Benders'dictionary of nutrition and food technology

367periodontal Relating to the tissues between the teeth; the periodontalmembrane is the ligament around a tooth, attaching itto the bone.peristalsis The wavelike rhythmic alternating contraction andrelaxation of smooth muscle that forces food through the intestinaltract in peristaltic waves.peritoneum Serous membrane of the abdominal cavity.periwinkle See winkle.perleche Dryness of the corners of the mouth; may be infected.Occurs in riboflavin deficiency.permeation In food packaging, the diffusion of molecules acrossthe package wall, with adsorption from the external atmosphereand desorption into the internal atmosphere.Permutit TM An ion-exchange resin.pernicious anaemia See anaemia, pernicious.peroxidase Enzyme (EC 1.11.1.17) that reduces hydrogen peroxide(H 2 O 2 ) to water, while oxidising another substrate. A relativelythermostable enzyme, frequently used as an index of theefficacy of blanching of fruits and vegetables.peroxide Any compound with the peroxy (—O—O—) group;atmospheric oxidation of unsaturated fatty acids producesperoxides. Also used to mean specifically hydrogen peroxide(H 2 O 2 ).peroxide number Or peroxide value; a measure of the oxidativerancidity of fats by determination of the lipid peroxides present.perry Fermented pear juice (in UK may include not more than25% apple juice) analogous to cider from apples. Sparklingperry is sometimes known as champagne perry.Persian apple See citron.Persian berry Yellow colour obtained from the berries of thebuckthorn, Rhamnus spp.; legally permitted in food in mostcountries. Contains the glucosides of rhamnetin and rhamnazin.persimmon Fruit of Diospyros virginiana (American persimmonor Virginia date) and D. kaki (Japanese persimmon, date plum,kaki or sharon fruit). Kaki may be eaten raw or cooked; Americanpersimmon develops a sour flavour if cooked.American, composition/100 g: (edible portion 82%) water64 g, 532 kJ (127 kcal), protein 0.8 g, fat 0.4 g, carbohydrate 33.5 g,ash 0.9 g, Ca 27 mg, Fe 2.5 mg, P 26 mg, K 310 mg, Na 1 mg, vitaminC 66 mg. A 25 g serving (1 fruit) is a good source of vitamin C.Japanese, composition/100 g: (edible portion 84%) water 80 g,293 kJ (70 kcal), protein 0.6 g, fat 0.2 g, carbohydrate 18.6 g(12.5g sugars), fibre 3.6g, ash 0.3g, Ca 8mg, Fe 0.2mg, Mg 9mg,P 17 mg, K 161 mg, Na 1 mg, Zn 0.1 mg, Cu 0.1 mg, Mn 0.4 mg,Se 0.6µg, vitamin A 81µg RE (2693µg carotenoids), E 0.7 mg, K