Bioactivity and total phenolic content of 34 sour cherry cultivars

Thirty four sour cherry cultivars were investigated for their total phenolic content, total anthocyanin content, total antioxidant capacity and cancer cell proliferation inhibition activity. Birgitte × Böttermö and Fanal, which contained the highest total phenolics (754 ± 13.4 and 596 ± 5.7 mg gallic acid equivalent/100 g, respectively), displayed the strongest total antioxidant capacity (63 ± 7.5 and 52 ± 6.9 μmol trolox equivalent/g, respectively) and cancer cell proliferation inhibition activity (63 ± 1.7 and 70 ± 1.6%, respectively). Surefire and Favorit were the cultivars with lowest total phenolic content (111 ± 2.2 and 74 ± 2.5 mg gallic acid equivalent/100 g, respectively) and total anthocyanin content (40 ± 1.1 and 21 ± 0.5 malvin equivalent/g, respectively), total antioxidant capacity (12 ± 2.3 and 9 ± 3.1 μmol trolox equivalent/g, respectively) and cancer cell inhibition activity (7 ± 3.5 and 2 ± 0.2%, respectively). Multivariate data analysis on proton nuclear magnetic resonance (¹H-NMR) data showed discrimination of the cultivars according to their bioactivity. The present study suggests that combination of ¹H-NMR and multivariate statistical analysis can be used to predict and discriminate total phenolic content, total anthocyanin content, total antioxidant capacity and cancer cell proliferation inhibition activity of sour cherry cultivars.     

Antioxidants and other chemical and physical characteristics of two strawberry cultivars at different ripeness stages

The present work evaluated the quality and antioxidant characteristics of ‘Osogrande’ and ‘Camino Real’ strawberries at different ripeness stages. Strawberries (Fragaria x ananassa Duch.) were harvested, selected, graded according to ripeness (green, pink or 3/4 ripe and ripe) and evaluated for pH, total soluble solids, total titratable acidity, sugar/acid ratio, vitamin C, total phenolic compounds, total ellagic acid, total and individual anthocyanins and antioxidant activity by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP). The highest total soluble solid content was found for pink (7.5° Brix) and ripe (7.9° Brix) ‘Osogrande’ strawberries. At pink stage, this cultivar showed higher amounts of total phenolics (2909.48 mg kg⁻¹ FW) and total ellagic acid (454.16 mg kg⁻¹ FW). Pink ‘Camino Real’ strawberries presented the highest content of vitamin C (528.55 mg kg⁻¹ FW). Antioxidant activity was higher for ‘Osogrande’ cultivar, at green stage, according to DPPH (11.91 μmol BHT g⁻¹ FW) and FRAP (36.75 μmol ferrous sulphate  g⁻¹ FW) assays and at ripe stage, only for DPPH assay (12.83 μmol BHT g⁻¹ FW). Anthocyanins increased along ripening, with more elevated concentrations in ripe ‘Camino Real’ strawberries (292.9 mg kg⁻¹ FW). Cyanindin-3-glucoside showed a higher concentration for the same treatment (17.23 mg kg⁻¹ FW), which might contribute to a more redish color. Although ripe berries have a better flavor and are more appreciated, higher antioxidant contents and activities were observed at pink stage in which higher amounts of total phenolics, total ellagic acid and vitamin C were noticed for both cultivars.     

Bioactive compound composition of pomegranate fruits removed during thinning

Thinning consists of reducing fruit load at immature stage and thus allowing remaining fruits to develop to their maximum size and quality. The waste material produced during this farming practice was characterised in 9 pomegranate cultivars, by evaluating: weight, size, maturity index, pH, organic acids and sugars profiles, contents of minerals, punicalagin, and ellagic acid, total polyphenols and antioxidant activity. Citric and quinic were the main organic acids. Potassium was the predominant mineral, reaching up to 11 g kg⁻¹ dry weight (dw). Total polyphenol content ranged from 777 to 1660 g GAE kg⁻¹ dw, α-punicalagin from 101 to 195 and β-punicalagin from 80.1 to 111 g kg⁻¹ dw. The antioxidant activity was assessed by three methods and its values varied from 2923 to 4486 for ABTS, from 3153 to 4685 for FRAP, and from 2075 to 2934 mmol Trolox kg⁻¹ dw for DPPH. Pomegranate thinning fruits, especially sour-sweet cultivars, are rich in bioactive compounds, with a potential use in the food, chemical and pharmaceutical industries.     

