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1.
Neodymium and praseodymium ions, singly and in combination, have been doped into a poly(vinyl alcohol)–borax matrix. X-ray diffraction shows structural correlations from 2 to 6 Å and 15 Å, while small angle neutron scattering indicates that the rare-earth ions do not affect the nanoscale structures of the gels. Differential scanning calorimetry shows the glass transition temperature to increase with concentration of Pr in the gel. Excitation in the ultraviolet region leads to luminescent emission in the visible region. Simultaneous absorption in the visible region then leads to luminescent emission in the near infra-red region. The spectral qualities of the emission bands can be varied by choosing appropriate relative ratios of rare-earth species. 相似文献
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C-calculus was introduced by the first author as a technique for the analysis of complex hierarchical systems.2 It has been further applied as a versatile tool in pattern recognition.1,3 Our present aim is to exhibit a model for C-calculus, and deal with its convergence and filtering properties. 相似文献
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LILIANA BUSCONI EDUARDO J. FOLCO CELINA B. MARTONE JORGE J. SANCHEZ 《Journal of Food Biochemistry》1989,13(6):443-451
Transmission electron microscopic examination of samples from fresh and 7 days-cold-stored white croaker skeletal muscle did not reveal apparent changes in overall structure of contractile elements of muscle. However, when purified myofibrils obtained from fresh and stored muscles were extracted with 0.6 M KI and the residues were examined in the scanning electron microscope, a progressive disappearance of exosarcomeric longitudinal filaments connecting successive Z structures was observed. Electrophoretic analysis of myofibrillar proteins obtained from fresh and stored muscles showed a marked degradation of nebulin, a major component of the endosarcomeric cytoskeletal network, whereas the other protein constituents of myofibrils remained practically unchanged. These alterations in elements of both cytoskeletal lattices of muscle may have important effects on physical properties of fish meat. 相似文献
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FARIDAH MOHD-SOM EDUARDO KERBEL SCOTT E. MARTIN SHELLY J. SCHMIDT 《Journal of food quality》1994,17(5):347-360
Changes in the microflora of packaged (Resinite VF-71 film) and nonpackaged broccoli florets held at 8C for 7 days were analyzed. Oxygen and carbon dioxide concentrations, aerobic plate, coliform yeast/mold counts, and overall quality were determined. Level of O2 decreased from 15.58 to 5.15%, while CO2 increased from 2.88 to 8.22% after 94 h of storage. Within each microorganism group, similar growth trends were observed between the packaged and nonpackaged samples; however, the packaged samples consistently exhibited a statistically significant (p ≤ 0.05) lower microbial count compared with nonpackaged samples throughout the storage period. Packaged and nonpackaged florets retained their green color and no off-odor was detected; however, the nonpackaged florets were found to be less crispy than the packaged samples. 相似文献
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MAURO RODRIGO SURENCISKI EDUARDO ALBERTO FLACHSLAND GRACIELA TERADA LUIS AMADO MROGINSKI HEBE YOLANDA REY 《Biocell》2012,36(1):31-36
The aim of the present study was to investigate the efficiency of the encapsulation-dehydration technique for cryopreservation of Cyrtopodium hastchbachii Pabst seeds. Immature seeds of this species were cryopreserved by an encapsulation-dehydration technique. Seeds of five immature pods, 120 days after pollination, were encapsulated in 3% calcium alginate matrix and pretreated in liquid medium supplemented with 0.08 M sucrose (24 h), 0.15 M sucrose (24 h), 0.25 M sucrose (48 h), 0.5 M sucrose (24 h) and 0.75 M sucrose (24 h) in shaker at 60 rpm. Alginate beads were dehydrated 5 h in silicagel and immersed in liquid nitrogen for 12 h. Cryopreserved beads were thawed at 30°C for 1 min, rehydrated using the same liquid mediums [0.75 M sucrose (24 h), 0.5 M sucrose (24 h), 0.25 M sucrose (48 h) and 0.15 M sucrose (24 h)] and cultivated in half strength Murashige & Skoog medium (1962) with the addition of 2 g/L activated charcoal. Sixty four percent of seeds survived and developed into acclimatized plants after being cryopreserved. In this work, the encapsulation-dehydration technique was employed for first time in Cyrtopodium hatschbachii. 相似文献
