Benders'dictionary of nutrition and food technology

345asymmetry of the molecule. If the plane of light is rotatedto the right, the substance is dextrorotatory and is designatedby the prefix (+); if laevorotatory, the prefix is (−). Amixture of the two forms is optically inactive and is termedracemic.Sucrose is dextrorotatory but is hydrolysed to glucose (dextrorotatory)and fructose, which is more strongly laevorotatory,so hydrolysis changes optical activity from (+) to (−); hence, themixture of glucose and fructose is termed invert sugar (seesugar, invert).The obsolete notation for (+) was d- and for (−) was l-; this isquite separate from d- and l-, which are used to designatestereoisomerism, see d-, l- and dl-.opuntia See nopales; prickly pear.oral rehydration Administration of an isotonic solution of saltand glucose (or sucrose) to replace fluid and electrolytes lost indiarrhoea.orange citrus fruit, from the subtropical tree Citrus sinensis.Composition /100 g: (edible portion 73%) water 87 g, 197 kJ(47 kcal), protein 0.9 g, fat 0.1 g, carbohydrate 11.8 g (9.4 g sugars),fibre 2.4g, ash 0.4g, Ca 40mg, Fe 0.1mg, Mg 10mg, P 14mg, K181mg, Zn 0.1mg, Se 0.5µg, vitamin A 11 µg RE (327µgcarotenoids), E 0.2 mg, B 1 0.09 mg, B 2 0.04 mg, niacin 0.3 mg,B 6 0.06 mg, folate 30 µg, pantothenate 0.3 mg, C 53 mg. A 160 gserving (1 medium) is a good source of folate, a rich source ofvitamin C.orange, bitter The fruit of the subtropical tree Citrus aurantium;known as Seville orange in Spain, bigaradier in France, melangolin Italy and khush-khash in Israel. Used mainly as root stock,because of its resistance to the gummosis disease of citrus. Thefruit is too acid to be edible; used in manufacture of marmalade;the peel oil is used in the liqueur curaçao; the peel and floweroils (neroli oil) and the oils from the green twigs (petit-grain oils)are used in perfumery.orange butter Chopped whole orange, cooked, sweetened andhomogenised.orange roughy A deep-water fish (Hoplostethus atlanticus) thatturns orange after being caught; mainly caught around NewZealand.orcanella See alkannet.oreganum Or Mexican sage; see marjoram.orexigenic Stimulating appetite.orexins Also called hypocretins, two small peptide hormones synthesisedin the hypothalamus that stimulate appetite incretinssecreted by the hypothalamus.