Phytonutrient content of Solanum sisymbriifolium Lam. berries

Solanum sisymbriifolium Lam. (Litchi tomato) is grown ornamentally, and in Europe it is used as a trap crop for management of the potato cyst nematode (PCN). Its berries are edible, but little is known about their nutritional content. If more was known about their nutritional value this could provide incentive to grow it as a food crop. Phytonutrient content was characterized in berries from four varieties and four synthetic breeding lines developed to have reduced spininess. Litchi tomatoes contained 6.8–10.4 mg of total phenolics per g dry weight. Antioxidants measured by FRAP ranged from 148 to 242 μmol TE/g DW. HPLC analysis showed chlorogenic acid (1856–4385 μg/g DW) was the most abundant phenylpropanoid. Ascorbic acid ranged from 2042 to 4511 μg/g DW. The yellow/orange flesh color was due to carotenoids, with β-carotene the most abundant (204–633 μg/g DW). Soluble protein in Litchi tomato ranged from 86.9 to 120.9 mg/g. Of the cultivated Litchi tomato varieties analyzed, SS91 had the highest amount of antioxidant activity, ascorbic acid, chlorogenic acid and β-carotene. These results suggest that Litchi tomato fruits can be a good source of phytonutrients, expanding the plant's functionality beyond its use as a PCN trap crop.     

The effect of traditional stir-frying process on hydrophilic and lipophilic antioxidant capacities of pine nut kernels

Abstract

The effect of traditional stir-frying process at different heating temperatures (50–150?°C) and time periods (5–20?min) on hydrophilic part (total and individual phenolics), lipophilic part (tocopherol and phytosterol compounds) and their corresponding antioxidant capacities in pine nut kernels were investigated. The concentrations of total phenolics, phenolic acids, tocopherols and phytosterols in raw pine nut kernels were 15.76?mg gallic acid equivalents/100?g dry weight (mg GAE/100?g DW), 12.15?mg/100?g DW, 28.67?mg/100?g DW and 198.81?mg/100?g DW, respectively. Stir-frying at low temperatures over short time periods led to an increase of phenolics, phytosterols and hydrophiliic antioxidant capacities. However, these values decreased under the longer heating time and the higher temperature. Tocopherols and lipophilic antioxidant capacities did not show clear changes at lower heating temperatures or shorter heating times, while they had an apparent decreasing trend at higher heating temperatures or longer heating times. Gallic acid might be the main component, which is responsible for the hydrophilic antioxidant capacity (R^2?=?0.84, 0.81 and 0.81 using DPPH, FRAP and H-ORAC assays), and tocopherols might be the main antioxidant components in the lipophilic part (R^2?=?0.87 and 0.89 using DPPH and L-ORAC assays).     

An investigation of the antioxidant properties and colour of glasshouse grown tomatoes

