Từ điển công nghệ N

N N 2 Chemical symbol for nitrogen gas. Na Chemical symbol for sodium. NAA Abbreviation for the analytical technique neu- tron activation analysis and the auxin naphtha- leneacetic acid. NaCl Chemical formula for sodium chloride. NAD(P) Abbreviation for nicotinamide adenine dinucleotide (phosphate). Naegleria Genus of amoebae of the family Vahl- kampfiidae. Occur in damp soil, mud, water and sew- age. Pathogenic to humans and animals. Naegleria fowleri, a water contaminant, is the causative agent of meningoencephalitis in humans. NAFTA Abbreviation for North American Free Trade Agreement. Nalidixic acid Quinolone antibiotic that exhibits an- tibacterial activity against various Gram negative bacteria. Used in poultry production and aquacul- ture. Nan Flat bread originating from northwest India made from white flour, leavened with sodium bicarbon- ate and baked in a tandoor. Nanofiltration Form of filtration that uses semi- permeable membranes of pore size 0.001-0.1 ȝm to separate different fluids or ions, removing materials having molecular weights in the order of 300-1000 Da. Nanofiltration is most commonly used to separate solu- tions that have a mixture of desirable and undesirable components. An example of this is the concentra- tion of corn syrups. Nanofiltration is capable of re- moving ions that contribute significantly to osmotic pressure, and this allows separation at pressures that are lower than those needed for reverse osmo- sis. Nanotechnology A field of science which in its broadest sense covers development of materials and devices of nanometer-scale (1-100 nm). Nanotechnol- ogy applications of relevance to the food industry in- clude: carbon nanotubes used in construction of bio- sensors and as adsorbents in solid phase mi- croextraction; structured colloids and emulsions for encapsulation of food ingredients; and nano- composites used in food packaging. NaOH Chemical formula for sodium hydroxide. Naphthalene Aromatic hydrocarbon with a distinctive coal tar-like odour. Used as an insecticide and in the synthesis of dyes. Naphthaleneacetic acid A synthetic member of the auxins group of plant growth regulators, chemi- cal name 2-(1-naphthyl)acetic acid. Used as a rooting agent, in plant tissue culture and to regulate the yield and quality of various fruits and vegetables. Naphthol Phenol that is a major metabolite of the insecticide carbaryl. 2-(1-Naphthyl)acetic acid Chemical name for the plant growth regulator naphthaleneacetic acid. Naphthylmethylcarbamate Alternative term for the insecticide carbaryl. Napins Storage proteins of rapeseeds (Brassica napus). Naranjilla Orange fruits with green-yellow flesh pro- duced by Solanum quitoense or S. angulatum. The juicy pulp is used in beverages and sherbet. Also eaten out of hand, and used as an ingredient in des- serts, jellies and marmalades. Rich in vitamin A and vitamin C. Alternative term for lulo and quito oranges. Narazuke Vegetables pickled in sake lees. Origi- nally made from uri, a cross between cucumbers and melons, but now made using aubergines, small melons, radishes and cucumbers. Naringenin Non-bitter flavanone found mainly in citrus fruits, but also in other fruits, e.g. tomatoes. Naringin Bitter glycoside present in citrus fruits. Naringinases Commercial crude fungal enzyme preparations consisting of Į- L -rhamnosidases and ȕ-glucosidases. Used to degrade naringin, a bitter flavonoid found in citrus fruits, during extraction of fruit juices in order to reduce bitterness to accept- able levels. Narirutin One of the flavanones found mainly in citrus fruits. Also known as naringenin 7-O- rutinoside. Has antioxidative activity. Nata Thick, white, mucilaginous mat formed by fer- mentation of Gluconacetobacter xylinus grown on the surface of coconut water, coconut milk or 292 Natamycin Neomycin other sugary fruit juices. Used in production of des- serts, including nata de coco which is popular in the Philippines. Natamycin One of the polyene antibiotics with an- tifungal activity, this one used in preservatives for foods such as dry sausages and cheese. Exhibits no antibacterial activity, so does not disturb natural ripening processes in these foods. Also known as pi- maricin. Natto Traditional Japanese product made by fermen- tation of soybeans with Bacillus subtilis (B. natto). Natural colorants Colorants that exist in nature. Natural flavourings Flavour compounds, also essential oils, extracts and hydrolysates containing flavour compounds, that are derived from natural