Antioxidant capacity of the Spanish Mediterranean diet

The objective of this work was to determine the total dietary antioxidant capacity (TDAC) of the Spanish Mediterranean diet. The antioxidant capacity of plant foods and beverages included in National food consumption data was determined. TDAC of the Spanish diet was estimated at 6014 and 3549 μmol trolox equivalents by FRAP (ferric reducing antioxidant power) and ABTS (free radical-scavenging capacity) procedures, respectively. About 68% of TDAC came from beverages and 20% from fruits and vegetables, with a very low contribution from cereals. The capacity to inhibit in vitro LDL oxidation of plant foods and beverages was consistent with their antioxidant capacity. The recommended daily intakes of antioxidant vitamins, C and E, represent about 10% of TDAC. Total phenolics intake was estimated as 1171 mg gallic acid/person/day by the Folin–Ciocalteau method. TDAC may be a parameter to be considered in nutritional and epidemiological studies.     

Preliminary characterisation of cornelian cherry (Cornusmas L.) genotypes for their physico-chemical properties

Fruit weight, antioxidant capacity, total anthocyanins, total phenolics, ascorbic acid, soluble solid content (SSC), reducing sugar and acidity of a number of selected cornelian cherry (Cornusmas L.) genotypes of varied pigmentation were investigated. Two methods, namely β-carotene bleaching and ferric reducing antioxidant power (FRAP) were used to determine total antioxidant capacity, while Folin–Ciocalteu reagent was used to determine total phenols. Fruit weight, SSC and ascorbic acid content of genotypes were 2.09–9.17; 12.53–21.17% and 29–112 mg/100 g, respectively. Antioxidant activity and total phenolic content varied among genotypes and 44-18 genotype had the highest antioxidant capacity using both methods. This genotype also had the highest total phenolic (74.8 mg GAE/g DW) and total anthocyanin (115 mg cyanidin-3-glucoside equivalents /100 g FW) content. There are linear relationships between antioxidant capacities and total phenols. The present study demonstrates the potential of certain cornelian cherry genotypes, notably 44-18, for improvement of nutritional value through germplasm enhancement programmes.     

Total antioxidant activity in 35 Ugandan fruits and vegetables

The objective of this study was to analyse antioxidant activity (AA) in fruits and vegetables from Uganda and to investigate whether AA in traditional food is sufficiently high to prevent oxidative stress and thus combat disease. We used the FRAP (ferric reducing ability of plasma) procedure. The results showed great variation in AA, ranging from 72.3 ± 13.5 (Syzygium cuminii seed) to 0.09 ± 0.05 (Cucurbita maxima fruit) mmol/100 g fresh weight (FW). We estimated serving sizes and determined the total antioxidant capacity (TDAC) per day of three traditional Ugandan diets. The dietary plants with highest AA per serving size were pomegranate (Punica granatum), Canarium schweinfurthii, guava (Psidium guajava), mango (Mangifera indica) and tree tomato (Cyphomandra betacea) with values ranging from 8.91 to 3.00 mmol/serving. Of the traditional diets, the central/eastern (C/E) and the western (W) diets had almost the same AA (9.31–9.78 and 9.75 mmol/day), while the northern (N) diet had an AA of 7.50–8.02 mmol/day.     

Antioxidant capacity and anthocyanin profile of sour cherry (Prunus cerasus L.) juice

