains key information on the antioxidant properties, TPC, TFC, and individual catechin content of several white teas commercially available and the outcomes suggest that preparing tea infused in room temperature water for approximately 2 h may constitute an alternative tea beverage potentially richer in healthful bioactive compounds compared to the more commonly consumed hot tea infusions.     

Phenolic compounds and antioxidant activity of Spanish commercial grape juices

Evaluation of the antioxidant activity of components of the diet is important in order to establish healthy consumption patterns. Data are reported here on the antioxidant activity (FRAP and ABTS), of 20 commercial grape juices and 10 typical Spanish wines and on their content of total phenolic compounds, anthocyanins, flavonoids and 10 individual phenolic compounds (flavanols, benzoic acids and cinnamic acids, measured by HPLC-UV). Red grape juices had a significantly higher (p < 0.05) concentration of total phenols (1177 vs. 744 mg gallic acid/L), flavonoids (98 vs. 63 mg catechin/L) and a higher antioxidant activity (9.16 vs. 2.83 meq Trolox/L) in comparison to white grape juices. In comparison to the white wines, white grape juices contained more total phenols (744 vs. 286 mg gallic acid/L) and flavonoids (63 vs. 29 mg catechin/L) and evidenced higher antioxidant activity (p < 0.05). In comparison to the red wines, a lower content of total phenols (286 vs. 2358 mg gallic acid/L) and flavonoids (228 vs. 29 mg catechin/L) and an absence of anthocyanins were observed in the white wines, which are therefore less antioxidant. Although a two-fold higher concentration of antioxidant compounds was found in red wines than in red grape juices, the latter may be a good option for all age groups because of the absence of alcohol and the potentially beneficial health effects of their phenolic composition and elevated antioxidant activity.     

Total phenolic compounds and antioxidant potential of Hedychium spicatum Buch. Ham. ex D. Don in west Himalaya,India

Total phenolic compounds and antioxidant potential of Hedychium spicatum were analyzed for 16 different natural populations located in Uttarakhand (west Himalaya) for promotion as health or medicinal food. Total phenolic compounds varied among populations from 4.70 mg gallic acid equivalent (GAE) to 2.84 mg GAE/g dry weight. Three in vitro antioxidant assays, i.e. azinobisethylbenzothiazoline-6-sulphonic acid radical scavenging (ABTS) assay, diphenyl-2-picrylhydrazyl (DPPH) assay and ferric reducing antioxidant power (FRAP) assay, showed significant (p < 0.05) differences across populations. ABTS assay showed highest values of antioxidant potential ranging from 2.581 mM ascorbic acid equivalent (AAE) per 100 g to 1.91 mM AAE per 100 g dry weight, followed by FRAP assay (1.921–0.6635 mM AAE per 100 g). Lowest values were observed for DPPH assay, which varied from 0.549 to 1.059 mM AAE per 100 g dry weight. All assays (ABTS, DPPH and FRAP) showed significant (p < 0.05) correlation with total phenolic compounds. Total phenolic compounds showed a significant relationship (p < 0.05) to altitude.     

Dietary fiber,phytochemical composition and antioxidant activity of Mexican commercial varieties of cactus pear

Cactus pear is one of the most important fruit in Mexican culture; however the phytochemical characterization of the whole cactus pear (pulp, peel and seeds) has not been studied. Therefore, the goal of this research was to evaluate the dietary fiber, vitamin C, total phenolic (TP), flavonoid and betalain concentrations and antioxidant activity (AOX) in the pulp, juice, peel and seeds of four Mexican commercial varieties of cactus pear. Rojo Cenizo and Rojo San Martín pulps presented concentrations of total dietary fiber, vitamin C, TP, betalains, and AOX of 145–166 g, 3–7 g ascorbic acid, 3–6 g gallic acid equivalents (GAE), 500–3444 mg betanin equivalents and 1044–5954 mg indicaxanthin equivalents, and 46–67 mm Trolox equivalents (TE) per kg, respectively. Rojo San Martín peel presented TP content over two times greater than the pulp, whereas AOX levels of Rojo San Martín and Verde Villanueva peels were 4–9 higher than their respective pulp. Cactus pear peel was the most important source of phytochemical compounds and AOX of the fruit, because of that it has to be considered in future applications for the formulation of new health-promoting ingredients and/or foods.     

Development of HPLC method for Cyclopia subternata phenolic compound analysis and application to other Cyclopia spp.