sources, such as plants, animal foods and edible yeasts. Usually they have little or no nutritive value but are used solely to impart flavour. Natural foods Foods produced using natural farming techniques (e.g. organic foods) and subjected to minimal processing. Free from artificial ingredi- ents. Natural sweeteners Sweet-tasting substances that occur in nature. Saccharides, such as sucrose (sugar), D -glucose (dextrose) and fructose (laevulose) are the major natural sweeteners used by the food indus- try. Other natural sweeteners include sweet-tasting pro- teins (e.g. thaumatin), terpenoids (e.g. glycyr- rhizin), steroidal saponins (e.g. polypodoside A), dihydroisocoumarins (e.g. phyllodulcin) and flavon- oids (e.g. neohesperidin). Navy beans Type of common beans (Phaseolus vulgaris). N compounds Compounds that contain the element nitrogen. NDGA Abbreviation for nordihydroguaiaretic acid. Near infrared Infrared radiation which has a wave- length between 0.7 and 2.5 ȝm. Near infrared (com- monly abbreviated to NIR) is subdivided into very near infrared (0.7-1 ȝm) and short wave infrared (1.0-2.5 ȝm). Nectarines Fruits produced by Prunus persica var. nectarina. Similar to peaches in composition and flavour, but with a smoother skin and richer colour. Sweet, juicy flesh varies in colour from white to yel- low, depending on variety. Varieties also differ in stone tenacity (clingstone or freestone). Rich in vita- min A, vitamin C and potassium. Eaten out of hand or in salads, and used as a garnish, in toppings and in various desserts. Neem Common name for Azadirachta indica, a tree native to tropical Asia. Neem plants contain various bioactive compounds and thus have been used tra- ditionally as medicinal plants. Neem seed oils, seed cake and, to a lesser extent, leaf extracts can act as in- secticides and are used for preventing infestation of stored grain and vegetables . The antimicrobial activity of neem extracts may be exploited for con- trolling post-harvest spoilage of fruits and vegeta- bles. Nematocides Pesticides used for control of nema- todes that parasitize animals or infest crops. Gener- ally fall into two major classes, fumigants and non- fumigants (contact), based on chemical and physical characteristics. Commonly used examples include methyl bromide and oxamyl. Nematodes Group of worms which are members of the phylum Nematoda. Occur in soil, and fresh and marine waters. Some are parasites of humans, ani- mals and plants. Neocallimastix Genus of anaerobic fungi of the Neocallimastigaceae family. Grow on a range of sim- ple and complex carbohydrates in the rumen of animals. Species (e.g. Neocallimastix patriciarum and N. frontalis) are used in the production of enzymes (e.g. xylan degrading enzymes and cellulases). Neohesperidin Flavonoid glycoside bitter com- pounds present in bitter oranges (Citrus auran- tium). Exhibit poor water solubility, and are impor- tant flavour compounds in orange juices. The sugar component is a disaccharide, ȕ-neohesperidose (2-O-alpha- L -rhamnopyranosyl-ȕ- D -glucopyranose). Used as the raw material for manufacture of the sweet- ener neohesperidin dihydrochalcone. Neohesperidin dihydrochalcone Artificial sweeteners derived by hydrogenation of neo- hesperidin. 1500-1800 times sweeter than sucrose and stable in crystalline form, in solutions and at high temperatures. Possess a very light aftertaste and have a short delay to reach maximum sweetness percep- tion. Have a synergistic sweetening effect when com- bined with sugar alcohols such as xylitol and isomalt, and with other sweeteners such as aspar- tame and acesulfame K. Applications include bev- erages, desserts and savoury foods. Also used as flavour enhancers in a wide range of foods. Neomycin Aminoglycoside antibiotic produced by Streptomyces fradiae. Used for treatment of coliba- cillosis in sheep, goats, swine, turkeys and cattle, with the exception of veal calves. Withdrawal periods vary with species and tolerance values are specified for kidneys, fats, livers, meat, milk and turkey skin with fat. Parenteral use in food-producing animals is not permitted in some countries. 