The colour and the antioxidant content of five different cultivars of tomatoes (Lycopersicon esculentum L.), grown in glasshouses using commercial hydroponic techniques, were measured in freshly harvested tomatoes and after 2 and 5 days of storage in the dark at 15°C. The two cocktail cultivars of tomatoes, Aranca and Flavourine, were the smallest tomatoes but they contained higher dry matter contents compared with the three standard salad cultivars, Excell, Celero and Dutch Chaser. There were significant differences (P<0.001) in lycopene (the major carotenoid), ascorbic acid and total antioxidant activity in the whole fruit of the five different cultivars evaluated at harvest, while the total phenolic contents were very similar. The lycopene levels of all the cultivars increased significantly (P<0.001) after storage for 2 and 5 days at 15°C. Overall, the total phenolic content of all the cultivars did not change appreciably after storage at 15°C while the levels of ascorbic acid fell by 12.6% when stored for 5 days in the dark. There was a significant difference (P<0.001) in the total antioxidant activity between the five different cultivars when freshly harvested; the highest levels of total antioxidant activity were observed in the two cocktail cultivars, Aranca and Flavourine. Antioxidant activity showed different patterns of change depending on cultivar. An increase in the total antioxidant values could be seen in cultivars Dutch chaser and Excell, after storage for 5 days at 15°C. The total antioxidant activity values of Flavourine and Celero fell on storage while the values for stored Aranca were very similar to the values when freshly harvested.

The skin colour, as shown by Commission Internationale l'Eclairage (CIE) L*a*b* values of each cultivar were markedly different at harvest even though each cultivar was harvested at the same maturity. The a* value of each cultivar increased significantly (P<0.001) when they were stored in the dark, for either 2 or 5 days, at 15°C. Regression analysis showed that overall there was no significant relationship (R²=0.14) between the lycopene content and the a* value of all the tomatoes; however, when examined individually, the two cocktail tomatoes Aranca and Flavourine showed strong correlation—R²=0.96 and R²=0.97, respectively. Overall, the (a*/b*)² was the most reliable indicator of lycopene concentration (R²=0.96) in the tomatoes examined in this study.     

Application of principal component and hierarchical cluster analysis to classify fruits and vegetables commonly consumed in Ireland based on in vitro antioxidant activity

The purpose of this study was to gain insights into the variations in antioxidant profiles between fruits and vegetables using pattern recognition tools; classification was achieved based on global antioxidant activity, levels of antioxidant groups (total phenolics, total anthocyanins, ascorbic acid) and quality parameters (instrumental colour, moisture). Six vegetables (broccoli, carrot [organic and intensively grown], butterhead lettuce, red onion, yellow onion) and eight fruits (blueberries, cherry tomato, cranberries, red grapes, green pepper, raspberry, red pepper and strawberry) commonly consumed in Ireland were analysed. Antioxidant activity (ARP) and concentrations of bioactive compound groups differed according to sample type. Berry fruits had the highest antioxidant activity (1.51-2.97 (g/L)⁻¹). By contrast, vegetables were quite low in antioxidant activity (0.14-0.39 (g/L)⁻¹). Interrelationships between the parameters analysed and the different fruits and vegetables were investigated by principal component analysis (PCA) and hierarchical cluster analysis (HCA). PCA revealed that the first two components represented 62% of the total variability in antioxidant activity and different antioxidant groups. HCA classified samples into four main groups on the basis of the measured parameters.     

Concentration of vitamin D2 in white button mushrooms (Agaricus bisporus) exposed to pulsed UV light

Enrichment of vitamin D₂ in Agaricus bisporus white button mushroom (WBM) using continuous UV light needs a longer exposure time, which can lead to discoloration. Using a Xenon pulsed UV light source, the yield of vitamin D₂ was evaluated in freshly harvested button mushrooms and mushroom slices after exposure to 2.5, 3, 6 and 9 pulses of UV light at an average dose of 1.150 J/cm² energy per pulse. Increase in vitamin D₂ content was proportionate to the number of pulses of UV light. There was no difference in the vitamin D₂ content of mushrooms between 200 g and 500 g punnets for the corresponding number of pulses (737 ± 81, 847 ± 38, 1148 ± 182, 1611 ± 444% versus 747 ± 48, 911 ± 35, 1307 ± 109, 2028 ± 181% Daily Value/serving, respectively; P > 0.05). Mushrooms in the top layer showed significantly higher amounts of vitamin D₂ content than those in the bottom layer of a 500 g punnet (657 ± 22, 796 ± 76, 1433 ± 138, 1878 ± 178% versus 129 ± 60, 237 ± 117, 403 ± 35, 830 ± 257% DV/serving, respectively; P < 0.01). A single layer of sliced mushrooms (∼5 mm thick) showed higher amounts of vitamin D₂ content than sliced mushrooms packaged together after pulsed UV light exposure (7882 ± 1074, 6867 ± 944, 10,826 ± 472, 13,001 ± 1635% versus 1221 ± 281, 1293 ± 210, 1598 ± 207, 2018 ± 459% DV/serving, respectively; P < 0.001). Discoloration of whole or sliced mushrooms was not observed. Thus, pulsed UV light provides a highly effective method for increasing vitamin D₂ levels in A. bisporus white button mushroom.     

