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101.
C. Vidal-Valverde Marin Prodanov Isabel Sierra 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1997,205(6):464-469
Lentils (Lens culinaris, var. vulgaris cultivar Magda-20) were naturally fermented for 96 h at different lentil flour concentrations (79, 150 and 221 g/l) and temperatures
(28, 35 and 42°C). During fermentation, samples were taken at 24-h intervals and the changes in thiamin (vitamin B1), riboflavin (vitamin B2) and total and available niacin (vitamin B3) were investigated. Preparation of the lentil flour suspension to be fermented (i.e. the process of mixing the flour and
sterilized tap water) caused an increase of the available niacin content in all batches, while changes in thiamin and riboflavin
content were related to the conditions in which the preparation of the suspensions was carried out. The whole natural fermentation
process (from the raw state to after 96 h of fermentation), either did not affect or produced a slight decrease in the thiamin
content of lentils. In contrast, riboflavin, available niacin and total niacin contents increased throughout the 96 h period,
which ended with a 35 – 82% increase of riboflavin, a 24 – 91% increase of available niacin and a 20 – 58% increase of total
niacin. The temperature during the fermentation procedure had significant effect on the levels of thiamin and riboflavin in
fermented lentils. To obtain lentil flours with an improved amount of riboflavin and available niacin with a minimum loss
of thiamin, the natural fermentation of lentils should be carried out for 96 h at 42°C and with a lentil flour concentration
of 221 g/l.
Received: 21 February 1997 相似文献
102.
Olha Khymenets Jesús Joglar Pere Claps Teodor Parella María‐Isabel Covas Rafael de la Torre 《Advanced Synthesis \u0026amp; Catalysis》2006,348(15):2155-2162
The biocatalytic synthesis and purification of O‐β‐D ‐monoglucuronide conjugates of hydroxytyrosol, tyrosol, homovanillic alcohol, and 3‐(4′‐hydroxyphenyl)propanol, using porcine liver microsomes, are described here. The glucuronides were synthesized, analyzed and separated by HPLC‐UV, identified by HPLC‐MS, and their structures unequivocally established by NMR techniques. The outcome of the glucuronidation reaction depends on the structure of the phenolic compounds. Thus, the glucuronidation of hydroxytyrosol, biocatalyzed with porcine liver microsomes, proceeded exclusively on the phenolic hydroxy groups. The regioselectivity was similar to that observed for human and rat liver microsomes, the 4′‐hydroxy position being more favorable than the 3′‐hydroxy one. In the case of tyrosol, homovanillic alcohol, and hydroxyphenylpropanol, two products were formed during microsomal glucuronidation: a major one, the phenolic O‐β‐D ‐glucuronidated derivative and, a minor one, the O‐β‐D ‐glucuronidated aliphatic alcohol. 相似文献
103.
Raffaele Sacchi Isabel Medina Santiago P. Aubourg Francesco Addeo Livio Paolillo 《Journal of the American Oil Chemists' Society》1993,70(3):225-228
Based on proton nuclear magnetic resonance (1H-NMR) spectroscopy, a rapid and structure-specific method for the determination of ω-3 polyunsaturated fatty acids (PUFAs)
in fish lipids is presented. The different chemical shift observed for the methyl resonance of ω-3 PUFAs (δ=0.95 ppm) with
respect to the methyl resonance of all other fatty acids (δ=0.86 ppm) has provided the possibility of proposing a new and
rapid method for the determination of ω-3 PUFA content. Twenty-four fish lipid samples (raw, cooked and canned albacore tuna)
produced results that showed good agreement between1H-NMR analysis and gas chromatographic determination. Raw and cooked samples showed significantly higher levels of ω-3 PUFA
than canned tuna. 相似文献
104.