293 Neopullulanases Neurological shellfish poisoning Neopullulanases EC 3.2.1.135. Glycosidases which hydrolyse pullulan to panose (6-Į- D - glucosylmaltose). Useful for the production of mal- tooligosaccharides for use in foods as prebiotics and as non-cariogenic sweeteners. Can also hydro- lyse amyloses to maltose and catalyse transgly- cosylation reactions. Neosartorya Genus of fungi of the family Trichoco- maceae. Neosartorya fischeri, a heat resistant species, may be responsible for the spoilage of canned and bottled fruits. Neotame Trade name for one of the artificial sweeteners, a derivative of a dipeptide composed of the amino acids aspartic acid and phenyla- lanine (N-(N-(3,3-dimethylbutyl)- L -Į-aspartyl)- L - phenylalanine 1-methyl ester). Approximately 7000- 10,000 times sweeter than sugar. A free flowing white crystalline powder which is water-soluble and heat-stable, and can be used in cooking, baking and frozen foods, as well as in tabletop applications. Can be used in combination with other non-nutritive or nu- tritive sweeteners. Although similar to aspartame, neotame is degraded differently in the human digestive system, avoiding problems caused by the presence of phenylalanine for people suffering from phenylke- tonuria. Also used as flavour enhancers. Marketed by The NutraSweet Company. Authorized for use in many countries worldwide. Neoxanthin One of the xanthophyll carotenoids found in many fruits and vegetables, but particu- larly in spinach and other green leafy vegetables. Precursor of the plant hormone abscisic acid. In- duces apoptosis in prostate cancer cells. Nephelometry Technique used to determine the size and concentration of cells or particles in a solution by measuring the intensity of scattered light. Light scat- tering depends on the number and properties of the particles in the solution. Neral Aldehyde; cis-citral. Volatile flavour compound found in plant essential oils. Nerol Monoterpene alcohol. Volatile flavour com- pound found in many plant essential oils and in- volved particularly in the flavour and aroma of grapes and wines. Neroli oils Yellowish essential oils derived from bitter orange blossoms by steam distillation. Have an intense aroma of orange blossom. Net protein ratio Weight gain of a group of animals (e.g. rats) fed a test diet plus the weight loss of a simi- lar group fed a protein free diet, and the total divided by the weight of the protein consumed by the animals on the test diet. Net protein utilization Commonly abbreviated to NPU. An index of the nutritional values of pro- teins . This quality ratio indicates the amount of die- tary protein retained in the body under specific clinical conditions. Changes in body nitrogen levels following consumption of a dietary protein are compared with those following consumption of a protein-free diet for the same duration, and then the dietary nitrogen re- tained in the body is expressed as a proportion of ni- trogen intake. Nettings Nettings made with rubber thread which are used to enclose joints of meat, such as beef and ham, to prevent their disintegration during cooking. Health concerns are associated with possible formation of nitrosamines from vulcanizing agents used in formulating the rubber. Nettles Plants of the genus Urtica, including stinging or common nettles (U. dioica) and small nettles (U. urens). Leaves are rich in vitamin C and can be used as a vegetable when young. Also used in herbal prepa- rations and soups, and to make beer, wines and teas. Neural networks Systems of computer programs and data structures which are modelled on the human nerv- ous system and brain. Incorporate large numbers of processors operating in parallel, each with an individ- ual sphere of knowledge which has been fed into it along with rules about relationships. Networks can use this information to recognize patterns in large amounts of data. Used in the food industry to model processes and predict the behaviour of foods under specific con- ditions. Also known as artificial neural networks. Neural tube defects Congenital malformations of the spinal cord caused by the folds of the ectodermal neural plate failing to close properly in early embry- onic development. Failures to close at the top result in anencephaly, which is always fatal; failures to close along the spine result in spina bifida, which can have either a reasonably hopeful or a very poor prognosis depending on location and other characteristics of the opening. Supplements of folic acid begun before con- ception reduce the risk of neural tube defects develop- ing in the fetus. Neurodegenerative diseases Diseases character- ized by the degeneration of nerve cells (neurons) in the central nervous system. Includes Alzheimer's dis- ease, dementia, Parkinson's disease and Creutzfeldt- Jakob disease. Neurological shellfish poisoning Food poison- ing associated with consumption of shellfish con- taining neurotoxins produced by the dinoflagellate algae Pytchodiscus brevis. Gastrointestinal and neuro- logical symptoms normally occur within 3 to 6 hours of ingestion of contaminated shellfish. 