7 documents found, page 1 of 1
Influence of moderate electric fields in β-lactoglobulin thermal unfolding and ...
Rodrigues, Rui M.; Avelar, Zita; Vicente, A. A.; Petersen, Steffen B.; Pereira, Ricardo N.In this study, the effects of moderate electric fields during thermal denaturation of -lactoglobulin were examined through an in situ circular dichroism approach, complemented by intrinsic extrinsic fluorescence analysis. Results have shown that the effects of electric fields in protein unfolding were linearly dependent on the applied electric field intensity (V/cm) and increased by the use of low electric freq...
Multi-step thermally induced transitions of ß-lactoglobulin - an in situ spectr...
Rodrigues, Rui M.; Claro, Bárbara; Bastos, Margarida; Pereira, Ricardo Nuno Correia; Vicente, A. A.; Petersen, Steffen B.An in-situ approach based in multiple spectroscopic techniques and benchmarked with DSC was used to characterise ß-Lg thermally-induced transitions. The methodology applied overcomes previously reported limitations, by ensuring similar experimental conditions in different determinations, non-aggregation conditions and allowing distinguishing between fluorescent variations due to collisional quenching and struct...
Effects of moderate electric fields on cold-set gelation of whey proteins - Fro...
Rodrigues, Rui Miguel Martins; Fasolin, Luiz Henrique; Avelar, Zita; Petersen, Steffen B.; Vicente, A. A.; Pereira, Ricardo Nuno CorreiaWhey protein gelation and final gel properties are dependent of the gel forming solution characteristics (e.g. protein concentration, pH, ionic strength), and physical variables involved in the method used for gel preparation. Ohmic heating (OH) is an emerging technology in food processing and its application in heat-induced gelation of whey proteins has demonstrated its capacity to influence the physicochemica...
Electric field effects on β-lactoglobulin thermal unfolding as a function of pH...
Rodrigues, Rui M.; Vicente, A. A.; Petersen, Steffen B.; Pereira, Ricardo N.The presence of moderate electric fields (MEF) during ohmic heating (OH) treatment of whey protein systems have demonstrated potential to change physicochemical and functional properties, like aggregation rate and extension or viscoelastic behaviour. However, the specific action of MEF upon the molecular structure of proteins, particularly during thermal processing has yet to be clarified. The effects of MEF in...
Determination of thermally-induced conformational slides in β-lactoglobulin pri...
Rodrigues, Rui Miguel Martins; Pereira, Ricardo Nuno Correia; Vicente, A. A.; Petersen, Steffen B.[Excerpt] Introduction: β-lactoglobulin (β-Lg) is the major globular protein in milk and the dominant functional agent in whey and its derivatives ingredients. It is generally recognized that β-Lg undergoes conformational changes above temperatures of 60 °C and unfolds irreversibly after 70 °C. The conformational changes that happen during this process have critical implications in β-Lg functional properties, t...
EGF functionalized polymer-coated gold nanoparticles promote EGF photostability...
Silva, Catarina Oliveira; Petersen, Steffen B.; Reis, Catarina Pinto; Rijo, Patricia; Molpeceres, Jesus; Fernandes, Ana SofiaThe application of functionalized nanocarriers on photothermal therapy for cancer ablation has wide interest. The success of this application depends on the therapeutic efficiency and biocompatibility of the system, but also on the stability and biorecognition of the conjugated protein. This study aims at investigating the hypothesis that EGF functionalized polymer -coated gold nanoparticles promote EGF photost...
Photophysics and photochemistry of horseradish peroxidase A2 upon ultraviolet i...
Neves-Petersen, Maria Teresa; Klitgaard, Soren; Leitao Carvalho, Ana Sofia; Petersen, Steffen B.; de Barros, Maria Raquel Aires; Melo, EduardoDetailed analysis of the effects of ultraviolet (UV) and blue light illumination of horseradish peroxidase A2, a heme-containing enzyme that reduces H2O2 to oxidize organic and inorganic compounds, is presented. The effects of increasing illumination time on the protein's enzymatic activity, Reinheitzahl value,. fluorescence emission,. fluorescence lifetime distribution,. fluorescence mean lifetime, and heme ab...