排序方式: 共有24条查询结果,搜索用时 15 毫秒
1.
Calderón de la Barca AM Wall Medrano A Jara Marini M González Córdova AF Ruíz Salazar A 《Archivos latinoamericanos de nutrición》2000,50(1):26-34
Production of new protein-based products for special nutrition such as hypoallergenic infant formulas, fortified beverages and nutraceutics, require ideal ingredients. Protein ingredients were developed by enzymatic hydrolysis and methionine synthesis of soy protein. Hydrolysis was done at 4% (w/v) using porcine pancreatic enzymes (4% w/w), 50 degrees C, 6 h and pH 8. After drying powder was resuspended (20% w/v) and incubated with 7.6% (w/w) methionine methyl-ester, 1% (w/w) chymotrypsin and 3 M glycerol, 37 degrees C, 3 h and pH 7. Hydrolysates were fractionated by ultrafiltration (UF) before and after enrichment (E): FI > 10, 10 > FII > 3 and 3 > FIII > 1 kDa. Functional properties, amino acid content, anti-physiological factor activities and antigenicity were assayed for all the UF fractions and the soybean meal. Protein quality bioassay and sensorial test of an non-enriched fraction and an enriched fraction were performed. Functional properties were positively modified by hydrolysis and synthesis by using a minimum time and methionine added for the last reaction. After UF all the fractions under 10 kDa showed 100% solubility (pH 4 and 7), good clarity, acceptable foam capacity and negligible antigenicity and antiphysiological activities. Additionally, methionine enrichment enhanced their nutritional value, upgrading sulfur amino acid requirements for infants and adults. Because functionality and nutritional value FIII-E could be used for hypoallergenic infant formulas, FII-E for fortified soluble formulas and nutraceutics and FI-E for a semi-solid baby food. 相似文献
2.
Edgar I. Jiménez‐Ruiz Ana M. Calderón de la Barca Rogerio R. Sotelo‐Mundo Guillermo E. Arteaga‐Mackinney Martin Valenzuela‐Melendez E. Aida Peña‐Ramos 《Journal of food science》2013,78(8):C1152-C1158
Soy protein isolate (SPI) was hydrolyzed with Flavourzyme® (SHF) or chymotrypsin (SHC). Hydrolysates were sequencially fractionated by ultrafiltration using different membrane pore sizes (50, 10, and 3 kDa). The antioxidant ability of each hydrolysate protein fraction was tested in a liposome oxidizing system and their free radical scavenging activity (FRSA) was evaluated with the DPPH method (diphenylpicrilhydrazine radical). Molecular weight (MW) distribution, solubility, surface hydrophobicity, and amino acid composition of each SPI hydrolysate fraction were measured and their effect on antioxidant and scavenging activities was established by multivariate correlation. The most active ultrafiltrated peptide fractions (P < 0.05), from SHF and SHC, had of MW of <3 kDa (F3 and C3, respectively). These fractions decreased liposome oxidation by 83.2% and 84.5%, respectively, and also showed the highest FRSA (F3: 21.3% and C3: 24.4%). In addition to molecular size, the antioxidant activity and FRSA of soy protein fractions were related to their amino acid composition, especially to an increased content of Phe and a lowered content of Lys. Also, hydrophobicity of ultrafiltrated peptide fractions was an important characteristic (P < 0.001) associated with their ability to trap free radicals. Ultrafiltered peptide fractions with low MW have a high potential to be used as natural alternatives to prevent lipid oxidation in foods. 相似文献
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4.
Benedetto Bozzini Amilcare Barca Francesco Bogani Marco Boniardi Paolo Carlino Claudio Mele Tiziano Verri Alessandro Romano 《Journal of materials science. Materials in medicine》2014,25(6):1425-1434
In this paper we describe the one-pot fabrication of hydroxyapatite (HA)-heparin composites by electrodeposition onto Ti substrates and their characterisation in terms of structure, morphology, heparin content and bioactivity. HA coatings are well known and widely applied osteointegration enhancers, but post-implant healing rate in dental applications is still suboptimal: e.g. coagulation control plays a key role and the incorporation of an anticoagulant is considered a highly desirable option. In this study, we have developed an improved, simple and robust growth procedure for single-phase, pure HA-heparin films of thickness 1/3 μm. HA-heparin, forming nanowires, has the ideal morphology for bone mineralisation. Staining assays revealed homogeneous incorporation of sizable amounts of heparin in the composite films. The bioactivities of the HA and HA-heparin coatings on Ti were compared by HeLa cell proliferation/viability tests and found to be enhanced by the presence of the anticoagulant. 相似文献
5.