294 Neurospora Nisin Neurospora Genus of fungi of the family Sordari- aceae. Neurospora spp. are responsible for spoilage of bread. N. intermedia is used as a starter for ont- jom and in the fermentation of bongkrek. N. crassa is industrially important for production of en- zymes. Neurotoxicity Property of being toxic to nervous system tissues. Neurotoxins Toxins that act specifically or primarily on nervous system tissues (e.g. botulotoxins and saxitoxin). Neutralization Process of making something chemi- cally neutral, with a pH of approximately 7. Neutron activation analysis Analytical technique in which samples are irradiated with a reactor, accel- erator or isotopic neutron source. Radioactive nuclides are produced by the addition of neutrons to nuclei of specific atoms and these nuclei release energy in the form of gamma rays or electrons to convert back to a stable state. The radiation detected is a measure of the energy of the nuclides produced in the sample. Com- monly abbreviated to NAA. NH 3 Chemical formula for ammonia. Niacin A member of the vitamin B group. Generic descriptor for two compounds in foods which have the biological activity of the vitamin: nicotinic acid (pyridine 3-carboxylic acid) and nicotinamide (the amide of nicotinic acid). The metabolic function of niacin is in the coenzymes nicotinamide adenine dinu- cleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP), which operate, often in partnership with thiamin and riboflavin coenzymes, to produce energy within the cells. Niacin is found in animal tis- sue as nicotinamide and in plant tissues as nicotinic acid; both forms are of equal niacin activity. Rich sources of niacin include livers, kidneys, lean meat, poultry meat, fish, rabbit meat, cornflakes (en- riched), nuts and peanut butter. Niacin can with- stand reasonable periods of cooking, heating and storage. Canning, drying and freezing result in little destruction of the vitamin. In cereals, niacin is largely present as niacytin, which is not biologically available. Deficiency of niacin leads to pellagra (pho- tosensitive dermatitis), depressive psychosis and intes- tinal disorders. Previously known as vitamin PP. Niacinamide Synonym for nicotinamide. Nicarbazin Coccidiostat used prophylactically for prevention of intestinal and caecal coccidiosis in chickens. Not used in laying hens due to detrimental effects on production of eggs. Withdrawal periods are specified for treated chickens. Nickel Transition element with the chemical symbol Ni. Nicotinamide Synonym for niacinamide and nicotinic acid amide. The amide form of nicotinic acid which has niacin activity as a constituent of 2 coenzymes (nicotinamide adenine dinucleotide (NAD) and nicoti- namide adenine dinucleotide phosphate (NADP)); these coenzymes act as intermediate hydrogen carriers in a wide variety of oxidation and reduction reactions. Nicotinamide can be formed in the body from the amino acid tryptophan; on average 60 mg of dietary tryptophan is equivalent to 1 mg of preformed niacin. Nicotinamide adenine dinucleotide (phosphate) A coenzyme derived from niacin ; commonly abbrevi- ated to NAD(P). Nicotine One of the alkaloids. The principal active ingredient in tobacco, and responsible for the addic- tive properties of cigarette smoking. Also found in lower quantities in foods belonging to the Solanaceae (nightshade) family, including tomatoes, potatoes, aubergines and peppers. Nicotinic acid A member of the vitamin B group found in plant tissues. Contributes, along with nicoti- namide found in animal tissues, to niacin activity. Chemical name pyridine 3-carboxylic acid. Nicotinic acid amide Synonym for nicotinamide. Nigerose Disaccharide composed of two glucose residues linked via an Į-1,3-glycosidic bond. Isomer of maltose. Niger seeds Seeds from the plant Guizotia abys- sinica, which is grown in India and Ethiopia as an oil- seeds crop. Nile perch Large freshwater fish species (Lates niloticus) widely distributed in lakes and rivers around Central Africa; a highly valued food fish. Fresh and frozen fillets are exported from Kenya, Tanzania and Uganda to markets in Europe, Israel and the USA. Nile tilapia Freshwater fish species (Oreochromis niloticus, formerly Tilapia nilotica) of high commer- cial importance belonging to the cichlid family (Cich- lidae). Widely distributed in rivers and lakes of Africa