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21.
Elías J. Mongiardini Julieta Prez-Gimnez M. Julia Althabegoiti Julieta Covelli J. Ignacio Quelas Silvina L. Lpez-García Aníbal R. Lodeiro 《Soil biology & biochemistry》2009,41(9):2017-2020
Competition for nodulation is a complex problem where bacterial adhesins, which are required for root colonization, may play a role. However, the possible influence of adhesins on competitiveness was scarcely studied. In this work, the Rhizobium leguminosarum bv trifolii adhesion protein RapA1 was overproduced from a pHC60-derived plasmid and expressed in R200 strain. When an overproducing strain and a control-carrying empty vector were co-inoculated on clover plants, a positive effect of RapA1 on competition for nodule occupation was observed. Therefore, optimization of RapA1 expression may be considered for improvement of rhizobial competitiveness. 相似文献
22.
Rosa Palmeri Cristina Restuccia Julieta Ines Monteleone Elisa Sperlinga Laura Siracusa Mauro Serafini Alberto Finamore Giovanni Spagna 《Plant foods for human nutrition (Dordrecht, Netherlands)》2017,72(2):211-218
Olive leaves represent a quantitatively significant by-product of agroindustry. They are rich in phenols, mainly oleuropein, which can be hydrolyzed into several bioactive compounds, including hydroxytyrosol. In this study, water extract from olive leaves ‘Biancolilla’ was analyzed for polyphenol profile, DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity and protective effect on differentiated Caco-2 cells. The efficacy of two enzymatic treatments in promoting the release of bioactive phenols was investigated: a) enzymatic extract from Wickerhamomyces anomalus, characterized by β-glucosidase and esterase activities; b) commercial β-glucosidase. Composition and bioactivity of the resulting extracts were compared. The results showed that the yeast-treated extract presented hydroxytyrosol content and DPPH radical scavenging activity comparable to those obtained using commercial β-glucosidase; however, it was showed the additional presence of hydroxycinnamic acids. In experiments on Caco-2 cells, the leaf extracts promoted the recovery of cell membrane barrier at different minimum effective concentrations. The high specificity of W. anomalus enzymatic extract may represent an effective tool for the release of bioactive phenols from olive by-products. 相似文献
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24.
Lopez-Toledano A Villaño-Valencia D Mayen M Merida J Medina M 《Journal of agricultural and food chemistry》2004,52(8):2376-2381
The condensation reaction between (+)-catechin and acetaldehyde was studied in model solutions in the presence and absence yeasts in order to evaluate its contribution to color changes in fermented drinks such as white wine. On the basis of the results, the yeasts retain the oligomers produced in the reaction, their retention ability increasing for higher polymerization degrees. As a result, the color of model solutions, measured as the absorbance at 420 nm, was found to decrease after the addition of yeasts. On the other hand, the yeasts exhibited no inhibitory effect on the condensation reaction, which took place at the same rate in their presence and absence. At acidity levels and reactant concentrations similar to those in wine, with acetaldehyde in high concentration as it is present in sherry wines, the reaction was found to occur very slowly. Taking into account that Yeasts are present during most of the winemaking process; consequently, they retain oligomers, and the studied reaction could mainly contribute to the alteration of the color of white wine after bottling. 相似文献
25.
Menezes EW Tadini CC Tribess TB Zuleta A Binaghi J Pak N Vera G Dan MC Bertolini AC Cordenunsi BR Lajolo FM 《Plant foods for human nutrition (Dordrecht, Netherlands)》2011,66(3):231-237
Banana flour obtained from unripe banana (Musa acuminata, var. Nanicão) under specific drying conditions was evaluated regarding its chemical composition and nutritional value. Results are expressed in dry weight (dw). The unripe banana flour (UBF) presented a high amount of total dietary fiber (DF) (56.24 g/100 g), which consisted of resistant starch (RS) (48.99 g/100 g), fructans (0.05 g/100 g) and DF without RS or fructans (7.2 g/100 g). The contents of available starch (AS) (27.78 g/100 g) and soluble sugars (1.81 g/100 g) were low. The main phytosterols found were campesterol (4.1 mg/100 g), stigmasterol (2.5 mg/100 g) and β-sitosterol (6.2 mg/100 g). The total polyphenol content was 50.65 mg GAE/100 g. Antioxidant activity, by the FRAP and ORAC methods, was moderated, being 358.67 and 261.00 μmol of Trolox equivalent/100 g, respectively. The content of Zn, Ca and Fe and mineral dialyzability were low. The procedure used to obtain UBF resulted in the recovery of undamaged starch granules and in a low-energy product (597 kJ/100 g). 相似文献
26.