Influence of extrusion on the bioactive compounds and the antioxidant capacity of the bean/corn mixtures

The aim of this investigation was to examine the influence of extrusion on the bioactive compounds and the antioxidant capacity of bean/corn mixtures. Whole bean flour and nixtamalized corn were mixed in a 60:40 proportion and extrusion was performed in different moisture (14.5%, 15.4%, 17.1% and 18.0%) and temperature (150°C, 160°C, 170°C, 180°C and 190°C) conditions in order to find the optimal extrusion conditions. According to their functional properties and antioxidant status, the mixtures 142°C/16.3% H, 170°C/16.3% H and 198°C/16.3% H were defined as optimal, moderate and bad, respectively. Total polyphenols and flavonoids in the mixture of 142°C/16.3% H (15.09±1.7 mg gallic acid equivalent [GAE]/g dry weight [DW] and 1.57±0.2 mg catechin equivalent [CE]/g DW) were significantly higher (P<0.05) than in the sample 170°C/16.3% H (9.42±1.1 mg GAE/g DW and 1.4±0.1 mg CE/g DW) and the mixture 198°C/16.3% H (6.46±0.8 mg GAE/g DW and 0.78±0.1 mg CE/g DW). The antioxidant activity (37.02±3.8 and 25.01±2.5 μM Trolox equivalent [TE]/g DW) of mixture 142°C/16.3% H, determined by the cupric reducing antioxidant capacity with Trolox equivalent antioxidant capacity and β-carotene-linoleic acid (β-carotene,% of inhibition) assays, was significantly higher (P<0.05) than in 170°C/16.3% H (25.69±2.8 and 17.02±1.8 μM TE/g DW) and in mixture 198°C/16.3% H (13.93±1.5 and 8.94±0.9 μM TE/g DW), respectively. The free polyphenols, flavonoids and the antioxidant activities showed lower results than the hydrolyzed ones. The correlation coefficients between polyphenols, flavonoids, and cupric reducing antioxidant capacity capacities were between 0.93 and 0.99. In cereal proteins extracted and separated by electrophoresis, some differences were found in the sodium dodecyl sulfate-protein bands in the region from 36 to 45 kDa for 142°C/16.3% H, in comparison with other samples. Therefore, there is a need to find such conditions for the extrusion procedures that would take into consideration the contents of the bioactive compounds and the antioxidant capacity in the end product.     

Influence of extrusion on the bioactive compounds and the antioxidant capacity of the bean/corn mixtures