and also produced by aquaculture. Marketed fresh and frozen. NIR Abbreviation for near infrared. NIR spectroscopy Spectroscopy performed at wavelengths in the near infrared (NIR) region. Nisin Polycyclic peptide bacteriocins synthesized by Lactococcus lactis. Classed as lantibiotics and contain the unusual amino acids lanthionine, me- thyllanthionine, didehydroalanine and didehydroami- nobutyric acid. Used as preservatives in a variety of heat processed and low pH foods, such as processed cheese, meat and meat products, fish, and canned fruits and vegetables. Exhibit broad spec- trum inhibition of Gram positive bacteria including 295 Nitrates Nitrous oxide important foodborne pathogens and clinically rele- vant antibiotic resistant bacteria. Nitrates Salts of nitric acid found in many animal and plant foods as a result of use of nitrate fertilizers, the nitrification process in the soil, or use of sodium nitrate or potassium nitrate food additives. Health risks are associated with conversion of nitrates into ni- trites in the gastrointestinal tract. Contamina- tion of drinking water with nitrates from chemicals used in agriculture is a particular concern. Nitric acid Strong acid that forms nitrates with met- als, carbonates, hydroxides or oxides. Powerful oxidizing agent. Used in digestion or extraction of samples during analysis. Commercially utilized in pro- duction of fertilizers, explosives and dyes. Nitric oxide Gas (chemical formula NO) produced by reduction of nitric acid, nitrates or nitrites, or oxidation of ammonia. Nitrification Conversion of ammonia or other N compounds into nitrites or nitrates. Nitrites Salts of nitrous acid formed by reduction of nitrates. Can be oxidizing agents or reducing agents. Authorized as food additives for preser- vation of meat and cheese. Health risks are associ- ated with formation of nitrosamines from nitrites in the presence of amines. Nitrofurans Antibiotics banned from use in animal food production in many countries due to concerns that long term exposure in humans, as a result of consum- ing contaminated products, constitutes an increased risk factor for developing cancer. Includes furazoli- done, nitrofurazone and nitrovin. Nitrofurazone Broad-spectrum synthetic nitrofuran antibiotic that is banned for use in food animals in many countries due to the potential for residues ex- hibiting carcinogenicity to occur in edible tissues and milk. Illegal use may be indicated by the presence of semicarbazide, a metabolite of the drug, in foods. Nitrogen Colourless and odourless gas that constitutes approximately three-quarters of the Earth's atmosphere by volume. The common form is dinitrogen (chemical symbol N 2 ). Constituent of proteins, amino acids, and many other groups of chemicals, e.g. amines, al- kaloids and purines. Nitrogen compounds Compounds that contain the element nitrogen. Nitrogen dioxide Brown gas with the chemical for- mula NO 2 . Nitrogen monoxide Alternative term for nitric ox- ide. Nitrogen solubility index One of the physico- chemical properties. Defined as the nitrogen con- tent of an aqueous extract of a sample obtained under standard conditions expressed as a percentage of the sample nitrogen content. Particularly applied to the characterization of proteins. Nitrosamines Nitroso compounds with strong carcinogenicity formed by reaction of amines with nitrogen oxides or nitrites. Nitrosation Reaction of secondary amines or alky- lureas present in ingested foods with nitrites, forming nitroso compounds, such as nitrosamines, which may be carcinogenic. Methylguanidine, a compound present in several foods, is converted to a potent mutagen after nitrosation in the stomach. Can be inhib- ited by some dietary components, such as toco- pherols and various phytochemicals. Nitroso compounds Organic compounds con- taining the nitroso group, many of which are mutagens. N-Nitrosodiethylamine Volatile nitrosamine with mutagenic activity. Found in a range of foods, some- times as a result of indirect contamination, e.g. mi- gration from rubber or packaging materials, or as a result of formation during processing. N-Nitrosodimethylamine Volatile nitrosamine with mutagenic activity; commonly abbreviated to NDMA. Found in a range of foods, sometimes as a result of in- direct contamination, e.g. migration from rubber or packaging materials or as a result of formation during processing. Nitrosomonas Genus of Gram negative bacteria of the family Nitrosomonadaceae, occurring in soils and water. Oxidizes ammonia to nitrites. The