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21.
Fallovo C Schreiner M Schwarz D Colla G Krumbein A 《Journal of agricultural and food chemistry》2011,59(8):4198-4207
The effect of three different nitrogen (N) supply forms differing in their ammonium-to-nitrate (NH(4):NO(3)) ratio (100% NH(4), 50% NH(4) + 50% NO(3), 100% NO(3)) under three different levels of daily photosynthetic active radiation (PAR) (low, 5.0; medium, 6.8; high, 9.0 mol m(-2) day(-1)) on a range of desirable health-promoting phytochemicals in Brassica rapa subsp. nipposinica var. chinoleifera and Brassica juncea was determined. The 100% NH(4) supply under medium PAR levels led to the highest concentration of glucosinolates based on a low nitrogen/sulfur ratio as well as high levels of carotenoids in the leaves of both Brassica species. However, the 100% NH(4) supply under low and medium PAR levels resulted in low concentrations of flavonoids based on high N concentration in the leaves. Thus, the data provided here have strong implications for crop management strategies aimed at optimizing both the concentration and composition of a range of phytochemicals. 相似文献
22.
Gattuso G Barreca D Caristi C Gargiulli C Leuzzi U 《Journal of agricultural and food chemistry》2007,55(24):9921-9927
HPLC separation of flavonoids and furocoumarins in the crude juices of three cultivars of Citrus bergamia Risso ("Castagnaro", "Fantastico", and "Femminello") was carried out on a C18 reversed phase column. The analysis was performed in a single run using a DAD detector coupled with an ESI-MS-MS source. Two furocoumarins (bergapten and bergamottin) were detected and quantified simultaneously with the sixteen flavonoid components previously found in industrial bergamot juice. Full characterization of the furocoumarins was performed by (1)H NMR analysis on samples separated by means of preparative HPLC. The free-radical scavenging ability of cultivar juices was assessed by using DPPH radical. The data presented show that the "Femminello" cultivar, even though it is the least common of the three, is by far the richest in health-promoting bioactive compounds (both flavonoids and furocoumarins). Given the range of applications of furocoumarins, the preparative separation described herein is proposed as a simple and rapid method to obtain this class of compounds in good yield from crude juice. 相似文献
23.
Cefarelli G D'Abrosca B Fiorentino A Izzo A Mastellone C Pacifico S Piscopo V 《Journal of agricultural and food chemistry》2006,54(3):803-809
Forty-three secondary metabolites were isolated and characterized from cv. Annurca apple fruit, an apple variety cultivated in the south of Italy. This apple cultivar undergoes a typical reddening treatment after collection. All of the compounds were characterized on the basis of their spectroscopic data. The compounds were tested for their radical-scavenging and antioxidant activities by measuring their capacity to scavenge DPPH* (2,2'-diphenyl-1-picrylhydrazyl radical), H2O2, and NO (nitric oxide) and to inhibit the formation of methyl linoleate conjugated diene hydroperoxides or TBARS (thiobarbituric acid reactive species). 相似文献
24.
Optimization of the solid-liquid extraction conditions for trans-resveratrol, trans--viniferin, ferulic acid, and total phenolics from milled grape canes has been investigated. The temperature and ethanol concentration were found to be major process variables for all responses, whereas the solvent to solid ratio was found not to be significant for any of the responses studied. The yields of trans-resveratrol, trans--viniferin, and total phenolics increased with increasing temperature. Maximum yields of trans-resveratrol (4.25 mg/g dw), trans--viniferin (2.03 mg/g), and total phenolics (9.28 mg/g dw) were predicted from the combination of a moderate ethanol concentration (50-70%) and the highest temperature (83.6 degrees C), whereas an ethanol concentration of 35% at the lowest temperature studied (16.4 degrees C) was optimal for the extraction of ferulic acid (1.05 mg/g dw). Effective diffusivity values of resveratrol in the solid phase, D eff for different extraction conditions, were calculated by fitting the experimental results to a model derived from the Fick's second law. Effective diffusivity of resveratrol in the solid phase varied from 3.1 x 10 (-13) to 26.6 x 10 (-13) m (2) s (-1) with changing extraction conditions. The increase in effective diffusivity of resveratrol was observed with increasing temperature, and the highest predicted level was obtained when using 54% ethanol/water mixture at 83.6 degrees C. The increase in ethanol concentration exhibited the favorable effect up to 50-55%, thereafter effective diffusivity decreased with a further increase in concentration. 相似文献
25.
Barbosa LC Pereira UA Teixeira RR Maltha CR Fernandes SA Forlani G 《Journal of agricultural and food chemistry》2008,56(20):9434-9440
The [4 + 3] cycloaddition of the proper furans with the oxyallyl cation, generated in situ from 2,4-dibromopentan-3-one, produced a series of 8-oxabicyclo [3.2.1]oct-6-en-3-ones. Exposure of the oxabicycles to ozone afforded the corresponding 8,9,10,11-tetraoxatricyclo[5.2.1.1 (2,6)]undecan-4-ones in variable yields (7-100%). The phytotoxic properties of these ozonides (or 1,2,4-trioxolanes) and their oxabicycle precursors were evaluated as the ability to interfere with the growth of Sorghum bicolor and Cucumis sativus seedlings. Among oxabicycles, the highest inhibitory activity was shown by compounds possessing a alpha,beta-unsaturated carbonyl moiety. A differential sensitivity of the two crops was evident with ozonides. The most active compounds were also tested against the weed species Ipomoea grandifolia and Brachiaria decumbens. To the best of our knowledge, this is the first article describing ozonides as potential herbicides. 相似文献
26.