The aim of this investigation was to examine the influence of extrusion on the bioactive compounds and the antioxidant capacity of bean/corn mixtures. Whole bean flour and nixtamalized corn were mixed in a 60:40 proportion and extrusion was performed in different moisture (14.5%, 15.4%, 17.1% and 18.0%) and temperature (150°C, 160°C, 170°C, 180°C and 190°C) conditions in order to find the optimal extrusion conditions. According to their functional properties and antioxidant status, the mixtures 142°C/16.3% H, 170°C/16.3% H and 198°C/16.3% H were defined as optimal, moderate and bad, respectively. Total polyphenols and flavonoids in the mixture of 142°C/16.3% H (15.09±1.7 mg gallic acid equivalent [GAE]/g dry weight [DW] and 1.57±0.2 mg catechin equivalent [CE]/g DW) were significantly higher (P<0.05) than in the sample 170°C/16.3% H (9.42±1.1 mg GAE/g DW and 1.4±0.1 mg CE/g DW) and the mixture 198°C/16.3% H (6.46±0.8 mg GAE/g DW and 0.78±0.1 mg CE/g DW). The antioxidant activity (37.02±3.8 and 25.01±2.5 µM Trolox equivalent [TE]/g DW) of mixture 142°C/16.3% H, determined by the cupric reducing antioxidant capacity with Trolox equivalent antioxidant capacity and β-carotene–linoleic acid (β-carotene,% of inhibition) assays, was significantly higher (P<0.05) than in 170°C/16.3% H (25.69±2.8 and 17.02±1.8 µM TE/g DW) and in mixture 198°C/16.3% H (13.93±1.5 and 8.94±0.9 µM TE/g DW), respectively. The free polyphenols, flavonoids and the antioxidant activities showed lower results than the hydrolyzed ones. The correlation coefficients between polyphenols, flavonoids, and cupric reducing antioxidant capacity capacities were between 0.93 and 0.99.

In cereal proteins extracted and separated by electrophoresis, some differences were found in the sodium dodecyl sulfate–protein bands in the region from 36 to 45 kDa for 142°C/16.3% H, in comparison with other samples. Therefore, there is a need to find such conditions for the extrusion procedures that would take into consideration the contents of the bioactive compounds and the antioxidant capacity in the end product.     

Food intake, postprandial glucose, insulin and subjective satiety responses to three different bread-based test meals

The effect of bread consumption on overall food intake is poorly understood. The aim of this study was to measure postprandial food intake after a set breakfast containing three different breads. Ten males and 10 females aged 20.1–44.8 years, BMI 18.4–24.8 kg/m², consumed two slices of White Bread, Bürgen^® Wholemeal and Seeds Bread or Lupin Bread (all 1300 kJ) with 10 g margarine and 30 g strawberry jam. Fullness and hunger responses and were measured before and during the test breakfasts. Glucose and insulin responses (incremental area under each two-hour curve (iAUC)) were calculated. Food intake was measured and energy and nutrient intake determined at a buffet meal two hours later. Subjects consumed significantly less energy after the Bürgen^® Bread meal compared to the White Bread meal (2548 ± 218 vs. 3040 ± 328 kJ, Bürgen^® Bread vs. White Bread, P < 0.05). There were higher fullness responses for the Lupin Bread (P < 0.01), and the Bürgen^® Bread (P < 0.05) compared with the White Bread. Lupin Bread and Bürgen^® Bread produced smaller postprandial glucose responses (79 ± 7, 74 ± 4, 120 ± 10 mmol/L min iAUC, Lupin, Bürgen^® and White Bread respectively, P < 0.01). Differences in insulin responses were also observed (6145 ± 1048, 6471 ± 976, 9674 ± 1431 pmol/L min iAUC, Lupin, Bürgen^® and White Bread respectively, P < 0.01). Equal-energy portions of three different commercially available breads differed in their short-term satiation capacity. Further studies are needed to demonstrate any potential benefit for weight management.     

Phenolic composition and antioxidant capacity of bacaba-de-leque (Oenocarpus distichus Mart.) genotypes

Phenolic compound composition and antioxidant capacity of four Oenocarpus distichus Mart. (bacaba-de-leque) genotypes were determined. In order to set the parameters for phenolic compound extraction, the effect of methanol concentration and extraction time on the reducing power of the extracts was evaluated using the surface response methodology. The optimal conditions were: a 60:40 methanol:water (v/v) solution and 11 min of extraction. Extracts were analyzed by ultra-high performance liquid chromatography with diode array detection and by ultra-high performance liquid chromatography coupled to mass spectrometry. Eleven substances were identified, of which six were quantified. Rutin was the major compound in bacaba-de-leque genotypes (15.2–56.8 μg.g⁻¹) followed by epicatechin (15.5–21.2 μg.g⁻¹). The Black-03 genotype had the highest amounts of all phenolic compounds and the highest antioxidant capacity by DPPH and ORAC assays, indicating that this genotype may be selected in breeding programs to obtain cultivars with higher phenolic compound contents and antioxidant capacity. Moreover, the results indicated that bacaba-de-leque has great potential as a novel supplier of phenolic acids and flavonoids to human diet, with levels comparable to or higher than other fruits belonging to the same family, such as açaí.     

