Benders'dictionary of nutrition and food technology

470theobromine 3,7-Dimethylxanthine, an alkaloid found in cocoa,chemically related to caffeine, and with similar effects.theophylline 1,3-Dimethylxanthine, an alkaloid found in tea,chemically related to caffeine, and with similar effects.therapeutic diets Those formulated to treat disease or metabolicdisorders.therapeutic index Ratio of the dose of a drug that causes tissueor cell damage to that required to have a therapeutic effect.therm Obsolete unit of heat = 1.055 × 10 8 J.thermal centre The point in a food that heats or cools most slowly.thermal conductivity The rate at which heat moves through asubstance.thermal death time (TDT) Measure of heat resistance of anorganism, enzyme or chemical component at a particular temperature,usually 121 °C. Also known as F-value.thermal diffusivity The ratio of thermal conductivity of a materialto its (specific heat capacity × density).thermal efficiency In drying of foods, the ratio of heat used inevaporation to total heat supplied in the process.Thermamyl TM Heat-stable α-amylase from Bacillus licheniformis,active up to 100 °C; used in manufacture of glucose syrupfrom starch.thermic effect of food See diet-induced thermogenesis.thermisation Heat treatment to reduce the number of microorganisms;less severe than pasteurisation; used e.g. in cheesemaking.thermoduric Bacteria that are heat resistant but not thermophilic(see thermophiles), i.e. they survive, but do not develop, at pasteurisationtemperatures. Usually not pathogens but indicativeof unsanitary conditions.thermogenesis Increased heat production by the body, eitherto maintain body temperature (by either shivering or nonshiveringthermogenesis) or in response to food intake (dietinducedthermogenesis).See also adipose tissue, brown; uncoupling proteins.thermogenic drugs Compounds that stimulate body heat output,and thus of potential interest in ‘slimming’.thermogenin See uncoupling proteins.thermography Technique for measuring and recording heatoutput by regions of the body, using a film or detector sensitiveto infrared radiation.thermopeeling A method of peeling tough-skinned fruits inwhich the fruit is rapidly passed through an electric furnace atabout 900 °C, then sprayed with water.