The antioxidant capacities, total polyphenolic content and monomeric anthocyanin content of eleven types of sour cherry juice obtained from different varieties of sour cherries were investigated. Antioxidant capacity, total polyphenolic content and monomeric anthocyanin contents of the juices were within the ranges 20.0–37.9 mmol/L, 1510–2550 and 350.0–633.5 mg/L, respectively. The main anthocyanin compound in sour cherry juice was cyanidin-3-glucosylrutinoside at concentrations between 140.3 and 320.9 mg/L. Cyanidin-3-glucosylrutinoside was followed by cyanidin-3-rutinoside within a concentration range of 25.5–85.5 mg/L. Cyanidin-3-sophoroside and cyanidin-3-glucoside contents were relatively low (2.6–21.5 and 2.0–9.9 mg/L). Anthocyanin capacity and total polyphenol content were fairly well correlated (r = 0.742, p < 0.01), whereas the correlation between antioxidant capacity and monomeric anthocyanin content was insignificant (r = 0.423, p > 0.05). The correlation between antioxidant capacity – cya-3-glucosylrutinoside (r = 0.606, p < 0.01) and antioxidant capacity – cya-3-rutinoside (r = 0.628, p < 0.01) was significant.     

Total and dialyzable levels of manganese from duplicate meals and influence of other nutrients: Estimation of daily dietary intake

Both total and dialyzable Mn levels were determined in 108 duplicate meals during 36 consecutive days. Both mineral fractions were measured by a graphite furnace atomic absorption spectrometry (GFAAS) method previously optimized. A total mean Mn fraction of 1.03 ± 0.49 mg was found in the meals. The Mn supplied by the meals is directly and significantly (p < 0.001) correlated with macronutrient content (carbohydrates, fibre and protein). The mean Mn fraction dialyzed through the dialysis membrane was 0.23 ± 0.17 mg (22.0 ± 8.93% as bioaccessible fraction). The total and dialyzable Mn fractions found for breakfasts were significantly lower (p < 0.001). Nevertheless, the Mn bioavailabilities expressed as the percentage of dialyzable element, were not significantly different among the three primary meals (breakfast, lunch and dinner). A significant correlation between the total and the dialyzable fraction of Mn in meals was found (p < 0.001, r = 0.78, r² = 0.61). The dialyzed element fractions present in meals were significantly correlated mainly with carbohydrates, protein and several amino acid levels (p < 0.01). Foods with higher carbohydrate and therefore energy contents, e.g. cereals, legumes, vegetables and fruits, would be primary sources of bioaccessible Mn in the diet. The bioaccessibility of Mn was only significant influenced by energy, carbohydrates and Se levels present in meals. The mean Mn daily dietary intake (DDI) was 3.05 ± 0.61 mg day⁻¹.     

Compositional and functional characteristics of dates,syrups, and their by-products

Three native sun-dried date varieties from Oman (namely Mabseeli, Um-sellah, and Shahal), as well as their syrups and by-products (press cake and seed) were examined for their proximate composition, dietary fibre, total phenolics, and total antioxidant activity. Carbohydrate was the predominant component in all date varieties, syrups, and their by-products, followed by moisture, along with small amounts of protein, fat, and ash. Press cakes had the highest protein content, ranging in concentration from 3.62 g/100 g in Shahal to 5.23 g/100 g in Mabseeli, whereas fat was the highest in seeds and ranged from 5.02 g/100 g in Mabseeli to 5.90 g/100 g in Um-sellah. Seeds and press cakes were found to be good sources of dietary fibre, varied between 77.75 and 80.15 g/100 g fresh weight and between 25.39 and 33.81 g/100 g fresh weight, respectively. Among dates, syrups, and their by-products, seeds had the highest contents of total phenolics (3102–4430 mg of gallic acid equivalents/100 g fresh weight) and antioxidant activity (580–929 μmol of Trolox equivalents/g fresh weight). The results obtained suggest that date by-products (particularly seeds) serve as a good source of natural antioxidants and could potentially be considered as a functional food or functional food ingredient.     