type species, Nitrosomonas europaea, is utilized for bio- logical nitrogen removal from waste water , includ- ing food factories effluents . Nitroso pigments Pigments formed during curing of meat by the reaction of nitric oxide (synthesized by conversion of nitrites used in curing agents) with metmyoglobin or myoglobin. Responsible for the pink colour of cured meat. N-Nitrosopyrrolidine Volatile nitrosamine with mutagenic activity. May be formed in a range of foods, including bacon, during processing. Nitrosylmyoglobin The haem pigment of nitrite- cured meat. Formed by reaction of metmyoglobin with nitric oxide. Contributes to the red colour of cured meat, such as ham. Nitrous acid A weak acid with the chemical formula HNO 2 . Used as a mutagen and in tests of the resistance of bacterial spores. Implicated in the formation of nitric oxide in the gastrointestinal tract. Nitrous oxide Colourless gas with the chemical for- mula N 2 O, also known as dinitrogen oxide. Used as a mild anaesthetic (laughing gas). 296 Nivalenol Nonthermal processes Nivalenol Trichothecene produced by Fusarium spp. (e.g. F. nivale) during growth on foods such as wheat, rye, barley, corn and millet. Nixtamalization Traditional process used to improve the nutritional quality of corn. Nixtamalization in- volves cooking and steeping corn in a lime solu- tion, washing the corn (nixtamal) and stone grinding nixtamal to form a corn dough or masa. Masa is used to produce nixtamalized products (e.g. corn tortillas, tortilla chips, corn chips and taco shells). N-Lite D Trade name (of National Starch) for a waxy corn maltodextrin which is one of a number of fat substitutes used in dairy products, particularly ice cream. It imparts creaminess to low fat frozen desserts, and improves their mouthfeel and melt- ing properties. NMR Abbreviation for nuclear magnetic reso- nance. NO 2 Chemical formula for nitrogen dioxide. Nocardia Genus of aerobic, rod-shaped or filamentous Gram positive bacteria of the family Nocardiaceae. Occur in soil. Some species are causative agents of mastitis in cattle; outbreaks are uncommon, how- ever, and have typically been reported on dairy farms with poor hygiene and management conditions. Other species may be used in the production of biosurfac- tants. A range of Nocardia species are used in bio- technological applications for production of a variety of enzymes and in bioconversions. Nocardiopsis Genus of alkalophilic bacteria of the family Nocardiopsaceae. Found in soil. Type species is Nocardiopsis dassonvillei. Producers of a number of enzymes, including proteinases, glycosidases, pectate lyases, milk clotting enzymes and amy- lases. N-Oil Trade name (of National Starch) for tapioca- derived dextrins that are used as fat substitutes in a wide range of low fat foods. Provide a creamy, fat- like texture to foods such as salad dressings, sauces, spreads and ice cream. Nomilin One of the limonoids with anticarcinogenic activity found in citrus fruits. Contributes to bitter- ness of citrus juices. Can be added to foods as a flavour compound or bittering agent. Nomograms Graphical plots in the form of line charts which may be used to solve particular types of equa- tions. Scales for the variables involved in the formula are presented in a way such that corresponding values for each variable are on a straight line intersecting all scales. Thus, when values for two variables are known, the value of a third can be read from its scale. Nonachlor Component of the organochlorine insecti- cide chlordane . May accumulate in animal tissues and milk, where it persists for long periods. Nonanal Aldehyde important for the flavour and aroma of many foods. Nonanone Methyl ketone that is important for the flavour and aroma of many foods including dairy products, fruits and vegetables. Nonenal Aldehyde important for the aroma of many foods. Also involved in formation of cardboard off flavour in beer. Nonenzymic browning Food browning process promoted by heat treatment, which includes a wide range of reactions, such as the Maillard reaction, caramelization, chemical oxidation of phenols and madeirization. Noni Fruits of Morinda citrifolia which have a pun- gent aroma when ripening. Used to produce fruit juices approved as novel foods by the European Commission. Also called Indian mulberries, cheese fruit or vomit fruit. Noni juices Traditionally prepared in the Hawaian and Tahitan islands by ageing noni fruits (Morinda citrifolia; Indian mulberries) in closed vessels for sev- eral weeks, prior to