Analysis of total glucosinolates and chromatographically purified benzylglucosinolate in organic and conventional vegetables

The limited availability of foods that are free of pesticides has led Brazil to search for alternative production methods to meet the desires of consumers. Currently, organic cultivation represents a production system that complies with general expectations of producers and consumers. Organic cultivation is particularly interesting mainly because of its effect on plant secondary metabolite content, which may help plants to naturally combat pests; in humans, these substances can also contribute to the prevention of chronic diseases. We report on the extraction of glucosinolates (both as total glucosinolates and as benzylglucosinolate) with trifluoroacetic acid addition in a 70:30 MeOH:water (v/v). Total glucosinolates, determined by a thioglucosidase coupled assay, were measured in different Brassicaceae species and were similar to values reported in the literature. For broccoli, analyses were carried out separately on inflorescences, leaves and stalks; analyses were also conducted on thermally processed samples to simulate cooking. Furthermore, when the analysis was conducted on conventional and organic products, the highest concentrations of these substances were most often found in organically cultivated Brassicaceae. The benzylglucosinolate concentrations were evaluated on the same samples using HPLC. The concentration of benzylglucosinolate was significantly higher in organically cultivated vegetables, as well. © 2012 Elsevier Ltd.

Exportação de nutrientes em plantas de jambu, sob diferentes adubações

The jambu is a broad vegetable consumption in Northern Brazil, especially in Pará, known by the jambu and other common names is native to the Amazon region has been used and cultivated for culinary and also recently in natural medicines by their chemical properties, attributed to the spilanthol compound. Knowing the amount of nutrient uptake in plants, especially at the taken, it is important to evaluate the removal of nutrients necessary for economic fertilizer recommendations. So the goal of this project was to determine the accumulation of nutrients in plants of jambu (leaf and inflorescence) under different fertilizations. The experiment was conducted at São Manuel Experimental Farm UNESP. The statistical was arranged in the randomized block design, in a 2 x 6 factorial scheme, two sources of fertilizers (organic and mineral) and six doses of nitrogen, with four replications. We evaluated the macronutrients of accumulation N, P, K, Ca, Mg, S and micronutrients of accumulation B, Cu, Fe and Zn in leaves and inflorescence. The plants responded more jambu nutrients of translocation phosphorus (P), magnesium (Mg), sulfhur (S), boron (B), copper (Cu) and iron (Fe) in the inflorescences and phosphorus (P), calcium (Ca), manganese (Mg), sulfur (S), boron (B), copper (Cu) and iron (Fe) in leaves to organic fertilization demonstrating the effectiveness of using this source of fertilizer nutrients indicating that this was a defining characteristic in response to the accumulation of nutrients in the leaves and inflorescences jambu. Plants jambu are more responsive to fertilizer for the mineral of translocation nitrogen (N) and manganese (Mn) for both the sheet and for the inflorescences of plants jambu.

Produtividade e acúmulo de nutrientes em plantas de jambu, sob adubação orgânica e mineral

The organic production is a system that allows achieving good levels of productivity, while avoiding the risks of chemical contamination of farmers, consumers and the environment. Because jambu plant is widely used as alternative medicine and cosmetics industries, has been increasing interest in its cultivation. The aim of this study was to analyze the biomass, accumulation of nutrient, productivity and determine the pesticide residue in plant jambu when grown under organic and mineral fertilization. The experiment was conducted at the Experimental Farm São Manuel, FCA / UNESP. The experiment was conducted at São Manuel Experimental Farm UNESP. The statistical was arranged in the randomized block design, in a 2 x 6 factorial scheme, two sources of fertilizers (organic and mineral) and six doses of nitrogen, with four replications. The characteristics evaluated were plant height, fresh and dry weight, nutrients of accumulation in shoots and productivity. Mineral fertilizer gave higher biomass, productivity and accumulation of N and K in relation to organic fertilizer used. It is recommended the dose of 90g m -2 of urea as appropriate to obtain these results. However the organic fertilization favored the accumulation of phosphorus in plants jambu in relation the mineral fertilizer, and the dose of 10 kg m-2 of cattle manure recommended to achieve this result in plants jambu. We did not detect the presence of phosphorous and carbamate on leaves of jambu under organic and mineral fertilization. However, we observed the presence of chlorine in the leaves used for the two fertilizations.

