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991.
Salvia-Trujillo L Morales-de la Peña M Rojas-Graü A Martín-Belloso O 《Journal of agricultural and food chemistry》2011,59(18):10034-10043
The effect of high-intensity pulsed electric fields (HIPEF) or thermal processes and refrigerated storage on water-soluble vitamins and antioxidant capacity of beverages containing fruit juices and whole (FJ-WM) or skim milk (FJ-SM) was assessed. Peroxidase (POD) and lipoxygenase (LOX) inactivation as well as color changes were also studied. High vitamin C retention was observed in HIPEF and thermally treated beverages, but a significant depletion of the vitamin during storage occurred, which was correlated with antioxidant capacity. HIPEF treatment did not affect the concentration of group B vitamins, which also remained constant over time, but thermally treated beverages showed lower riboflavin (vitamin B2) concentration. With regard to enzyme activity, thermal processing was more effective than HIPEF on POD and LOX inactivation. The color of the beverages was maintained after HIPEF processing and during storage. Consequently, HIPEF processing could be a feasible technology to attain beverages with fruit juices and milk with high vitamin content and antioxidant potential. 相似文献
992.
We investigated the characteristics and variability of radial growth patterns and the occurrence of growth releases in dominant
trees in two old-growth forests in eastern Finland, one dominated by Picea abies and the other by Pinus sylvestris. The dominant trees exhibited high variation in radial growth patterns suggesting that the trees had experienced very different
growing conditions and competitive situations during their lifespans. Based on visual evaluation, five types of radial growth
patterns were distinguished: descending, even, unimodal (one peak in the growth rate), bimodal (two peaks in the growth rate
with an intermediate depression) and fuzzy (no clear pattern). One or more growth releases were detected in 18% of the sampled
Picea and in 21% of the Pinus trees. In both the Picea- and the Pinus-dominated sites, the temporal distribution of growth releases was relatively even, except for a moderate peak in 1855–1860.
This suggests that small-scale disturbances have been the predominant disturbance mode in both sites during the last 150 years.
We conclude that the detected variability in radial growth patterns likely reflects the overall small-scale heterogeneity
of structure and developmental processes that are typical of old-growth forests. 相似文献
993.
Renato Gerdol Alessandro Pontin Marcello Tomaselli Laura Bombonato Lisa Brancaleoni Matteo Gualmini Alessandro Petraglia Chiara Siffi Alessandro Gargini 《CATENA》2011,86(2):86-97
We examined how hydrology influenced water chemistry, vegetation, nutrient status, aboveground net primary production (ANPP) and litter decomposition rates in two mires on the South-Eastern Alps of Italy. One of the mires had a modest hydraulic gradient and prevalently acted as a recharge system, although there were short phases of vertical flow reversal during dry periods. This mire was, therefore, prevalently fed by rainwater and was covered by bog-like vegetation, mainly hummocks and scrubs with a ground layer rich in Sphagnum mosses. The other mire presented a steeper hydraulic gradient, with the surface being fed by mineral water either by surface runoff or by vertical, upwards directed ground water flow. Compared to the bog-dominated mire, the pore water was less acidic and richer in telluric cations. This mire was covered by fen-like vegetation, prevalently fen meadows. Nitrogen (N) content in the vegetation was very similar in the two mire sites, while phosphorus (P) content was lower in the fen-dominated site. Contrary to our expectations, ANPP did not differ significantly between the two mire sites while litter decomposition rates were significantly lower in the fen-dominated mire, presumably because of P limitation of decomposers. This suggests that the development of ombrogenous mires in this region need not be due to increased accumulation of peat during succession from mineralwater-fed to rainwater-fed conditions. 相似文献
994.
Fragoso S Aceña L Guasch J Mestres M Busto O 《Journal of agricultural and food chemistry》2011,59(20):10795-10802
We present a rapid method to quantify phenolic compounds all during the red winemaking process using Fourier transform mid-infrared (FT-MIR) spectroscopy and chemometrics. To get the reference values, we used the usual UV–vis spectroscopy methods, and the compounds studied were evaluated as total phenolic compounds (TPC), total anthocyanins (TA), and condensed tannins (CT). Sampling from five different grape varieties (Merlot, Tempranillo, Syrah, Cari?ena, and Cabernet sauvignon), harvested at different ripening states, and monitored over 10 days of vinification produced a total of 600 spectra. These were used to build and validate four different predictive models by partial least-squares (PLS) regression. The spectral regions selected for each model were between 979 and 2989 cm(–1), and when selecting the most suitable one in each case, good values of performance parameters were obtained (R2(val) > 0.95 and RPD > 4.0 for TPC; R2(val) > 0.90 and RPD > 3.0 for TA; R2(val) < 0.8 and RPD < 3.0 for CT). Furthermore, also more specific PLS regression models for each phenolic parameter and each grape variety were developed using different regions with results similar to those obtained when dealing with all of the grape varieties. It is concluded that FT-MIR spectroscopy together with multivariate calibration could be a rapid and valuable tool for wineries to carry out the monitoring of phenolic compound extraction during winemaking. 相似文献
995.