consumption as a cure-all folk medicine. Now commercially available globally in health beverages. In vitro studies suggest they can provide a range of health promoting effects, such as radical scavenging activity. Little clinical data ex- ist to support such claims, but noni juice contains high levels of fibre, vitamin C and various phytochemi- cals. Pure noni juice has a bitter flavour, and com- mercial products usually contain other ingredients, such as grape juices. Nono Nigerian fermented milk product. Nonreducing sugars Sugars that do not have a free carbonyl group (ketone or aldehyde) and therefore are not able to act as reducing agents. Nonstarch polysaccharides Components of die- tary fibre . Occur in 2 forms - insoluble and soluble. Both types are found in many plant foods. Thought to provide a range of health benefits. Nonthermal processes Processing techniques that do not require heat. Usually refers to food pas- teurization and sterilization treatments that do not employ heat during processing. Examples include: high pressure processing (inactivates vegetative microorganisms); ultrasonication (inactivates vege- tative bacteria and reduces heat resistance of bacte- rial spores); high voltage electric pulse treatment (electroporation; inactivates vegetative microorgan- isms); ionizing radiation treatment (inactivates pathogens); high intensity light pulse treatment (in- 297 Noodles Nostoc activates vegetative bacteria); and high intensity magnetic fields processing (inactivates microorgan- isms). Noodles Elongated, ribbon-like pasta made with eggs, and rice, wheat or buckwheat flour. Used in European and Oriental cuisine. Often used to add bulk to soups and stews. Nootkatone Sesquiterpene that is one of the essential aroma compounds in grapefruit. Noradrenaline One of the catecholamines. It pro- duces a wide range of physiological effects within the body, including vasoconstriction, increases in heart rate and blood pressure, and release of glucose from energy stores. These effects are part of the fight- or-flight response that enables the body to respond to stressful situations. In animals, the release of cate- cholamines as a result of preslaughter stress may be associated with poor meat quality. Also known as norepinephrine. Norbixin One of the dicarboxylic carotenoid pig- ments present in seeds of the shrub Bixa orellana. The main water soluble component of the natural or- ange colorant, annatto. Nordihydroguaiaretic acid Phenolic lipid soluble lipoxygenase inhibitor that is used mainly in antioxi- dants for fats and oils. Often abbreviated to NDGA. Norflurazon Selective pyridazinone herbicide used for pre-emergence control of annual and perennial grasses and broad-leaved weeds around crops, including fruits and nuts. Classified by WHO as unlikely to present acute hazard in normal use. Norharman ȕ-Carboline formed from tryptophan during heating. Demethylated analogue of harman, its co-mutagen. Nori Dried seaweed product obtained from red algae in the genus Porphyra (particularly P. tenera and P. yezoensis). Popular in Japan, where it is often con- sumed in toasted form. Good source of vitamin B 12 , dietary fibre and certain minerals; may possess an- ticarcinogenicity. Norisoprenoids C 13 butene cyclohexene degradation products formed by the cleavage of carotenoids. Im- portant aroma compounds in fruits, wines and honeys. Includes both Į- and ȕ-ionones and ȕ- damascenone. Noroviruses Enteric viruses of the family Caliciviridae, which cause viral gastroenteritis. Foodborne transmission is usually associated with con- sumption of contaminated water, molluscs or ready to eat foods. Person-to-person transmission is possi- ble. Also known as Norwalk-like viruses or small round structured viruses. North American Free Trade Agreement The North American Free Trade Agreement (NAFTA) is a trilateral regional pact that calls for the gradual re- moval of tariffs and other trade barriers on most goods produced and sold in North America. NAFTA, which became effective in Canada, Mexico and the USA on 1 January 1994, built upon a 1989 trade agreement be- tween the USA and Canada that eliminated or reduced many tariffs between the two countries. NAFTA called for immediate elimination of duties on half of all US goods shipped to Mexico and the gradual phasing out of other tariffs over a period of about 14 years. The treaty also protected intellectual property rights and outlined the removal of restrictions on investment among the three countries. Mandates for minimum wages, working