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BÁRBARA C TRANJAN ADRIANO G CRUZ EDUARDO H M WALTER JOSE A F FARIA HELENA M A BOLINI MIRIAM R L MOURA LUCIA M J CARVALHO 《International Journal of Dairy Technology》2009,62(3):438-443
Beverages made from goat cheese whey, flavoured with strawberry and peach pulp, were processed and submitted to physicochemical analysis and affective tests. The beverages exhibited similar values with respect to all the analyses of the proximate composition and little variation in pH and titratable acidity during refrigerated storage. They also showed low caloric value. For colour, aroma and consistency acceptability, there was no significant difference ( P > 0.05) among peach and strawberry flavoured samples. The flavour acceptability was higher for the strawberry beverage than for the peach one ( P = 0.05). A positive purchase intent for strawberry flavoured beverage was reported by 76% of the consumers, while 50% affirmed a similar intention for the peach-flavoured product. The beverages produced showed potential for commercialization, serving as an additional alternative product derived from goat milk, with minimal additional cost to the dairy plant. 相似文献
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CELIA CONESA CARMEN ROTA EDUARDO CASTILLO MARÍA D PÉREZ MIGUEL CALVO LOURDES SÁNCHEZ 《International Journal of Dairy Technology》2010,63(2):209-215
The effect of different heat treatments on the antimicrobial activity of bovine lactoferrin against Escherichia coli O157:H7, Salmonella enteritidis and Listeria monocytogenes has been studied. We have observed that the heat treatments lower than 85°C for 10 min did not affect the antibacterial activity of the protein. Hydrolysates of bovine lactoferrin were found to be more active than the native protein against the three pathogens. Moreover, the antibacterial effect of bovine lactoferrin was also assayed in milk and whey, and although we found a reduction in the number of viable cells, this reduction was lower than in culture media. 相似文献
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Proteolytic activity among psychrotrophic bacteria isolated from refrigerated raw milk 总被引:1,自引:0,他引:1
MARIA F B L NÖRNBERG ROSANE S C FRIEDRICH RITA D N WEISS EDUARDO C TONDO ADRIANO BRANDELLI 《International Journal of Dairy Technology》2010,63(1):41-46
Psychrotrophic bacteria were isolated from refrigerated raw milk from a processing plant in Southern Brazil. Psychrotrophic counts were between 4.9 and 7.8 log cfu/mL, and 5.3 to 7.2 log cfu/mL, for samples collected at the truck and the milk storage silo, respectively. Among the bacterial isolates, 90% were Gram-negative. Most strains presented low proteolytic activity, but strains of Burkholderia cepacia, Klebsiella oxytoca and Aeromonas sp. showed higher than 20 U/mL on azocasein as substrate. Crude proteases from selected strains were resistant to conventional heat treatments and caused coagulation of UHT milk after 5 days storage at room temperature. 相似文献
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CHEILA MINÉIA DANIEL DE PAULA ROBERTA FOGLIATTO MARIOT EDUARDO CESAR TONDO 《Journal of Food Safety》2005,25(1):43-57
Salmonella enteritidis was cultivated in egg yolks and submitted to boiling and frying methods commonly used in domestic conditions in the south of Brazil. The results have demonstrated a rapid growth of the microorganism reaching counts of 9.0 log10at 168 h. When contaminated shell eggs were placed in water and slowly heated, a population of approximately 7.0 log10was completely inactivated after boiling for 1 min. However, in eggs placed directly in boiling water, the reduction was only 1.35 log10after 1 min, and the entire population was eliminated after 3 min. A reduction of approximately 2.78 log10was observed after frying for 1.5, 2.0 and 2.5 min. Even though the solidification of yolk has been pointed out as an indicator of S. enteritidis elimination in egg yolks, attention should be given to frying procedures, as considerable high levels of this microorganism could be recovered even from solidified yolks. 相似文献