Masino F Montevecchi G Arfelli G Antonelli A 《Journal of agricultural and food chemistry》2008,56(20):9495-9501
In this study, two different doses of commercial beta-glucanase enzyme preparation were tested to verify their effect on wines aged on lees. These wines were compared with two samples with no enzymatic treatment. The former was aged on lees (control), and the latter was readily filtered off from the yeast cell biomass (standard). Analysis of variance (one-way ANOVA), the Tukey test, and principal component analysis (PCA) were applied to all of the samples, which were analyzed for aroma composition, along with galacturonic acid, total acidity, pH, and color. Results showed a large number of statistically significant differences among samples. In general, wines treated with beta-glucanase were characterized by higher concentration of many volatile compounds. The presence of lees and even more the exogenous enzymatic action enhanced almost all volatile compounds. Besides the high presence of ethyl esters, it is worth mentioning the behavior of hexanol and trans-3-hexenol, which are strongly enhanced by the presence of lees and by enzymatic treatments. 相似文献
27.
La Guardia M Venturella G Venturella F 《Journal of agricultural and food chemistry》2005,53(15):5997-6002
Unpublished data on the chemical composition and nutritional value of Pleurotus mushrooms, growing on Umbelliferous plants (Apiaceae), are here reported. Cultivated basidiomata of four different Pleurotus taxa were analyzed in order to evaluate the composition in lipids, sugars, nitrogen, water, vitamins, ashes, and energetic values. The results showed that Pleurotus mushrooms are suitable in every type of diet thanks to their low caloric content, gastronomic value, vitamins, and mineral salt contents. The presence of a high content of vitamin B(12) and riboflavin in Pleurotus nebrodensis is noteworthy. 相似文献
28.
Barbosa LC Rocha ME Teixeira RR Maltha CR Forlani G 《Journal of agricultural and food chemistry》2007,55(21):8562-8569
A series of 12 3-(4-bromobenzyl)-5-(arylmethylene)-5 H-furan-2-one lactones, designed using the naturally occurring toxin nostoclides as a lead structure, were synthesized and screened as potential inhibitors of photosynthetic electron transport. The structures were confirmed by (1)H and (13)C NMR, MS, and IR analyses. Their biological activity was evaluated both in vitro, as the ability to interfere with light-driven reduction of ferricyanide by isolated spinach chloroplasts, and in vivo, as the capability to inhibite the oxygen production by intact Chlorella cells. Some of the compounds exhibited inhibitory properties in the micromolar range against basal and phosphorylating electron flow from water to K 3[Fe(CN) 6], with no effect on uncoupled electron flow. Thus, they seem to behave as energy-transfer inhibitors. Although poor solubility in water may limit their effectiveness, the active derivatives could present structures to be exploited for the design of new substances endowed with herbicidal activity. 相似文献
29.
Venturi L Rocculi P Cavani C Placucci G Dalla Rosa M Cremonini MA 《Journal of agricultural and food chemistry》2007,55(26):10572-10578
Hydration of freeze-dried chicken breast meat was followed in the water activity range of aw=0.12-0.99 by a multianalytical approach comprising of sorption isotherm, differential scanning calorimetry (DSC), and nuclear magnetic resonance (NMR). The amount of frozen water and the shape of the T2-relaxogram were evaluated at each water content by DSC and NMR, respectively. Data revealed an agreement between sorption isotherm and DSC experiments about the onset of bulk water (aw=0.83-0.86), and NMR detected mobile water starting at aw=0.75. The origin of the short-transverse relaxation time part of the meat NMR signal was also reinvestigated through deuteration experiments and proposed to arise from protons belonging to plasticized matrix structures. It is proved both by D2O experiments and by gravimetry that the extra protons not contributing to the water content in the NMR experiments are about 6.4% of the total proton NMR CPMG signal of meat. 相似文献
30.
Mandalari G Bennett RN Bisignano G Saija A Dugo G Lo Curto RB Faulds CB Waldron KW 《Journal of agricultural and food chemistry》2006,54(1):197-203
Bergamot peel is an underutilized byproduct of the essential oil and juice-processing industry. As with other Citrus peels, it still contains exploitable components, such as pectins and flavonoids. Commercial glycoside hydrolases, specifically a combination of pectolytic and cellulolytic enzymes, solubilized a high percentage of the material (81.94%). The flavonoid profile of the peel consisted of characteristic Citrus species flavanone rutinosides and neohesperosides derived from naringenin, eriodictyol, and hesperetin. In addition, a number of minor flavanone and flavone glycosides, not found in orange and lemon peels, were identified. The majority of flavonoids were extracted in the two 70% v/v EtOH extractions. Processing this material clearly has economic potential leading to low environmental impact. 相似文献