Julieta R. Mendieta Carmela Fimognari Gustavo R. Daleo Patrizia Hrelia María G. Guevara 《Fitoterapia》2010,81(5):329-335
StAPs are potato aspartic proteases with cytotoxic activity against plant pathogens and spermatozoa. StAPs cytotoxic activity is selective, since these proteins do not exert toxic effect on plant cells and erythrocytes. In this work, we investigated the capacity of StAPs to exert cytotoxicity on human leukaemia cells. Obtained results show that StAPs induce apoptosis on Jurkat T cells after a short time of incubation in a dose-dependent manner. However, no significative effect on the T lymphocytes viability was observed at all StAPs incubation times and concentrations tested. These results suggest that StAPs can be conceptually promising leads for cancer therapy. 相似文献
27.
Pedraza-Beltrán P Estrada-Flores JG Martínez-Campos AR Estrada-López I Rayas-Amor AA Yong-Angel G Figueroa-Medina M Nova FA Castelán-Ortega OA 《Tropical animal health and production》2012,44(2):329-336
Tropical grasses are the primary nutrient resource for cattle production in the tropics, and they provide low-cost nutrients
to cattle. However, its production is constrained by seasonal changes and quality; hence, appropriate usage of relatively
inexpensive agricultural by-products is important to profitable livestock production. The objective of the study was to evaluate
the effect of supplementing coffee pulp to dairy cows grazing tropical grasses on milk yield and forage intake. Four multiparous
crossed Holstein–Brown Swiss–Zebu cows of similar weight and milk yield were used. The effect of 10%, 15% and 20% inclusion
of coffee pulp in dairy concentrates on milk yield and forage intake was analysed using a 4 × 4 Latin square design. Results
showed that there were no significant effects (P > 0.05) in grass dry matter intake, milk yield, milk composition body weight and body condition score due to the inclusion
of coffee pulp in the dairy concentrates. It is concluded that coffee pulp can be included at levels of 20% in the concentrate
without compromising significantly (P > 0.05) milk yield, milk composition and grass dry matter intake. It also was concluded that cost of concentrate is reduced
in 20% by the inclusion of coffee pulp. 相似文献
28.
Pereda J Ferragut V Quevedo JM Guamis B Trujillo AJ 《Journal of agricultural and food chemistry》2008,56(16):7125-7130
Free fatty acid (FFA) release and quantification and lipid oxidation extent of ultra-high-pressure homogenized (UHPH) milk samples were evaluated to assess the effect of UHPH on the susceptibility of milk lipids to lipolysis and oxidation. Milk was UHPH-treated at 200 and 300 MPa with inlet temperatures of 30 and 40 degrees C. UHPH-treated samples were compared to high-pasteurized milk (PA; 90 degrees C, 15 s). Results showed that all FFA increased significantly during storage only in 200 MPa samples. Lipid oxidation was measured as an accumulation of lipid hydroperoxides as the primary oxidation product and malondialdehyde and hexanal as the secondary oxidation products. Samples treated at 300 MPa presented higher malondialdehyde and hexanal content compared to 200 MPa treated-samples and to PA milk. 相似文献
29.
Serratosa MP Lopez-Toledano A Merida J Medina M 《Journal of agricultural and food chemistry》2008,56(8):2810-2816
Changes in color parameters and phenolic compounds during the sun-drying grape raisining of cv. Pedro Ximenez to obtain sweet wines are studied. Browning increases during the process as a result of the contribution to a greater extent of the low and medium molecular size polymers than the high molecular size polymers. Raisining decreases hue and lightness and increases chroma, all measured as CIELab parameters, indicating a color change to dark reddish hues that is also preferentially due to low and medium molecular size polymers. Most of the phenols studied increase in concentration during raisining, essentially through the concentration effect resulting from the loss of water in the grapes. The concentration changes, however, are comparatively small for hydroxycinnamic esters and flavan-3-ol derivatives, suggesting that these phenolic fractions undergo predominantly oxidative degradation reactions by enzymatic pathways, contributing strongly to the browning of grapes. 相似文献