“L-Glutamate elicits the umami taste sensation, now recogn


“L-Glutamate elicits the umami taste sensation, now recognized as a fifth distinct taste quality. A characteristic feature of umami taste is its potentiation by 5′-ribonucleotides such as guanosine-5′-monophosphate and inosine 5′-monophosphate, which also elicit the umami taste on their own. Recent data suggest that multiple G protein-coupled receptors contribute to umami taste. This review will focus on events downstream of the umami taste receptors. Ligand

binding leads to G beta gamma activation of phospholipase C beta 2, which produces the second messengers inositol trisphosphate and diacylglycerol. Inositol trisphosphate binds to the type III inositol trisphosphate receptor, which causes the release of Ca(2+) from intracellular

stores and Ca(2+)-dependent activation of a monovalent-selective cation channel, TRPM5. TRPM5 is believed to depolarize taste GSK621 nmr cells, which leads to the release of ATP, which activates ionotropic purinergic receptors on gustatory afferent nerve fibers. This model is supported by knockout of the relevant signaling effectors as well as physiologic studies of isolated taste cells. Concomitant with the molecular studies, physiologic studies show that L-glutamate elicits increases in intracellular Ca(2+) in isolated taste cells and that the source of the Ca(2+) is release from intracellular stores. Both Ga gustducin and Ga transducin are involved in umami signaling, because the knockout NVP-BSK805 manufacturer of either subunit compromises responses to umami stimuli. Both alpha-gustducin and alpha-transducin activate phosphodiesterases to decrease intracellular cAMP. The target of cAMP in umami transduction is not known, but membrane-permeant analogs of cAMP antagonize electrophysiologic responses to umami stimuli in isolated taste cells, which suggests that cAMP may have a modulatory role in umami signaling. Am J Clin Nutr 2009; 90 (suppl): 753S-5S.”
“Biobased nanocomposites were manufactured through the melt intercalation of nanoclays and starch esters synthesized at the Fraunhofer Institute for Applied Polymer

Research (TAP) from high amylose starch. Starch acetates (SAs) and starch propionates (SPs) were tested in combination with glycerol triacetate (triacetin) as a plasticizer for concentrations up to 30 and 20 wt %, respectively, see more with different types of organomodified and unmodified montmorillonites (MMTs). The mechanical properties of injection-molded test bars were determined by a tensile experiment giving the strength, modulus, and elongation of the composites. X-ray diffraction (XRD) analysis and transmission electron microscopy (TEM) were used to study clay dispersion and intercalation/exfoliation. Dynamic mechanical analysis was used to track the temperature dependence of the storage modulus and tan delta behavior of the starch/clay hybrid. Because they were the best performing compositions, SP with 5 wt % plasticizer and SA with 20 wt % plasticizer were filled with 5 wt % nanoclay.

Comments are closed.