Benders'dictionary of nutrition and food technology

343olive oil Pressed from ripe olives, the fruit of Olea europaea.Virgin olive oil is not refined and the flavour varies with thelocality where it is grown; extra virgin oil contains less than 1%acidity. Other types have been refined to varying extents. Usedin cooking, as salad oil, for canning sardines and for margarinemanufacture. 14% saturated, 76% mono-unsaturated, 10%polyunsaturated, contains 14 mg vitamin E, 60 mg vitaminK/100 g; also relatively rich in squalene.omasum See ruminants.omega fatty acids Polyunsaturated fatty acids (PUFA) aredescribed by chain length, number of double bonds and (in biochemistryand nutrition) by the position of their first doublebond counting from the terminal methyl group, labelled asomega (ω or n-). In systematic chemical nomenclature the positionof a double bond is numbered from the carboxyl end(carbon-1), but what is important nutritionally is that humanenzymes can desaturate fatty acids between an existing doublebond and the carboxyl group, but not between an existing doublebond and the methyl group.There are three series of PUFA: ω3, ω6 and ω9, derived fromlinolenic, linoleic and oleic acids, respectively. The first twocannot be synthesised in the body and are the precursors of twofamilies of eicosanoids.See also fatty acids, essential;Table 8.omega-3 (ω3) marine triglycerides A mixture of triacylglycerols(triglycerides) rich in two long-chain polyunsaturated fattyacids, eicosapentaenoic acid (EPA, C20:5 ω3) and docosohexaenoic(DHA, C22:6 ω3).omentum Double layer of peritoneum attached to the stomachand linking it to other abdominal organs. See gastrointestinaltract.OMNI Organising Medical Networked Information; web sitehttp://omni.ac.uk/.omophagia Eating of raw or uncooked food.oncogene Any gene associated with the development of cancer.Viral oncogenes are related to, and possibly derived from,normal mammalian genes (proto-oncogenes) that are involvedin the regulation of cell proliferation and growth. Mutation toyield an active oncogene involves loss of the normal regulationof the expression of the proto-oncogene.oncom Indonesian; fermented groundnut and soybean presscake with cassava, fermented with moulds: Neurospora sitophilato produce a red product or Rhizopus oligosporus for a greyproduct.onglet French; cut of beef corresponding to top of the skirt.