Determination of Total Nitrosamines in Vegetables Cultivated Organic and Conventional Using Diamond Electrode

Vegetables were analyzed for total N-nitrosamines (NAs) and the influence of disinfection processes was assessed. Differences in NAs found in cabbage, spinach, and broccoli were determined by square wave voltammetry using a boron-doped diamond electrode. Analysis of samples showed that all samples contained detectable levels of NAs but the results indicated that organic contained less than conventionally grown products. The sum of the total NAs was higher in the cabbage samples, ranging between 2.8-3.1 ppb and lower in broccoli samples at 0.2-1.1 ppb. The method described is simple, rapid, selective, and sensitive. The results suggested that the disinfection process affects the level of NAs, in this manner affecting the level of human exposure to NAs. © 2012 Springer Science+Business Media New York.

Polyphenoloxidase activity in peaches after vibration

The vibration during transportation is one of the main causes of fruit damage. The actual methodologies used for damage evaluation in fruits seem to be subjective, since most of them are based on visual evaluation. In this study the effect of vibration, for one and two hours, on polyphenoloxidase (PPO) activity in peach pulp was investigated. The relation among PPO activity variation, postharvest time and resting time were also considered. Results showed that vibration affects PPO activity. However, it was not possible to correlate PPO activity variation and vibration.

Antioxidant properties of brazilian tropical fruits by correlation between different assays

Four different assays (the Folin-Ciocalteu, DPPH, enzymatic method, and inhibitory activity on lipid peroxidation) based on radically different physicochemical principles and normally used to determine the antioxidant activity of food have been confronted and utilized to investigate the antioxidant activity of fruits originated from Brazil, with particular attention to more exotic and less-studied species (jurubeba, Solanum paniculatum; pequi, Caryocar brasiliense; pitaya, Hylocereus undatus; siriguela, Spondias purpurea; umbu, Spondias tuberosa) in order to (i) verify the correlations between results obtained by the different assays, with the final purpose to obtain more reliable results avoiding possible measuring-method linked mistakes and (ii) individuate the more active fruit species. As expected, the different methods give different responses, depending on the specific assay reaction. Anyhow all results indicate high antioxidant properties for siriguela and jurubeba and poor values for pitaya, umbu, and pequi. Considering that no marked difference of ascorbic acid content has been detected among the different fruits, experimental data suggest that antioxidant activities of the investigated Brazilian fruits are poorly correlated with this molecule, principally depending on their total polyphenolic content. © 2013 Elena Gregoris et al.

Ozonated water and chlorine effects on the antioxidant properties of organic and conventional broccoli during postharvest

There is growing interest in studies on sanitizers other than chlorine that can maintain the quality of organic products without affecting their phytochemical content. The effects of using chlorinated and ozonized water treatments, as sanitizing procedures, on the post-harvest quality of organic and conventional broccoli (Brassica oleracea L.) cv. Italica was evaluated. The biochemical parameters (chlorophyll, polyphenols, flavonoids, vitamin C and antioxidant capacity) of the broccoli samples were analyzed at day (C) (arrival of the plant from the field, original features), and 1, 4 and 7 days after harvest. The polyamine analysis was performed on arrival of the plant from the field and on the first and seventh days. The cultivation procedure influenced polyphenol, vitamin C and total chlorophyll content, and the highest value was observed in organic broccoli after the fourth day. Flavenoid content was higher in organic broccoli. The use of ozone appears not to have had an influence on the amount of polyphenolic, flavonoids and vitamin C during storage. Total chlorophyll content was less affected by ozonized water than by the chlorine treatment as at the first and fourth days of storage. The highest content of putrescine was found in conventional broccoli, while the highest levels of spermidine and spermine were found in organic broccoli. Antioxidant capacity was highest in organic broccoli after day 4 of storage and was affected by the bioactive compounds analyzed. Methods of cultivation influenced natural antioxidant and chlorophyll contents in broccoli under cold storage.