Calcium,iron, zinc and copper transport and uptake by Caco-2 cells in school meals: Influence of protein and mineral interactions

A combined in vitro digestion/Caco-2 cell culture system is used to estimate calcium, iron, zinc and copper transported and cell uptake (retention plus transport) corresponding to 8 dishes usually distributed to a Spanish school lunchroom, with an evaluation of the influence of proteins and mineral interactions. Mineral uptake percentages were as follows: Ca (3.3–56.3), Fe (7.8–67.4), Zn (5.6–54.9), Cu (14.6–96.6). The protein content of the menus analyzed (22.9–162.9 mg/g) exerts a positive influence upon iron uptake (r = 0.938), and a negative influence upon calcium uptake (r = −0.755) – with no influence upon the uptakes of either Zn or Cu. Mineral interactions are observed at dietary concentrations in the school menus studied. A negative and positive interaction is seen between soluble iron after in vitro digestion and Zn transported (r = −0.733) and Cu retention (r = 0.800), respectively. Solubilized Zn exerts a negative influence upon iron retained (r = −0.831).     

Total phenolics,ascorbic acid,and antioxidant capacity of noni (Morinda citrifolia L.) juice and powder as affected by illumination during storage

Total phenolics, ascorbic acid, and antioxidant capacity of noni (Morinda citrifolia L.) juice and powder were determined during storage at 24 °C. After 2 weeks of storage, illuminated noni juice lost 32% of total phenolics, 89% of ascorbic acid, and 46–65% of antioxidant capacity—about 8%, 22%, and 9–15% more than unilluminated juice. Both illuminated and unilluminated juice lost 97% of ascorbic acid by 4 weeks. The difference in antioxidant characteristics between illuminated and unilluminated juice became insignificant at 12 weeks. After 12 weeks, illuminated noni powder lost 21% of total phenolics, 17% of ascorbic acid, and 23–36% of antioxidant capacity—about 13%, 4%, and 7–19% more than the unilluminated powder. Noni powder in brown bottles retained antioxidant characteristics significantly greater than that in clear bottles. Protection from light effectively reduced degradation of antioxidant characteristics of noni juice for only 2 weeks but those of noni powder for at least 3 months.     

Quality characteristics of biscuits prepared from finger millet seed coat based composite flour

Finger millet seed coat is an edible material and contains good proportion of dietary fibre, minerals and phytochemicals. The seed coat matter (SCM) forms a by-product of millet milling, malting and decortication industries and can be utilised as composite flour in biscuit preparation. The SCM from native, malted and hydrothermally treated millet contained 9.5–12% protein, 2.6–3.7% fat and 40–48% dietary fibre, besides 3–5% polyphenols and 700–860 mg/100 g of calcium. The biscuits prepared using the composite flour were of crisp texture and exhibited breaking strength of 1480–1690 g compared to control biscuits (1560 g). The biscuits were of mild grey colour (ΔE = 40–50) and exhibited higher protein, dietary fibre and calcium contents. The sensory evaluation of the biscuits indicated that 10% of SCM from native and hydrothermally processed millet and 20% from malted millet could be used in composite biscuit flour.     

Optimisation of accelerated solvent extraction of antioxidant compounds from rosemary (Rosmarinus officinalis L.), marjoram (Origanum majorana L.) and oregano (Origanum vulgare L.) using response surface methodology

The present study optimised the accelerated solvent extraction (ASE) conditions (Dionex ASE® 200, USA) to maximise the antioxidant capacity of the extracts from three spices of Lamiaceae family; rosemary, oregano and marjoram. Optimised conditions with regard to extraction temperature (66–129 °C) and solvent concentration (32–88% methanol) were identified using response surface methodology (RSM). For all three spices results showed that 129 °C was the optimum temperature in order to obtain extracts with high antioxidant activity. Optimal methanol concentrations with respect to the antioxidant activity of rosemary and marjoram extracts were 56% and 57% respectively. Oregano showed a different response to the effect of methanol concentration and was optimally extracted at 33%. The antioxidant activity yields of the optimal ASE extracts were significantly (p < 0.05) higher than solid/liquid extracts. The predicted models were highly significant (p < 0.05) for both total phenol (TP) and ferric reducing antioxidant property (FRAP) values in all the spices with high regression coefficients (R²) ranging from 0.952 to 0.999.     