Texture, not flavor, determines expected satiation of dairy products

Consumers’ expectations about the satiating capacity of a food may differ markedly across a broad range of food products, but also between foods within one product category. Our objective is to investigate the role of sensory attributes and means of consumption in the expected satiation of dairy products. In three independent experiments we measured the expected satiation of (1) commercially available yogurts and custards (29 adults, age: 26 ± 5 y, BMI: 22.9 ± 2.4 kg/m²); (2) lemon- and meringue-flavored custards with different textures (30 adults, age: 23 ± 4 y, BMI: 22.1 ± 2.1 kg/m²); and (3) chocolate milk and chocolate custard consumed with either a straw or a spoon (30 adults, age: 20 ± 2.2 y, BMI: 21.5 ± 2.2 kg/m²); all based on a single mouthful. Expected satiation was linked to the product's perceived characteristics. We observed an effect of texture (p < 0.0001), but not of flavor on expected satiation (p = 0.98) in Experiment 2; and an effect of texture (p < 0.0001), but not of means of consumption on expected satiation (p = 0.63) in Experiment 3. Thickness was positively correlated with expected satiation in Experiment 1 (r = 0.45; p < 0.001) and Experiment 2 (r = 0.54; p < 0.001). Expected satiation of dairy products increased consistently with increasing thickness; flavor characteristics or means of consumption as tested did not change expected satiation effects.     

Chemotype and genotype combined analysis applied to tomato (Lycopersicon esculentum Mill.) analytical traceability

A large number of fresh fruits and vegetables are primary sources of antioxidants; tomato (Lycopersicon esculentum Mill.) is accepted worldwide as a significant source of antioxidant functional compounds (vitamin C, lycopene, rutin). Many cultivars and hybrids of tomato, having different chemical and nutritional characteristics, are available on the market. Tomato cultivars for industrial processing are very different, not only in fruit characteristics (size, shape), but also in lycopene and antioxidant contents. The aim of this study was the chemotyping and genotyping of the tomato varieties Heinz 3402, Leader and Perfectpeel, (1) to evaluate the genetic traceability of these varieties, and (2) to determine whether their functional antioxidants compounds are useful markers of traceability. Principal component analysis (PCA) was first applied to the Random Polymorphic DNA (RAPD) fingerprints, confirming that this approach is a powerful identification method at intra-specific level. Heinz 3402 showed the highest antioxidant activity, followed by Perfectpeel and Leader varieties. Perfectpeel showed the lower lycopene content, while Leader and Heinz 3402 showed significantly higher values (13.68 and 15.78 mg/100 g, fresh weight, respectively). The highest rutin content was observed in Heinz 3402 (12.46 ± 0.69, mg/100 g, fresh weight), followed by Leader (7.87 ± 0.72) and Perfectpeel (2.70 ± 0.68). Antioxidant capacity was significantly correlated with the lycopene and rutin content. Finally, PCA was applied to chemotype data-sets, confirming both mineral content and functional antioxidant compounds as useful markers to unambiguously identify these high-lycopene content varieties.     

Influence of storage and in vitro gastrointestinal digestion on total antioxidant capacity of fruit beverages

Eight fruit beverages containing grape, orange and apricot, with/without iron and/or zinc and with/without milk added were analyzed for total antioxidant capacity (ORAC and TEAC methods), ascorbic acid content, and total polyphenols. The influence of cold storage (2-4 °C) during the product shelf-life (135 days) and antioxidant capacity after an in vitro gastrointestinal digestion were evaluated. Antioxidant capacity for all beverages together increased significantly (p < 0.05) at the end of storage (16.4% and 12.8% for ORAC and TEAC, respectively), whereas ascorbic acid remained stable. Regarding in vitro digestion, antioxidant values of bioaccessible fractions of fruit beverages increased (p < 0.05) 59% and 20% for ORAC and TEAC, respectively, while ascorbic acid and polyphenol content fell 36% and 16%, respectively (p < 0.05). Supplementation of fruit beverages with milk and/or Fe/Zn did not modify total antioxidant capacity of samples during either cold storage or during in vitro digestion.     