Kinetic role of a histidine residue in the T1 copper site of the laccase from Rigidoporus lignosus

Laccases (benzendiol:oxygen oxidoreductases; EC 1.10.3.2) catalyze the oxidation of a broad range of substrates, such as polyphenols, dyes and pollutants, and thus these enzymes are widely applied in industrial, biotechnological and environmental fields. In order to improve their biotechnological applications, a deep knowledge of structural factors involved in controlling their activity, in various experimental conditions and on different substrates, is required. In the present study, a laccase from the mushroom Rigidoporus lignosus was kinetically characterized. In particular, the stability, the effects of pH, ionic strength and fluoride ion concentration on the kinetic parameters were investigated, using three di-hydroxy-benzene isomers (1,2-dihydroxy-benzene, 1,3-dihydroxy-benzene and 1,4-dihydroxy-benzene) as substrates. The catalytic constant values of the laccase showed a bell-shaped pH profile, with the same optimum pH and pK(a) values for all tested substrates. This behavior appears to be due to the presence of an ionizable residue in the enzyme active site. To identify this residue, the enzyme was derivatized with diethylpyrocarbonate to modify accessible histidine residues, which, according to structural data, are present in the active site of this enzyme. The kinetic behavior of the derivatized laccase was compared with that of the native enzyme and the derivatized residues were identified by mass spectrometry. Mass spectrometry and kinetic results suggest the main role of His-457 in the control of the catalytic activity of laccase from R. lignosus. (C) 2013 Elsevier B.V. All rights reserved.

Ácido 2,3,5-tri-iodobenzoico (TIBA) na micropropagação de abacaxizeiro 'IAC Gomo-de-Mel'

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A magnetically drivable nanovehicle for curcumin with antioxidant capacity and MRI relaxation properties

Curcumin possesses wide-ranging anti-inflammatory and anti-cancer properties and its biological activity can be linked to its potent antioxidant capacity. Superparamagnetic maghemite (gamma-Fe2O3), called surface-active maghemite nanoparticles (SAMNs) were surface-modified with curcumin molecules, due to the presence of under-coordinated Fe-III atoms on the nanoparticle surface. The so-obtained curcumin-modified SAMNs (SAMN@curcumin) had a mean size of 13 +/- 4 nm. SAMN@curcumin was characterized by transmission and scanning electron microscopy, UV/Vis, FTIR, and Mossbauer spectroscopy, X-ray powder diffraction, bulk susceptibility (SQUID), and relaxometry measurements (MRI imaging). The high negative contrast proclivity of SAMN@curcumin to act as potential contrast agent in MRI screenings was also tested. Moreover, the redox properties of bound curcumin were probed by electrochemistry. SAMN@curcumin was studied in the presence of different electroactive molecules, namely hydroquinone, NADH and ferrocyanide, to assess its redox behavior. Finally, SAMN@curcumin was electrochemically probed in the presence of hydrogen peroxide, demonstrating the stability and reactivity of bound curcumin.

Polyamines in tomato plants grown during an incidence of tospovirus exposure

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

MORPHO-PHYSIOLOGICAL INDICES AND ECONOMIC PRODUCTIVITY OF JAMBU CULTIVARS INFLUENCED BY THE ORGANIC AND MINERAL FERTILIZERS

The jambu belongs to the family Asteraceae, tropical crop, nowadays, this plant has been considered as a promising vegetable crop, because to its pharmacological properties. Despite this novelty, the vegetable remains invisible in the statistics of production and market in the state of Para, Brazil. This research was carried out with the aim of comparing the economic productivity and phenological development by the morpho-physiological growth indexes of two cultivars of jambu organic manure and mineral fertilizers. The experiment was carried out at the Sao Manuel Experimental Farm (Sao Manuel-SP), which belongs to the Faculdade de Ciencias Agronomicas - UNESP, campus Botucatu. The experimental design was a factorial randomized blocks (2 x 2) with two fertilization (organic and mineral) and two cultivars (Jambuarana and Nazareth), with six replications, two fertilization (organic and mineral) and two cultivars (Jambuarana and Nazareth). The following characteristics were evaluated: Plant height (cm), Leaf area (cm(2)), Fresh mass (g), Dry mass (g), Leaf area index (LAI), Leaf area ratio (LAR), Specific leaf Area (SLA), Leaf Weight Ratio (LWR), Amount of water in the plant (QAPA) (g per plant set), Leaf specific weight (LSW) (g cm(-2) per plant set) and Economic productivity. All data were statistically analyzed by analysis of variance and the Tukey test (1%) for mean comparison, with the software SISVAR. In the conditions of this experiment was carried out, it was possible to verify that the cultivar Jamburana had not only a good agronomic development and economic productivity under organic fertilization but also the best morpho-physiological indexes, showing that this kind of fertilization increases the agronomic effectiveness of this cultivar.

