Benders'dictionary of nutrition and food technology

235through a solid material) and convection (transfer by movementof molecules through a fluid as a result of lower density at highertemperatures).heat transfer, steady-state Heating or cooling when there is nochange in temperature at any specific location.heat transfer, unsteady-state Heating or cooling where the temperatureof the food and/or the heating or cooling medium areconstantly changing.hedonic scale Term used in tasting panels where the judges indicatethe extent of their like or dislike for the food.heel-prick test See guthrie test.Hegsted score Method of expressing the lipid content of a diet,calculated as 2.16 × % energy from saturated fat −1.65 × %energy from polyunsaturated fat −0.0677 × mg cholesterol. Seealso Keys score.Helicobacter pylori Bacterium commonly infecting the gastricmucosa. The underlying cause of ulcers, and implicated inthe development of gastric cancer. Formerly classified asCAMPYLOBACTER.helminths Various parasitic worms, including flukes, tapewormsand nematodes.hemicelluloses Complex carbohydrates included as dietaryfibre, composed of polyuronic acids combined with xylose,glucose, mannose and arabinose. Found together with celluloseand lignin in plant cell walls; most gums and mucilages arehemicelluloses.hemoglobin American spelling of haemoglobin; similarly,hematin = haematin, heme = haem, hemosiderin = haemosiderin.hemp seed Fruits of Cannabis sativa, eaten toasted in China, as acondiment in Japan; the oil is added to salad dressings and dips,but is not suitable for cooking. The seed contains little or nocannabinoids.HEPA filter See high efficiency particulate air filter.heparin Complex carbohydrate (glycosaminoglycan) from mastcells in liver, lung, muscle, heart and blood which prevents bloodcoagulation by activating antithrombin III, and so inhibiting theconversion of prothrombin to thrombin. In vivo cleared rapidlyfrom the bloodstream, but in vitro 10 mg prevents the coagulationof 100 mL of blood.hepatic encephalopathy Impairment of brain function, leading tocoma, as a result of liver disease.hepatitis Inflammatory liver disease, characterised by jaundice,abdominal pain and anorexia. May be due to bacterial or viralinfection, alcohol abuse or various toxins. Treatment is usuallyconservative, with a very low fat diet (secretion of bile is