Determination of macronutrients and some essential elements in the slovene military diet

The energy and nutrient values for military nutrition are defined in the nutritional recommendations of the Slovene Armed Forces. In this study 35 daily military diets sampled in the years 2002 and 2005 by the double basket method were analysed, for energy, total fat, protein, dietary fibre and the elements Ca, Mg, Na, P, K, Fe, Zn, Cu, I and Se. The daily diets were collected at different locations in Slovenia. The aim was to establish whether energy value, content of fat, protein, dietary fibre and selected essential elements are in compliance with the nutritional recommendations of the Slovene Armed Forces. The results indicate that daily intake of essential elements from military meals was sufficient, with the exception of Ca and Zn in diets sampled in 2005. The study was the first in Slovenia analysing daily intakes of essential elements in an adult population aged 19–27 years.     

Effect of acute consumption of oolong tea on antioxidant parameters in healthy individuals

We evaluated the ability of a ready-to-drink oolong tea (OOL) to modulate plasma antioxidant status in healthy subjects, compared to a placebo drink (PLA) without oolong extract but with ascorbic acid. In vitro, ascorbic acid was the only contributor to ferric reducing antioxidant power (FRAP) and total radical-trapping antioxidant parameter (TRAP) assay of PLA. Ascorbic acid contributed 16.5% and 9.7% of the antioxidant capacity of OOL. In vivo, ingestion of 500 mL of OOL significantly increased plasma TRAP at 30 min and 1 h, compared to 500 mL of PLA, which was ineffective. Plasma FRAP significantly increased at 1, 2 and 4 h for OOL and at 2 h for PLA. Both PLA and OOL significantly increased urinary FRAP over 0–5 h. Urinary FRAP levels went back to baseline at 5 h for PLA tea and remained higher for OOL tea in the interval time 5–12 h (p < 0.01). OOL represents a dietary source of antioxidants able to modulate antioxidant status in humans.     

Study of polyphenol content in the seeds of red grape (Vitis vinifera L.) varieties cultivated in Turkey and their antiradical activity

The polyphenolic content and antioxidant capacity in the seeds of 11 red grape varieties (five international and six native) widely cultivated in Turkey were investigated. Total phenolic, total flavanol and total polymeric procyanidin content ranged from 79.2 to 154.6, 89.2 to 179.4, and 27.0 to 43.3 mg/g seed, respectively. While (+)-catechin (4.71–23.8 mg/g seed) was found as main flavanol, galloylated catechin monomer and dimeric procyanidin amounts varied between 2.89–17.2 and 0.97–2.97 mg/g seed, respectively. All seed extracts showed remarkable DPPH radical scavenging activity (EC₅₀) and oxygen radical scavenging capacity (ORAC) ranging from 2.71 to 4.62 μg/mL and 1425.9 to 3009.2 μmol Trolox equivalent/g seed, respectively. With high amount of total phenolic content and antioxidant activity, seeds of Okuzgozu, Papaz Karasi, Ada Karasi and Kalecik Karasi varieties could be evaluated as dietary supplement.     

Principal phenolic phytochemicals and antioxidant activities of three Chinese medicinal plants

The principal antioxidant components and content of cinnamon (Cinnamomum cassia), turmeric (Curcuma longa) and golden thread (Coptidis rhizoma) extracts were determined using high performance liquid chromatography (HPLC) with UV detection. In general, C. cassia, C. longa and C. rhizoma extracts from domestic Taiwan were rich in cinnamaldehyde, curcumin, and berberin, respectively. The contents of cinnamaldehyde, curcumin, and berberin in the acetone extracts were 1911, 2029, and 840 mg l⁻¹, respectively. The Folin–Ciocalteu method was used to measure the total phenolic concentrations of extracts, which had the content of 9.6 (C. cassia), 2.6 (C. longa), and 4.3 (C. rhizoma) mM l⁻¹. In addition, DPPH radical-scavenging, ferric-reducing antioxidant power (FRAP), and ferric thiocyanate (FTC) assays were employed to measure antioxidant activities. The C. cassia fresh extracts had higher antioxidant activities which were 84–90% (DPPH), 17–33 μmol l⁻¹ (FRAP), and 53–82% (FTC). The activities of C. longa fresh extracts were 22–44% (DPPH), 7–11 μmol l⁻¹ (FRAP), and 53–81% (FTC) while C. rhizoma were 53–64% (DPPH), 18–26 μmol l⁻¹ (FRAP), and 59–82% (FTC).     