Minerals and trace elements in a collection of wheat landraces from the Canary Islands

Phosphorous, Na, K, Ca, Mg, Fe, Cu, Zn, Mn and Se were determined in eighteen wheat landraces from Canary Islands and a commercial cultivar. The mean values obtained were: P (2370 ± 333 mg/kg); Na (102 ± 52 mg/kg); K (4363 ± 386 mg/kg); Ca (351 ± 62 mg/kg); Mg (1163 ± 155 mg/kg); Fe (40.0 ± 5.5 mg/kg); Cu (2.68 ± 0.93 mg/kg); Zn (32.1 ± 2.9 mg/kg); Mn (22.1 ± 3.5 mg/kg); Se (67.7 ± 40.4 μg/kg). There were differences (P < 0.05) in the mineral and trace element between the analyzed cultivars, and between the species and subspecies of wheats. Therefore, the Triticum aestivum species had higher mean P, Mg, Fe, Cu, Zn and Mn concentrations, and a lower mean Se concentration, than Triticum turgidum species. The environment and agronomic practices could affect the genetic information of the seeds determining changes in the mineral and trace element composition. The wheat represents an excellent source of Mn (over 100% of recommended dietary intake, RDI), as well as P, Mg, Fe, Cu, Zn and Se (20–50% of RDI). Many correlations were found between the parameters analyzed emphasizing the Cu–Mg (r = 0.691) and Cu–Mn (r = 0.619) correlations. Linear discriminant analysis allowed a good differentiation of the wheat samples according to the cultivar (89.7% of wheat samples classified correctly).     

Antioxidant compounds and antioxidant activity in acerola (Malpighia emarginata DC.) fruits and derivatives

Acerola (Malpighia emarginata DC.) is a wild plant from Central America. This fruit is well known as an excellent food source of vitamin C, and it also contains phytochemicals such as carotenoids and polyphenols. The present work evaluates the antioxidant capacity of hydrophilic extracts of acerola pulps and juices by 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), ORAC and 1,1-diphenyl-2-picrylhydrazyl (DPPH) methods. Antioxidant activity values obtained for acerola juice were higher than those reported for other fruit juices particularly rich in polyphenols such as strawberry, grape and apple juices, among others. Vitamin C, total phenol index (TPI), total anthocyanins and polyphenolic compounds by high performance liquid chromatography (HPLC), as main factors responsible for antioxidant activity, were determined. Contents in total ascorbic acid ranged from 6.32 to 9.20 g kg⁻¹ of pulp and 9.44 to 17.97 g L⁻¹ of juice. Five different polyphenolic compounds were identified in the samples by means of HPLC and diode-array detection: chlorogenic acid, (−)-epigallocatechin gallate, (−)-epicatechin, procyanidin B1 and rutin, being the two last predominant. By means of solid phase extraction (SPE) three soluble polyphenolic fractions (phenolic acids, anthocyanins and flavonoids) were separated from the different sample extracts, and their respective antioxidant activities calculated. Among them, phenolic acids are the main contributors to the antioxidant activity.     

