Benders'dictionary of nutrition and food technology

471thermophiles Bacteria that prefer temperatures above 55 °C andcan tolerate temperatures up to 75–80 °C. Extreme thermophilescan live in boiling water, and have been isolated from hotsprings.thiamin See vitamin b 1 .thiaminases Enzymes that cleave thiamin (vitamin b 1 ). ThiaminaseI (EC 2.5.1.2) is found in freshwater fish, ferns and somebacteria; it catalyses an exchange reaction between the thiazolering and a variety of bases. Thiaminase II (EC 3.5.99.2) occurs ina small number of micro-organisms; it catalyses hydrolysis of themethylene–thiazole bond, releasing toxopyrimidine.thiazoles Derivatives of five-membered heterocyclic compoundscontaining both N and S in the ring (C 3 H 3 NS) that impart green,roasted or nutty flavours to foods. May be naturally present infoods or formed by the maillard reaction.thiazolindinediones Group of oral hypoglycaemic agents usedin treatment of type II diabetes mellitus; they increase insulinsensitivity of tissues, and activate the PPARγ receptor andrepress the synthesis of 11β-hydroxysteroid dehydrogenase inadipocytes, so reducing the formation of cortisol in adiposetissue.thiobarbituric acid reactive substances See tbars.thiobarbituric acid (TBA) value See tba value.thiobendazole Drug used to treat intestinal infestation withSTRONGYLOIDES spp., and, as an antifungal agent, for surface treatmentof bananas.thiochrome Fluorescent product of the oxidation of thiamin(vitamin b 1 ) in alkaline solution; the basis of an assay of thevitamin.thioctic acid See lipoic acid.thiophenes Derivatives of five-membered heterocyclic compounds(C 4 H 4 S), sulphur analogues of furans that impartpungent or sweet flavours to foods.thirst See water balance.thixotropic A fluid whose structure breaks down with continuedshear stress, so that viscosity decreases, as is the case with mostcreams.See also dilatant; pseudoplastic; rheopectic.thoracic duct One of two main trunks of the lymphatic system;receives lymph from the legs and lower abdomen, and drains intothe left innominate vein. The main point of entry of chylomicronsinto the bloodstream.threonine An essential amino acid, abbr Thr (T), M r 119.1, pK a2.09, 9.10, codons ACNu.