Optimisation of octadecyl (C18) sorbent amount in QuEChERS analytical method for the accurate organophosphorus pesticide residues determination in low-fatty baby foods with response surface methodology

Three low-fatty baby food matrices were fortified with 0.01–0.2 mg/kg of phorate, diazinon, chlorpyrifos and methidathion. A “quick, easy, cheap, effective, rugged and safe” – like method (QuEChERS) was used. Quantities of octadecyl (C₁₈) sorbent differed with fortification level and matrix fat, based on central composite experimental design. Quantification was performed by Nitrogen–Phosphorus Detector gas chromatography, using matrix-matched standards. The highest (p < 0.05) recoveries were observed for methidathion, the lowest fortification levels for a specific C₁₈ amount and the lowest C₁₈ amounts. In meals containing vegetables (1.9% fat) and lamb (3.0% fat), 180–210 mg C₁₈ gave recoveries from 67.0% to 105.0% and absence of co-extracts. Yogurt dessert (4.5% fat) required 200–230 mg C₁₈ for similar results. Recoveries could also be predicted with <20% error by a polynomial model. The results suggest that modified QuEChERS could be effectively used in the low-fatty baby meals residue analysis.     

Unfermented and fermented rooibos teas (Aspalathus linearis) increase plasma total antioxidant capacity in healthy humans

The aim of the study was to assess the effect of drinking rooibos tea (Aspalathus linearis) on total antioxidant capacity (TAC), lipid triacylglycerols, cholesterol and glycaemia plasma levels in humans. In vitro, unfermented rooibos tea displayed a 28% higher value of TRAP than did the fermented beverage. An acute intervention study, cross-over design, was performed, with 15 healthy volunteers who consumed 500 ml of either water, unfermented or fermented rooibos teas. Plasma antioxidant capacity increased significantly with both teas, reaching a peak at 1 h post-consumption (+6.6%, p < 0.05 fermented tea; +2.9%, p < 0.01 unfermented tea). No changes in triacylglycerols, cholesterol or uric acid were observed with any of the treatments. A transitory increase in glycaemia at 30 min was linked to glucose upload. The data show that rooibos teas represent a source of dietary antioxidants in humans.     

Anti-oxidative analysis,and identification and quantification of anthocyanin pigments in different coloured rice

Anthocyanin pigments in coloured rice cultivars were isolated and identified using high-performance liquid chromatography techniques. Two black rice cultivars (Asamurasaki, Okunomurasaki) contained three major anthocyanins: cyanidin-3-glucoside, peonidin-3-glucoside and malvidin. Chinakuromai (black) rice additionally contained a fourth anthocyanin, petunidin-3-glucoside. Four red rice cultivars contained only malvidin. The total anthocyanin content varied greatly among black rice cultivars (79.5–473.7 mg/100 g), but was lower in red rice (7.9–34.4 mg/100 g). Total phenolic content was similar between red (460.32–725.69 mg/100 g) and black (417.11–687.24 mg/100 g) rice. The oxygen radical absorbing capacity was ranked as follows: red (69.91–130.32 μmol Trolox/g) > black (55.49–64.85 μmol Trolox/g) > green (35.32 μmol Trolox/g) > white (21.81 μmol Trolox/g) rice. The antioxidant capacity resulted mainly from the seed capsule, not the endosperm. The anthocyanin pigments contributed little to the total antioxidant capacity of red (0.03–0.1%) and black (0.5–2.5%) rice cultivars. Hence, the antioxidant capacity is derived mainly from other phenolic compounds.     