Analysis of phenolic compounds in Cyclopia spp. (honeybush) is very important because of commercial interest in the plant material as an herbal tea and in extracts for the nutraceutical and cosmeceutical markets. An existing HPLC-DAD method was adapted and proved reproducible as evidenced by good intra- and inter-day precision. The method allows the quantification of several well-known as well as unidentified phenolic compounds. Its suitability for quantification of the major phenolic compounds present in the water extracts of unfermented and fermented Cyclopia subternata, Cyclopia intermedia, Cyclopia genistoides and Cyclopia sessiliflora was evaluated. Known compounds that were identified and quantified include mangiferin (0.1–11.8 g/100 g), isomangiferin (0.1–3.2 g/100 g), eriocitrin (not detected–0.4 g/100 g), hesperidin (0.2–1.2 g/100 g) and scolymoside (not detected–1.8 g/100 g), while narirutin and luteolin were detected in most samples, but could not be quantified due to low concentrations and co-elution. An unidentified compound (traces–4.8 g hesperidin equivalents/100 g), unidentified hydroxycinnamic acid derivative (not detected–0.3 g mangiferin equivalents/100 g), unidentified flavanone (not detected–2.0 g hesperidin equivalents/100 g) and an eriodictyol-glycoside (not detected–0.5 g hesperidin equivalents/100 g) could also be quantified. Large variation was observed within a sample series of the same extract type due to the nature of the plant material. Qualitative and quantitative differences were observed between species, while “fermentation”, a high-temperature process involving non-enzymatic oxidation, decreased the content of most phenolic compounds. Results using DAD as the only detection method should be handled with care, as the tentative identification of compounds 9 and 10, based on retention time and UV–Vis spectrum, could not be confirmed using liquid chromatography–electrospray ionisation-mass spectrometry.     

The effect of black tea on risk factors of cardiovascular disease in a normal population

ObjectivesA prospective randomized controlled clinical trial determined the effect of Mauritian black tea consumption on fasting blood plasma levels of glucose, lipid profiles and antioxidant status in a normal population.MethodsThe study group (71%) consumed 3 x 200 ml of black tea infusate/day for 12 weeks without additives followed by a 3 week wash-out. The control group (29%) consumed equivalent volume of hot water for same intervention period.ResultsThe tea used had high levels of gallic acid derivatives (50 ± 0.4 mg/L), flavan-3-ols (42 ± 2 mg/L), flavonols (32 ± 1 mg/L) and theaflavins (90 ± 1 mg/L). Daily 9 g supplementation of black tea infusate induced, in a normal population, a highly significant decrease of fasting serum glucose (18.4%; p < 0.001) and triglyceride levels (35.8%; p < 0.01), a significant decrease in LDL/HDL plasma cholesterol ratio (16.6%; p < 0.05) and a non significant increase in HDL plasma cholesterol levels (20.3%), while a highly significant rise in plasma antioxidant propensity (FRAP: 418%; p < 0.001) was noted .ConclusionBlack tea consumed within a normal diet contributes to a decrease of independent cardiovascular risk factors and improves the overall antioxidant status in humans.     

Phytochemical composition of nuts

Observational studies suggest nut consumption is inversely associated with the incidence of cardiovascular disease and cancer. In addition to being rich in several vitamins and minerals, unsaturated fatty acids, and fiber, tree nuts and peanuts contain numerous phytochemicals that may contribute to promoting health and reducing the risk of chronic disease. While many of these bioactive constituents remain to be fully identified and characterized, broad classes include carotenoids, phenols, and phytosterols. Phytosterols in nuts range from 95-280 mg/100 g. alpha- and beta-Carotene, beta-cryptoxanthin, lutein, and zeaxanthin are found in microg/100 g amounts in some nuts but at 1-3 mg/100 g in pistachios and none at all in Brazils, macadamias, and peanuts. Phenols, including phenolic acids, flavonoids, and stilbenes, are present in nuts. Walnuts are particularly rich in total phenols with 1625 mg gallic acid equivalents/100 g. The stilbene resveratrol is found in peanuts and pistachios at 84 and 115 microg/100 g, respectively. The flavonoid content of nuts as provided in USDA Database for the Flavonoid Content of Selected Foods, lists totals in pecans at 34, almonds at 15, and pistachios and hazelnuts at 12 mg/100 g. Proanthocyanidins are found in almonds, cashews, hazelnuts, pecans, pistachios, peanuts, and walnuts, with concentrations varying from 9-494 mg/100 g. Nut phytochemicals have been associated with numerous bioactivities known to affect the initiation and progression of several pathogenic processes. However, as complete phytochemical profiles are lacking for most nuts, information is limited regarding their bioavailability and metabolism, so further research on this topic is warranted.     

