100 research outputs found
Novel highly emissive non proteinogenic amino acids : synthesis of 1,3,4-thiadiazolyl asparagines and evaluation as fluorimetric chemosensors for biologically relevant transition metal cations
Highly emissive heterocyclic asparagine derivatives bearing a 1,3,4-thiadiazolyl unit at the side chain, functionalised with electron donor or acceptor groups, were synthesised and evaluated as amino acid based fluorimetric chemosensors for metal cations such as Cu2+, Zn2+, Co2+ and Ni2+. The results suggest that there is a strong interaction through the donor heteroatoms at the side chain of the various asparagine derivatives, with high sensitivity towards Cu2+ in a ligand-metal complex with 1:2 stoichiometry. Association constants and detection limits for Cu2+ were calculated. The photophysical and metal ion sensing properties of these asparagine derivatives confirm their potential as fluorimetric chemosensors and suggest that they can be suitable for incorporation into chemosensory peptidic frameworks.Fundação para a Ciência e a Tecnologia (FCT) - PTDC/QUI/66250/2006 (FCOMP-01-0124-FEDER-007428
Sucrose in the concentrated solution or the supercooled “state” : a review of caramelisation reactions and physical behaviour
Sucrose is probably one of the most studied molecules by food scientists, since it plays an important role as an ingredient or preserving agent in many formulations and technological processes. When sucrose is present in a product with a concentration near or greater than the saturation point—i.e. in the supercooled state—it possesses high potentialities for the food industry in areas as different as pastry industry, dairy and frozen desserts or films and coatings production. This paper presents a review on critical issues and research on highly concentrated sucrose solutions—mainly, on sucrose thermal degradation and relaxation behaviour in such solutions. The reviewed works allow identifying several issues with great potential for contributing to significant advances in Food Science and Technology.Authors are grateful for the valuable discussions with Teresa S. Brandao and Rosiane Lopes da Cunha during this research. Author M. A. C. Quintas acknowledges the financial support of her research by FCT grant SFRH/BPD/41715/2007
Modelagem matemática da secagem convectiva com radiação infravermelha de grãos de Moringa oleifera
Characteristics of Different Systems for the Solar Drying of Crops
Solar dryers are used to enable the preservation of agricultural crops, food processing industries for
dehydration of fruits and vegetables, fish and meat drying, dairy industries for production of milk powder,
seasoning of wood and timber, textile industries for drying of textile materials. The fundamental concepts and
contexts of their use to dry crops is discussed in the chapter. It is shown that solar drying is the outcome of
complex interactions particular between the intensity and duration of solar energy, the prevailing ambient
relative humidity and temperature, the characteristics of the particular crop and its pre-preparation and the
design and operation of the solar dryer
Avaliação de modelos matemáticos na descrição das curvas de secagem por convecção de Pectis brevipedunculata (Gardner) Sch. Bip.
Recobrimentos à base de carboximetilcelulose e dextrina em mangas 'Tommy Atkins' armazenada sob refrigeração
Comparison of transverse and modified subtrochanteric femoral shortening osteotomy in total hip arthroplasty for developmental dysplasia of hip: a meta-analysis
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