Impact of the Maillard reaction on the antioxidant capacity of bovine lactoferrin

Studies raise the notion that the Maillard reaction (MR) may be harnessed to modify the antioxidant capacity of alimentary proteins. However, little is known about the impact of MR on bioactive proteins. Glucose and fructose were used as model moieties reacting with lactoferrin (LF). UV absorbance and SDS–PAGE analyses were used to monitor MR progression during 36 h of mild thermal processing (60 °C, 79% RH). FTIR and CD did not reveal changes in LF structure; However, dynamic light scattering showed MR increased mean particle sizes and sample turbidity at 3 < pH < 10. DPPH and FRAP antioxidant assays showed marked increases in antioxidant capacity of Maillard conjugates as a function of reaction time (12 and 36 h), protein:monosaccharide mole ratio (1:1 or 1:3) and moiety type, compared to unprocessed LF. Overall, a link between conjugates’ antioxidant capacity and processing parameters is described to enable future attempts to enhance LF functionality in foods containing carbohydrates.     

Nutrient composition and physicochemical properties of Indian medicinal rice – Njavara

Njavara, a medicinal rice, was assessed for its nutrient composition and physicochemical properties, in order to understand its therapeutic properties. Dehusked Njavara rice consisted of 73% carbohydrates, 9.5% protein, 2.5% fat, 1.4% ash and 1628 kJ per 100 g of energy. Physicochemical properties and nutritive components of dehusked rice of Njavara were evaluated and compared with two commonly consumed non-medicinal rice varieties – Jyothi (red coloured) and IR 64 (brown coloured). The carbohydrates, fats, apparent amylose equivalent, fatty acid profile and triglycerides of Njavara were comparable to Jyothi and IR 64. However, Njavara rice had 16.5% higher protein, and contained higher amounts of thiamine (27–32%), riboflavin (4–25%) and niacin (2–36%) compared to the other two rice varieties. The total dietary fibre content in Njavara was found to be 34–44% higher than that of Jyothi and IR 64. Significantly higher phosphorus, potassium, magnesium, sodium and calcium levels were found in Njavara rice, compared to the other two varieties. The cooking time of dehusked Jyothi and IR 64 varieties were found to be 30 min, while Njavara needed longer time to cook, (38 min). The cooked rice of Njavara was slimy in nature, probably due to the presence of non-starch polysaccharides.     

Organic acids,antioxidant capacity,phenolic content and lipid characterisation of Georgia-grown underutilized fruit crops

Four underutilized Georgia-grown fruit crops, namely loquat (Eriobotrya japonica), mayhaw (Crataegus sp.), fig (Ficus carica), and pawpaw (Asimina triloba), and their leaves were analysed for total polyphenols by Folin–Ciocalteau method, and antioxidant capacity by ferric-reducing antioxidant power (FRAP) and Trolox-equivalent antioxidant capacity (TEAC) assays. Organic acids and phenolic compounds were identified by RP-HPLC. For lipid profile, fruits were separated into two fractions – seed and fruit (i.e., without seed); lipid was extracted using the Folch method and analysed for fatty acids, phytosterols, tocopherols, and phospholipids. The major organic acid identified in all samples was malic acid (177–1918 mg/100 g FW). The predominant phenolic acids in all the fruits were gallic (1.5–6.4 mg/100 g FW) and ellagic (0.2–33.8 mg/100 g FW), and the most abundant flavonoid was catechin (12.2–37.8 mg/100 g FW). Total lipid content varied from 0.1% in mayhaw fruit to 21.5% in pawpaw seed. Linoleic acid was the predominant fatty acid in all of the samples (28.2–55.7%).