Hernández-Hernández O Ruiz-Aceituno L Sanz ML Martínez-Castro I 《Journal of agricultural and food chemistry》2011,59(6):2451-2455
Different low molecular weight carbohydrates including saccharides, polyalcohols, sugar acids, and glycosides have been identified and quantified in different edible vegetables from Asteraceae, Amarantaceae, Amarylidaceae, Brassicaceae, Dioscoreaceae, and Solanaceae families by gas chromatography-mass spectrometry. Apart from glucose, fructose, and sucrose, other saccharides such as sedoheptulose in chicory, spinach, cabbage, purple yam, eggplant, radish, and oak leaf lettuce, rutinose in eggplant skin, and a glycosyl-inositol in spinach have been identified. chiro-Inositol was found in all vegetables of the Asteraceae family (3.1-32.6 mg 100 g(-1)), whereas scyllo-inositol was detected in those of purple yam, eggplant, artichoke, chicory, escarole, and endive (traces-23.2 mg 100 g(-1)). α-Galactosides, kestose, glucaric acid, and glycosyl-glycerols were also identified and quantified in some of the analyzed vegetables. Considering the bioactivity of most of these compounds, mainly chicory leaves, artichokes, lettuces, and purple yam could constitute beneficial sources for human health. 相似文献
996.
Pereira-Caro G Sarriá B Madrona A Espartero JL Goya L Bravo L Mateos R 《Journal of agricultural and food chemistry》2011,59(11):5964-5976
Alkyl hydroxytyrosyl ethers (methyl, ethyl, propyl, and butyl ethers) have been synthesized from hydroxytyrosol (HTy) in response to the increasing food industry demand of new lipophilic antioxidants. Having confirmed that these compounds reach portal blood partially unconjugated and thus are effectively absorbed, their potential antioxidant activity was evaluated in the human hepatocarcinoma cell line (HepG2). The effects of 0.5-10 μM alkyl hydroxytyrosyl ethers on HepG2 cell integrity and redox status were assessed as well as the protective effect against oxidative stress induced by tert-butylhydroperoxide (t-BOOH). Cell viability (Crystal violet) and cell proliferation (BrdU assay) were measured as markers of cell integrity, concentration of reduced glutathione (GSH), generation of reactive oxygen species (ROS), and activity of antioxidant enzymes glutathione peroxidase (GPx) and glutathione reductase (GR) as markers of redox status and determination of malondialdehyde (MDA) as a marker of lipid peroxidation. Direct treatment of HepG2 with alkyl hydroxytyrosyl ethers induced slight changes in cellular intrinsic antioxidants status, reducing ROS generation and inducing changes in GPx and GR activities. Pretreatment of HepG2 cells with alkyl hydroxytyrosyl ethers counteracted cell damage induced by t-BOOH, partially after 2 h and completely after 20 h, by increasing GSH and decreasing ROS generation, MDA levels, and antioxidant enzyme (GPx and GR) activity. According to these results the alkyl hydroxytyrosyl ethers show clear protective effects against oxidative stress, related to their lipophilic nature, that are similar to or even higher than those of their precursor, HTy. 相似文献
997.
998.
Helmuth L 《Science (New York, N.Y.)》2002,297(5585):1262-1263
999.
King-Casas B Sharp C Lomax-Bream L Lohrenz T Fonagy P Montague PR 《Science (New York, N.Y.)》2008,321(5890):806-810
To sustain or repair cooperation during a social exchange, adaptive creatures must understand social gestures and the consequences when shared expectations about fair exchange are violated by accident or intent. We recruited 55 individuals afflicted with borderline personality disorder (BPD) to play a multiround economic exchange game with healthy partners. Behaviorally, individuals with BPD showed a profound incapacity to maintain cooperation, and were impaired in their ability to repair broken cooperation on the basis of a quantitative measure of coaxing. Neurally, activity in the anterior insula, a region known to respond to norm violations across affective, interoceptive, economic, and social dimensions, strongly differentiated healthy participants from individuals with BPD. Healthy subjects showed a strong linear relation between anterior insula response and both magnitude of monetary offer received from their partner (input) and the amount of money repaid to their partner (output). In stark contrast, activity in the anterior insula of BPD participants was related only to the magnitude of repayment sent back to their partner (output), not to the magnitude of offers received (input). These neural and behavioral data suggest that norms used in perception of social gestures are pathologically perturbed or missing altogether among individuals with BPD. This game-theoretic approach to psychopathology may open doors to new ways of characterizing and studying a range of mental illnesses. 相似文献
1000.