Burns P Vinderola G Reinheimer J Cuesta I de Los Reyes-Gavilán CG Ruas-Madiedo P 《The Journal of dairy research》2011,78(3):357-364
The capacity of lactic acid bacteria to produce exopolysaccharides (EPS) conferring microorganisms a ropy phenotype could be an interesting feature from a technological point of view. Progressive adaptation to bile salts might render some lactobacilli able to overcome physiological gut barriers but could also modify functional properties of the strain, including the production of EPS. In this work some technological properties and the survival ability in simulated gastrointestinal conditions of Lactobacillus delbrueckii subsp. lactis 193, and Lb. delbrueckii subsp. lactis 193+, a strain with stable bile-resistant phenotype derived thereof, were characterized in milk in order to know whether the acquisition of resistance to bile could modify some characteristics of the microorganism. Both strains were able to grow and acidify milk similarly; however the production of ethanol increased at the expense of the aroma compound acetaldehyde in milk fermented by the strain 193+, with respect to milk fermented by the strain 193. Both microorganisms produced a heteropolysaccharide composed of glucose and galactose, and were able to increase the viscosity of fermented milks. In spite of the higher production yield of EPS by the bile-resistant strain 193+, it displayed a lower ability to increase viscosity than Lb. delbrueckii subsp. lactis 193. Milk increased survival in simulated gastric juice; the presence of bile improved adhesion to the intestinal cell line HT29-MTX in both strains. However, the acquisition of a stable resistance phenotype did not improve survival in simulated gastric and intestinal conditions or the adhesion to the intestinal cell line HT29-MTX. Thus, Lb. delbrueckii subsp. lactis 193 presents suitable technological properties for the manufacture of fermented dairy products; the acquisition of a stable bile-resistant phenotype modified some properties of the microorganism. This suggests that the possible use of bile-resistant derivative strains should be carefully evaluated in each specific application considering the influence that the acquisition of a stable bile-resistant phenotype could have in survival ability in gastric and intestinal conditions and in technological properties. 相似文献
105.
A comparative study of the phospholipids of white muscle of six of the comercially utilized tuna species, including quantitative
analyses of phospholipid classes and studies of the acyl composition of the major components. Plasmalogen compounds also were
identified and quantified. Choline and ethanolamine glycerophospholipids were the most abundant classes in all the samples,
as well as the only molecules containing plasmalogens (16∶0, 18∶0, and 18∶1 alkenyl ether chains). The patterns of fatty acid
distribution within each of the phospholipid classes showed general similarities in the species analyzed. However, ratios
between certain saturated and polyunsaturated fatty acids in different phospholipid classes showed remarkable diffences. The
high content of n−3 polyunsaturated fatty acids in the principal phospholipids, such as the plasmalogens, and taking into
account the fatty acids possible importance in human nutrition, indicates that the white muscle of tuna species may be a potentially
important dietary item. 相似文献
106.
107.
Ana Maria Ramos Joaquim Vital Isabel F. Silva Humberto Valente Pedro T. Gomes 《Catalysis Letters》1998,51(1-2):117-119
The homopolymerisation of styrene is studied in the presence of Y, USY and beta zeolites. High molecular weight polymers, in the range 0.7 × 106–1 × 106, are obtained in good yields. The activity of zeolite beta is only slightly increased by calcination of the as-synthesised material, pointing to an important role of the zeolite outer surface. The influence of the catalyst acidity upon the polymer molecular weight is evaluated by the use of dealuminated zeolites. This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
108.