Comparative study of the nutritional and bioactive compounds content of four walnut (Juglans regia L.) cultivars

The proximate and mineral composition, fatty acid profile, total polyphenol, melatonin and serotonin contents were assessed in four walnut (Juglans regia L.) cultivars (cv. Serr, Hartley, Chandler and Howard). The aim was to decide which cultivar is the most suitable from a nutritive, but also commercial, point of view. Proteins and fats accounted for more than 70% of the walnut kernel weight. Due to their content in bioactive compounds such as melatonin, serotonin and total phenols, their high content in magnesium (up to 443 mg 100 g⁻¹ FW) and other minerals, their high contents in polyunsaturated fatty acids (up to 78.0% of total fatty acids) and their favorable n−6/n−3 ratio, among other healthful properties, consumption of all the studied cultivars would be potentially beneficial to health. According to its fatty acid profile, Howard would be the most healthful cultivar, but also it would be theoretically the most sensitive to rancidity, and thus the cultivar with the shortest shelf life. Nonetheless, this cultivar showed the highest content in the antioxidants melatonin and total polyphenols.     

The effect of milk fermented by yogurt cultures plus <Emphasis Type="Italic">Lactobacillus casei</Emphasis> DN-114001 on the immune response of subjects under academic examination stress

Summary Background A suppressed immune response has been documented in students under examination stress. Aims The current study aimed to evaluate the effect of milk fermented with yogurt cultures plus Lactobacillus casei DN-114001 (Actimel^®) on the immune system of subjects under academic examination stress. Methods University students were allocated to one of two groups, receiving during 6 weeks (3 weeks prior to, as well as the 3-week duration of the examination period) either: a) a glass of semi-skimmed milk each day (control group, n=63) or b) two 100mL portions per day of fermented milk (treatment group, n=73). Anxiety and immunological measurements were monitored at baseline (Phase 0) and study end (Phase 1). Results The results were expressed as the differences between the data obtained from Phase 0 and Phase 1. This was calculated by subtracting Phase 1 results from the Phase 0 and it is denominated Treatment effect. Mean (± SE) anxiety increased significantly (P<0.05) over the 6-week study in all students, from 40.74±2.50 to 61.19±2.64 (in percentiles). There was no significant treatment effect since this increase was similar in the control and the treatment groups (21.65±5.09 vs 19.14±3.67, respectively). However, there was a significant treatment effect (P<0.05) on the mean change in absolute number of lymphocytes during the 6-week study, which decreased in the control group (–0.04±0.12 cells x 103/mm³) and increased in the treatment group (0.37±0.11 cells x 103/mm³). There was also a significant treatment effect (P<0.05) on the change in absolute numbers of CD56 cells during the 6-week study. Mean absolute CD56 cells significantly decreased (P<0.05) in the control group (–51.97±21.33 cells/mm³),while remaining similar in the treatment group (17.29±17.27 cells/mm³). During the study, mean serum cortisol increased 4.30±0.98 µg/dL in the control group, and 1.75±1.05 µg/dL in the treatment group and no significant differences were found between both values (P=0.062). Conclusions Milk fermented with yogurt cultures plus Lactobacillus casei DN-114001 was able to modulate the number of lymphocytes and CD56 cells in subjects under academic examination stress.     

Profile of polyphenols and phenolic acids in bracts and receptacles of globe artichoke (Cynara cardunculus var. scolymus) germplasm

The aim of this work was to assess and quantify polyphenols and hydroxycinnamic acids in different parts of the heads of 6 globe artichoke cultivars by HPLC-DAD-MS/MS. Globe artichoke (Cynara cardunculus var. scolymus) has been used in folk medicine since Roman times, possibly because of high hydroxycinnamic acid and flavone levels. However, to our knowledge, little is known about how these compounds are distributed in different parts of the artichoke head (outer bracts, inner bracts and receptacle). The phenolic profile was significantly different between cultivars and in different parts of the head, suggesting that individual compounds are accumulated preferentially in specific head parts and cultivars. In particular, the phenolic profile of the outer bracts exhibits very low (443 mg kg⁻¹ dry matter) or zero hydroxycinnamic acid content, and these compounds are present mainly in the receptacle (the edible part; mean value, 1473 mg kg⁻¹ dry matter). This study presents data that indicate the different levels of phenolics in different parts of artichoke, and shows the potential of various artichoke parts as a source of different levels of dietary phenolics.