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Different pH Ranges (different + ph_range)
Selected AbstractsEFFECT OF VARIETAL DIFFERENCES AND POLISHING OF RICE ON QUALITY PARAMETERS OF IDLIJOURNAL OF SENSORY STUDIES, Issue 5 2005CHANDINI S. KUMAR ABSTRACT The effect of varietal differences and polishing of rice on quality parameters of "idli," an Indian fermented product, were studied. In addition, the functional properties of decorticated (whole and split) black gram (Phaseolus mungo Roxb.), were also determined. Two varieties of raw rice, "Jaya" and "Minilong," and one variety of parboiled rice "Ponni" with two degrees of polishing (high and low) were selected. Idlis were prepared following standard procedures. Variations were observed in water and fat absorption capacities of two black gram samples. Emulsification capacity ranged from 102 to 110 mL/100 g. Foam capacities at different pH range were similar, but foam stability differed as a function of time. The pH of the fermented batter was between 4.1 and 4.8. Rice with a lesser degree of polishing fermented better with higher batter volume and microbial count, lesser shear value and gave softer idlis. However, sensory analysis revealed that idlis prepared with low-polish rice scored significantly lower for appearance and color quality compared with products prepared with high-polish rice. Significant differences were observed in the quality of flavor of all products. It can be concluded that the quality characteristics of Idli were influenced by the variety of rice and the degree of polishing, but the two types of black gram used, whole and split, had no effect. [source] Titanium dioxide nanoparticles-coated column for capillary electrochromatographic separation of oligopeptidesELECTROPHORESIS, Issue 21 2005Yi-Ling Hsieh Abstract A novel column made through the condensation reaction of TiO2 nanoparticles (TiO2,NPs) with silanol groups of the fused-silica capillary is described. EOF measurements under various buffer constitutions were used to monitor the completion of reactions. The results indicated that the EOF was dependent on the interactions between buffers and the bonded TiO2,NPs. With formate/Tris buffer, EOF reversal at pH below,5 and cathodic EOF at pH above,5 were indicated. The pI of the bonded TiO2,NPs was found at ,ph,5. Only cathodic EOF was illustrated by substituting the mobile phase with either glutamate or phosphate buffer. It was elucidated that both glutamate and phosphate buffer yield a negative charge layer on the surface of TiO2,NPs attributable to the formation of a titanium complex. The CEC performance of the column was tested with angiotensin-type oligopeptides. Some parameters that would affect the retention behavior were investigated. The interactions between the bonded phases and the analytes were explicated by epitomized acid,base functional groups of the oligopepetides and the speciation of the surface oxide in different pH ranges. The average separation efficiencies of 3.1×104,plates/m is readily achieved with a column of 70,cm (50,cm)×50,,m,ID under an applied voltage of 15,kV, phosphate buffer (pH,6.0, 40,mM), and UV detection at 214,nm. [source] Photophysical and Photochemical Studies of PyridoxamineHELVETICA CHIMICA ACTA, Issue 10 2003Claudio Bueno The absorption and fluorescence emission of pyridoxamine were studied as function of pH and solvent properties. In the ground state, pyridoxamine exhibits different protonated forms in the range of pH,1.5,12. Fluorescence studies showed that the same species exist at the lowest singlet excited state but at different pH ranges. The phenol group is by ca. 8,units more acidic in the excited state than in the ground state. On the other hand, the pyridine N-atom is slightly more basic in the lowest excited state than in the ground state. Excitation spectra and emission decays in the pH range of 8,10 indicate the protonation of the pyridine N-atom by proton transfer from the amine group, in the ground and singlet excited states. Spectroscopic studies in different solvents showed that pyridoxamine in the ground or excited states exhibits intramolecular proton transfer from the pyridine N-atom to the phenol group, which is more favorable in solvents of low hydrogen-bonding capacity. The cationic form with the protonated phenolic group, which emits at shorter wavelength, is the dominant species in nonprotic solvents, but, in strong proton-donor solvents, both forms exist. The fluorescence spectra of these species exhibit blue shift in protic solvents. These shifts are well-correlated with the polarity and the H-donor ability of the solvent. [source] Establishment of a PF2D-MS/MS platform for rapid profiling and semiquantitative analysis of membrane protein biomarkersPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 11 2008Hyoung-Joo Lee Abstract Current proteome profiling techniques have identified relatively few mammalian membrane proteins despite their numerous important functions. To establish a standard throughput-potential profiling platform for membrane proteins, Triton X-100-solubilized rat liver microsomal proteins were separated on a 2-D separation system (2-D liquid phase fractionation (PF2D)) in two different pH ranges (4.0,8.5 and 7.0,10.5). This system produced 182 proteins with more than two transmembrane domain (TMD), including 16,TMDs with high confidence. Comparative 2-D liquid maps with high resolution and reproducibility have been constructed for liver microsome from the phenobarbital (PB) treated rats. PF2D was also found to be useful for the semiquantification of some representative cytochrome P450 family proteins (e.g., cytochrome P450 2B2) that were induced by PB treatment compared with untreated controls. Thus, the combination of both high-detection capacity and rapid preliminary semiquantification in a PF2D platform could become a standard system for the routine analysis of membrane proteins. [source] | ||||||||||