Luiz F.G. Setz Isabel Santacruz M. Teresa Colomer Sonia R.H. Mello-Castanho Rodrigo Moreno 《Journal of the European Ceramic Society》2010,30(14):2897-2903
Lanthanum chromite (LaCrO3) is currently the most widely studied material as interconnector layers for solid oxide fuel cells (SOFC). The complexity of microstructures and geometries of SOFC devices, which are usually built-up by lamination of the different constitutive layers, make it necessary a precise control of processing parameters to achieve the desired combination of properties. Much effort has been devoted to the processing of electrodes and electrolytes but the other layers, such as that of interconnecting material, have received scarce attention. This work deals with the preparation and optimisation of the rheological behaviour of concentrated suspensions of Sr- and Co-doped LaCrO3 and the subsequent tape casting to produce homogeneous thin sheets to be used in the SOFC stack.The starting powder was produced by combustion synthesis from the corresponding nitrates and urea as a fuel, and had a final composition of La0.80Sr0.20Cr0.92Co0.08O3. These powders were dispersed in ethanol with commercial copolymers (Hypermer, KD6) to solids loading of up to 58 wt%. The binding system (BS) consisted of a mixture of a binder, polyvinyl butyral-co-vinyl alcohol-co-vinyl acetate (PVA-PVAc), and two plasticizers, polyethyleneglycol (PEG400) and benzylbutylphthalate (BBP). The effect of the binding system content and the binder-to-plasticizer ratio on the tape casting performance and the characteristics of the green and the sintered tapes, were studied, as well as the influence of the casting parameters (casting speed and blades height). 相似文献
109.
Ana Belén Pérez Marín María Isabel Aguilar Juan Francisco Ortuño Víctor Francisco Meseguer José Sáez Mercedes Lloréns 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2010,85(10):1310-1318
BACKGROUND: This research provides new insights into the biosorption of zinc on a waste product from the orange juice industry. Optimal operating conditions maximizing percentage zinc removal were determined in batch and fixed‐bed systems. Biomass was characterized by FTIR spectroscopy and by major cation content in order to better understand the biosorpion mechanism. Zn‐loaded orange waste was proposed to be used as an alternative fuel in cement kilns. RESULTS: Sorption capacity was strongly affected by biosorbent dose and solution pH, and was not strongly sensitive to particle size under the experimental conditions studied. Equilibrium data were successfully described by a Langmuir model and sorption kinetic data were adequately modelled with the pseudo‐second‐order and Elovich rate equation. The biomass was found to possess high sorption capacity (qmax = 0.664 mmol g?1) and biosorption equilibrium was established in less than 3 h. Experimental breakthrough curves were adequately fitted to the Thomas model and the dose–response model, obtaining sorption capacities in continuous assays higher than those found in batch mode. Characterization of the biomass suggested the possible contribution of carboxyl and hydroxyl groups of biomass in Zn2+ biosorption and it also highlighted the important role of light metal ions in a possible ion‐exchange mechanism. CONCLUSIONS: Orange waste could be used as an effective and low‐cost alternative biosorbent material for zinc removal from aqueous solution. Copyright © 2010 Society of Chemical Industry 相似文献
110.
Carlos Alonso-Moreno José Sancho Fernando Carrillo-Hermosilla Antonio Otero Antonio Antiñolo Isabel López-Solera 《Inorganic chemistry communications》2009,12(2):184-186
Rac and meso ansa-zirconocenes [Zr{1-Me2Si(3-R-(η5-C9H5))(3-R′-(η5-C9H5))}Cl2] (R = Et, R′ = H; R = Pr, R′ = H; and R = Et, R′ = Pr) 4–9 have been prepared by the reaction of ZrCl4 with the corresponding dilithiated derivatives from the ligands {1-Me2Si(3-R-(η5-C9H5))(3-R′-(η5-C9H5))} (R = Et, R′ = H 1; R = Pr, R′ = H 2; and R = Et, R′ = Pr 3) in diethyl ether/toluene at ?78 °C. The molecular structure of rac [Zr{1-Me2Si(3-Et-(η5-C9H5))(3-Pr-(η5-C9H5))}Cl2] 8 has been determined by single crystal X-ray diffraction studies, which show a pseudotetrahedral environment formed by the two chlorine ligands and two η5-coordinated indenyl ligands. The activity in homogeneous and heterogeneous polymerization is compared and discussed. 相似文献