In vitro antioxidant activities of Stevia rebaudiana leaves and callus

Leaf extract of Stevia rebaudiana promotes effects on certain physiological systems such as the cardiovascular and renal and influences hypertension and hyperglycemia. Since these activities may be correlated with the presence of antioxidant compounds, leaf and callus extracts of Stevia rebaudiana were evaluated for their total phenols, flavonoids content and total antioxidant capacity. Total phenols and flavonoids were analyzed according to the Folin–Ciocalteu method and total antioxidant activity of water and methanolic extracts of stevia leaves and callus was assessed by ferric reducing/antioxidant power (FRAP) assay as well as 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. The total phenolic compounds were found to be 25.18 mg/g for stevia leaves and 35.86 mg/g for callus on dry weight basis. The flavonoids content was found to be 21.73 and 31.99 mg/g in the leaf and callus, respectively. The total antioxidant activity was expressed as mg equivalent of gallic acid, ascorbic acid, BHA and trolox per gram on dry weight basis. Total antioxidant activity found was ranged from 9.66 to 38.24 mg and 11.03 to 36.40 mg equivalent to different standards in water and methanolic extract of stevia leaves, respectively. In case of stevia callus, it was found to be 9.44 to 37.36 mg for water extract and 10.14 to 34.37 mg equivalent to standards for methanolic extract. The concentrations required for 50% inhibition (IC₅₀) of DPPH radicals were 11.04, 41.04 and 57.14 μg/mL for gallic acid, trolox and butylated hydroxyanisole (BHA), respectively. The percent inhibition of DPPH radical of various extracts of stevia leaves and callus found were ranged from 33.17% to 56.82%. The highest percent of inhibition was observed in methanolic extract of callus.     

Effect of solvents in extracting polyphenols and antioxidants of selected raw vegetables

Thirty-seven raw vegetables were extracted using four solvent systems: 70% acetone, 70% ethanol, 70% methanol, and distilled water. The extracts were tested for their total phenolic content, total flavonoid content and antioxidant activities (using diphenylpicryl-hydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays). The results revealed the effect of different extracting solvents in altering the quantitative analyses of all vegetables and 70% acetone was identified as the most efficient solvent for extracting polyphenolic antioxidants from the vegetables. The highest total phenolic content and total flavonoid content were obtained from 70% acetone extract of Portulaca oleracea (138.2 ± 2.1 mg GAE/g dw basis) and 70% methanol extract of Cosmos caudatus (27.7 ± 1.0 mg QE/g dw basis), respectively. The 70% acetone extract of Etlingera elatior with moderate amount of total phenolic content exhibited the highest antioxidant activity in both assays. The correlation analyses within 37 different extracts of each solvent extraction demonstrated weak to moderate relationships between all the studied parameters. The highest r value of 0.7139 (p < 0.001) was determined between total phenolic contents and FRAP values of the 70% methanol extracts. Meanwhile, a wide range of correlation coefficients was derived from correlation analyses within four different extracts of each vegetable, with the highest relationship between total phenolic contents and FRAP values for the extracts of Coriandrum sativum (r = 0.9998, p < 0.001).     

Soluble and insoluble oxalate content of nuts

This study was conducted to determine the oxalate contents in common nuts either locally grown or imported into New Zealand. Samples of imported nuts were purchased from supermarkets in Christchurch while locally grown nuts were obtained directly from the growers. In this experiment gastric soluble and intestinal soluble oxalates were extracted from the nuts using an in vitro assay, which involved incubations of the food samples for 2 h at 37 °C in gastric and intestinal juice. The extracted oxalates were then determined by HPLC chromatography. Roasted pistachio nuts and chestnuts contained very low levels (<85 mg/100 g fresh weight (FW)) of gastric soluble oxalate. Peanuts, Spanish peanuts, peanut butter, ginkgo, cashew nuts and pecan nuts all contained relatively low levels of gastric soluble oxalate (147–250 mg gastric soluble oxalate/100 g FW). Almonds, Brazil, pine and candle nuts contained high levels of gastric soluble oxalate (492.0–556.8 mg/100 g FW). The intestinal soluble oxalate is the fraction that will be absorbed in the small intestine. Peanuts, Spanish peanuts, peanut butter, ginkgo and pecan nuts all contained relatively low levels of intestinal soluble oxalate (129–173 mg intestinal soluble oxalate/100 g FW). Almonds, Brazil, cashew and candle nuts contained higher levels of intestinal soluble oxalate (216–305 mg/100 g FW). Pinenuts contained the highest levels of intestinal soluble oxalate (581 mg/100 g FW), while chestnuts and roasted pistachio nuts were low (72 and 77 mg /100 g FW). Overall the mean soluble oxalate contents of nuts was 78% of the gastric soluble oxalate content (41–100%). The results obtained in this study confirm that the intestinal soluble oxalate contents of nuts range widely and people who have a tendency to form kidney stones would be wise to moderate their consumption of certain nuts.     