Phytotoxicity of Solanum aculeatissimum Jacq: leaves extract

The objective of this study was to evaluate the phytotoxicity of Solanum aculeatissimum Jacq. leaves ethanolic extract in seeds germination, development and fixation of Lactuca sativa seedlings. The same study also aimed to assess the mitotic index of lettuce roots meristematic cells, quantification of phenols and total flavonoids and triage by mean of phytochemical testing of the main secondary metabolites classes. Bioassays of germination, development of root and hypocotyl were carried out in Petri dishes using achenes of Lactuca sativa L. cv. 'Grand Rapids' (lettuce). Concomitantly, were evaluated the physico-chemical characteristics (pH, osmotic potential and electrical conductivity), mitotic index, quantification of total phenols and flavonoids and determination of phytochemical profile of the treatments extract. The results obtained in the bioassays demonstrate that the ethanol extract of S. aculeatissimuma presents phytotoxic potential in the development of lettuce seedlings, given that the concentration of 20 mg/ml showed greater inhibition (41% of germination). The extract contains significant amounts of antioxidants, total flavonoid and phenols, where the concentration 1000µg/mL showed higher values (86.50%). Furthermore, it was possible to observe the presence of compounds with allelopathic activity in the phytochemical screening test as coumarins, tannins, terpenes, flavonoids and alkaloids. Given the above it is clear that the ethanolic extract of S. aculeatissimum presents allelopathic substances with phytotoxic activity that can affect the germination and development of other plant species in their natural environment.

Exercise and oxidative stress: p,otential effects of antioxidant dietary strategies in sports

Free radicals are produced during aerobic cellular metabolism and have key roles as regulatory mediators in signaling processes. Oxidative stress reflects an imbalance between production of reactive oxygen species and an adequate antioxidant defense. This adverse condition may lead to cellular and tissue damage of components, and is involved in different physiopathological states, including aging, exercise, inflammatory, cardiovascular and neurodegenerative diseases, and cancer. In particular, the relationship between exercise and oxidative stress is extremely complex, depending on the mode, intensity, and duration of exercise. Regular moderate training appears beneficial for oxidative stress and health. Conversely, acute exercise leads to increased oxidative stress, although this same stimulus is necessary to allow an up-regulation in endogenous antioxidant defenses (hormesis). Supporting endogenous defenses with additional oral antioxidant supplementation may represent a suitable noninvasive tool for preventing or reducing oxidative stress during training. However, excess of exogenous antioxidants may have detrimental effects on health and performance. Whole foods, rather than capsules, contain antioxidants in natural ratios and proportions, which may act in synergy to optimize the antioxidant effect. Thus, an adequate intake of vitamins and minerals through a varied and balanced diet remains the best approach to maintain an optimal antioxidant status. Antioxidant supplementation may be warranted in particular conditions, when athletes are exposed to high oxidative stress or fail to meet dietary antioxidant requirements. Aim of this review is to discuss the evidence on the relationship between exercise and oxidative stress, and the potential effects of dietary strategies in athletes. The differences between diet and exogenous supplementation as well as available tools to estimate effectiveness of antioxidant intake are also reported. Finally, we advocate the need to adopt an individualized diet for each athlete performing a specific sport or in a specific period of training, clinically supervised with inclusion of blood analysis and physiological tests, in a comprehensive nutritional assessment. (C) 2015 Elsevier Inc. All rights reserved.

Magnetic Purification of Curcumin from Curcuma longa Rhizome by Novel Naked Maghemite Nanoparticles

Naked maghemite nanoparticles, namely, surface active maghemite nanoparticles (SAMNs), characterized by a diameter of about 10 nm, possessing peculiar colloidal stability, surface chemistry, and superparamagnetism, present fundamental requisites for the development of effective magnetic purification processes for biomolecules in complex matrices. Polyphenolic molecules presenting functionalities with different proclivities toward iron chelation were studied as probes for testing SAMN suitability for magnetic purification. Thus, the binding efficiency and reversibility on SAMNs of phenolic compounds of interest in the pharmaceutical and food industries, namely, catechin, tyrosine, hydroxytyrosine, ferulic acid, coumaric acid, rosmarinic acid, naringenin, curcumin, and cyanidin-3-glucoside, were evaluated. Curcumin emerged as an elective compound, suitable for magnetic purification by SAMNs from complex matrices. A combination of curcumin, demethoxycurcumin, and bis-demethoxycurcumin was recovered by a single magnetic purification step from extracts of Curcuma longa rhizomes, with a purity >98% and a purification yield of 45%, curcumin being >80% of the total purified curcuminoids.