M Sargiacomo P Onori E Bravo A Franchitto A Cantafora S Barca C Peschle E Gaudio 《Canadian Metallurgical Quarterly》1998,28(3):480-490
BACKGROUND/AIMS: The present study describes an embryonic-fetal liver culture system which allows morphogenetic interactions consistent with the development of the hepatocellular function. METHODS: Intact livers from 8-12-week embryos were soaked in an extracellular matrix at 4 degrees C and gently dissociated without any enzymatic treatment. The resulting spherical hepatic units were cultured in a chemically defined serum-free medium and seeded into an extracellular matrix layer. Adherent three-dimensional tissue specimens were examined at various times by light and electron microscopy to evaluate the maintenance of hepatocyte morphology. RESULTS: The liver cells were viable for over 4 months; erythropoietic burst colonies were detected for longer than 6 weeks. Parallel detection of bile salt production in the medium by high performance liquid chromatography proved liver tissue functionality. Bile salt composition revealed predominance of taurine-conjugates rather than glycine. Maximum bile salt concentration (approximately 3 months) coincided with structural and ultrastructural observations indicating a marked decline in hematopoiesis, well-defined biliary canaliculi and formation of an organ-like structure. CONCLUSIONS: This three-dimensional culture system recapitulates fetal liver development with: (i) initial proliferation of both fetal erythropoietic and hepatic cells and (ii) subsequent shut-off of erythropoiesis and a shift to a more advanced stage of hepatocyte function, such as bile salt secretion. 相似文献
6.
Phan Han Duy Ellis Kirsten Barca Jan Carlo Dorin Alan 《Neural computing & applications》2020,32(2):567-588
Neural Computing and Applications - Parameter settings for nature-inspired optimization algorithms are essential for their effective performance. Evolutionary algorithms and swarm intelligence... 相似文献
7.
A multivariate surface roughness modeling and optimization under conditions of uncertainty 总被引:1,自引:0,他引:1
Luiz Gustavo D. Lopes José Henrique de Freitas Gomes Anderson Paulo de Paiva Luiz Fernando Barca João Roberto Ferreira Pedro Paulo Balestrassi 《Measurement》2013
Correlated responses can be written in terms of principal component scores, but the uncertainty in the original responses will be transferred and will influence the behavior of the regression function. This paper presents a model building strategy that consider the multivariate uncertainty as weighting matrix for the principal components. The main objective is to increase the value of R2 predicted to improve model’s explanation and optimization results. A case study of AISI 52100 hardened steel turning with Wiper tools was performed in a Central Composite Design with three-factors (cutting speed, feed rate and depth of cut) for a set of five correlated metrics (Ra, Ry, Rz, Rq and Rt). Results indicate that different modeling methods conduct approximately to the same predicted responses, nevertheless the response surface to Weighted Principal Component – case b – (WPC1b) presented the highest predictability. 相似文献
8.
J Tato Rodríguez J Lema Grille A Cimadevila García J Abelenda Barca M Blanco Parra A Cimadevila Covelo JM Cameselle Teijeiro 《Canadian Metallurgical Quarterly》1997,21(5):502-507
Accurate nutritional assessment of a child is a complex task involving simultaneous evaluation of several parameters, e.g., nutrient intake and requirement and physical and anthropometric examination, including body composition and biochemical markers. Several of these tests are not readily available in all settings and one may have to rely on simpler tools like thorough clinical assessment, which has a surprisingly high degree of sensitivity. 相似文献
9.
We have obtained superconducting Bi2Sr2CaCu2O8+x ceramic compounds with a grain structure that consists of needle-like particles of about 1.5 mm in length and 100 μm in diameter,
which seem to be formed by flake-like small grains. The Bi(2212) compound has been prepared following the polymer solution
synthesis method. The thermal treatment used is a simplified version of the melt-textured growth process (MTG), with the sample
placed in a zone of a simple tube furnace where the temperature gradient was about 15°C/cm. We have performed scanning electron
microscopy (SEM) observations on the samples, before and after thermal treatment. In addition, we have measured the ac susceptibility
of both samples to confirm their superconducting nature and critical temperatures of about 91 K. 相似文献
10.
Barberio M Barca D Barone P Pingitore V Bonanno A 《Journal of nanoscience and nanotechnology》2011,11(10):9196-9201
Luminescence spectra obtained by electron bombardment of carbon nanotubes bundles show an UV signal centered at about 380 nm. We show that these transitions are extrinsic to nanotubes, in the sense that they are not linked to any carbon compound or structure, but are caused by the residual catalyst material used in the growth process. A possible role of such luminescence attributable to impurities is also discussed. In fact our luminescence measurements, in association with laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and X-ray photoelectron spectroscopy (XPS), permit us to assign these spectral bands to Zn and Al oxides. Our conclusions, supported by data in literature, and the comparison with the quantitative results obtained by LA-ICP-MS spectrometry (which detects ppm) allows us to define cathode-luminescence analysis as a good technique to control cleanness and purity of carbon nanotube samples. 相似文献