Sweet cherry phytochemicals: Identification and characterization by HPLC-DAD/ESI-MS in six sweet-cherry cultivars grown in Valle del Jerte (Spain)

Individual anthocyanin pigments and phenolic compounds were isolated, identified and quantified in six different sweet-cherry cultivars (Prunus avium L.) grown in Valle del Jerte area (Spain). An extractive-chromatographic method has been optimized for one-step extraction and simultaneous determination of all the studied components by HPLC/DAD-MS. The highest levels of phytochemicals were found in the autochthonous sweet-cherry cultivars that belong to the Protected Designation of Origin (POD) Cereza del Jerte. Van cultivar showed the lowest level of anthocyanin pigments and phenolic compounds. The most abundant anthocyanin pigment in all the studied cultivars was cyanidin-3-rutinoside (105 mg/100 g fresh weight (fwt) in Pico Negro sweet-cherry cultivar). The most abundant phenolic compound was the flavanol p-coumaroylquinic acid (130 mg/100 g fwt in Pico Negro sweet-cherry cultivar). In addition, chemical attributes (antioxidant activity, soluble solid content and pH) were also evaluated.     

Determination and evaluation of element bioaccessibility in some nuts and seeds by in-vitro gastro-intestinal method

Element bioaccessibility in some nuts and seeds has been determined by performing a physiologically based extraction test. Nine elements (B, Ca, Co, Cu, Fe, Mn, Mg, Ni and Zn) in gastric and intestinal phase extractions of nuts and seeds were determined using inductively coupled plasma-atomic emission spectrometry and inductively coupled plasma-mass spectrometry. Hazelnuts, almonds, sunflower seeds, peanuts, cashew nuts, Brazil nuts, walnuts, chickpeas, pumpkin seeds and pistachio nuts were used as the materials in this study. The bioaccessible portions of magnesium and calcium were higher than for the other elements whereas B bioaccessibility was the lowest for each of the different types of nuts and seeds. Based on an ingestion rate of 10 g day⁻¹, the amounts of B, Ca, Co, Cu, Fe, Mn, Mg, Ni and Zn from the nuts and seeds accessible to the body were found to be lower than the Tolerable Upper Intake Levels. The data were also subjected to chemometric evaluation using tools such as Principal Component Analysis (PCA) and Linear Discriminant Analyses (LDA) in an attempt to classify the nuts and seeds according to these elements bioaccessibility and to find out which elements are more bioaccessible in gastric and intestinal ingestions.     

Effects of cooking on in vitro sinigrin bioaccessibility,total phenols,antioxidant and antimutagenic activity of cauliflower (Brassica oleraceae L. var. Botrytis)

Cauliflower (Brassica oleraceae L. var. Botrytis) is a good source of bioactive compounds, such as glucosinolates, phenolic compounds and vitamins. In this study, the effects of some processes (i.e. boiling, steaming) on the sinigrin bioaccessibility as a major glucosinolate found in cruciferous vegetables after in vitro digestion, also in vitro antimutagenic activities, total phenols and total antioxidant capacities of cauliflower were determined. The sinigrin content was reduced by approximately 9.6% and 29.1% in steamed and boiled cauliflower (p > 0.05), respectively. After in vitro simulated digestion, sinigrin content was decreased by 26.4% in raw samples, increased by 29.5% and 114.7% in steamed and boiled samples, respectively. In all samples, mutagenic effect to Salmonella typhimurium TA 100 was not seen. When samples were steamed, phenol content was increased by 14.83%. After boiling total phenol content of cauliflower was decreased by 1.8%. Total antioxidant capacities (TAC) measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3 ethylbenzothiazoline-6-sulfonic acid) (ABTS) methods were increased by 47% and 39%, respectively (p < 0.05) in steamed samples and decreased by 8% and 7% with boiling, respectively (p > 0.05). TAC in raw sample of cauliflower, which was investigated in phosphomolybdenum assays, was determined as 18.7 mg ascorbic acid equivalents (AAE)/100 g. In all cases, the highest antioxidant activity was determined in the steamed samples, while the lowest antioxidant activity was in boiled samples.     

Antioxidant activity and phenolic composition of organic and conventional grapes and wines

The phenolic compounds and antioxidant activity from Monastrell variety grapes obtained by organic and conventional agriculture during the last month of ripening and the wines obtained from them were studied. Samples of grapes were collected from the last month of ripening to full maturity in each plot, and winemaking was carried out on the day of the final collection of grape samples, coinciding with the maturity of the grapes. The antioxidant activity a month before harvesting was higher in the organic grapes (5.7 ± 0.03 mM Trolox/g) than in the conventional ones (4.40 ± 0.05 mM Trolox/g), although these differences disappear in the moment of harvesting. Similarly the total amount of phenolic compounds a month before harvesting was higher in the organic grapes (974.2 ± 54.4 mg/kg) than in the conventional grapes (447.7 ± 27.8 mg/kg), although these differences disappear at the moment of harvesting. In wine, phenolic compounds and the antioxidant activity were slightly higher in organic wine than in conventional wine, although the differences were not significant.