conditions and environmental protec- tion were added later as a result of supplemental agreements signed in 1993. Northern blotting A method for analysing RNA. RNA is separated by electrophoresis, transferred to a chemically reactive matrix (e.g. nitrocellulose) on which it binds covalently in a pattern identical to that on the original gel, and detected by complementary la- belled probes (RNA or single-stranded DNA) that hy- bridize to specific RNA sequences. Norvegia cheese Norwegian semi-hard cheese simi- lar to Gouda cheese. Norwalk-like viruses Alternative term for norovi- ruses. Norwalk viruses Small round structured vi- ruses of the genus Norovirus and family Caliciviri- dae. Responsible for acute gastroenteritis in hu- mans. Transmitted by the faecal-oral route via con- taminated water and foods (e.g. shellfish and sal- ads). Norway lobsters Marine species of lobsters (Neph- rops novergicus ) found in the North Sea, the northeast Atlantic and the Mediterranean sea. Highly valued for their flesh. Marketed fresh (whole, tail meat with shell or shelled cooked or uncooked), frozen, semi- preserved or as a component of pastes and soups. Also known as Dublin Bay prawns, langoustines and scampi. Nostoc Genus of filamentous cyanobacteria of the family Nostocaceae. Occur naturally in damp habitats as green to black gelatinous colonies. Some species produce high levels of phycobiliproteins, making them a potential source of natural pigments for use in foods. Several species, e.g. Nostoc flagelliforme, are eaten in various countries, including China. N. com- mune is rich in dietary fibre and has been used in functional foods. 298 Nougat Nutrient requirements Nougat Aerated confectionery products made with honeys or sugar, egg whites and starch syrups. Often contains nuts, dried fruits and/or cherries and may be either chewy or brittle in consistency. Novagel Trade name (of FMC BioPolymer) for cellu- lose gels consisting of microcrystalline cellu- loses and guar gums. Used as fat substitutes in a variety of low fat foods, including salad dress- ings, processed cheese, dairy beverages and frozen desserts. Improves the mouthfeel, opacity and consistency of these foods. Novel foods Foods prepared using unconventional processes (particularly genetic technology), derived from unconventional sources or offering non- nutritional benefits. Examples include biotechno- logically derived foods, designer foods and medical foods. Novobiocin Narrow-spectrum antibiotic with anti- bacterial activity against many Gram positive bacteria. Frequently used in combination with peni- cillins for treatment of mastitis in cattle, and to con- trol cholera and staphylococcal infections in poultry. Withdrawal periods must be observed to ensure foods from treated animals are safe; tolerance values are specified for meat and milk. Use in poultry producing eggs for human consumption is not permitted. NPR Abbreviation for net protein ratio. NPU Abbreviation for net protein utilization. Nuclear magnetic resonance Spectroscopy technique based on the magnetic moment of atomic nuclei. An external magnetic field will partially align the axis of spin of spinning nuclei, but some precession about the magnetic field will occur. The precession de- pends on the magnetic field applied and the magnetic moment of the nucleus (dependent in turn on the chemical state of the atom), and is specific to the type of nucleus. The precession rate, measured by emission or absorption of applied radiofrequency, is used to give details about the composition of the sample. Com- monly abbreviated to NMR. Nuclear power Power generated by nuclear reactors in nuclear power plants or stations. Accidents at nu- clear power stations have caused fallout of radiocae- sium, and radioactive contamination of growing foods. Nucleases EC 3.1.11-EC 3.1.16 (exonucleases) and EC 3.1.21-EC 3.1.31 (endonucleases). Esterases that cleave the phosphodiester bonds between nucleo- tide subunits of nucleic acids. Nucleic acids Polymers of nucleotides in which the 3ƍ position of one nucleotide sugar is linked to the 5ƍ position of the next by a phosphodiester bond. The two major types are DNA and RNA. Nucleosides Compounds of purine or pyrimidine bases with a sugar, usually ribose. Nucleotidases EC 3.1.3.31. These phosphatases catalyse the dephosphorylation of nucleotides, form- ing nucleosides and orthophosphate. Exhibit a wide specificity for 2c, 3c and 5c-nucleotides, and also hydro- lyse glycerol phosphate and 4-nitrophenyl phosphate. Nucleotides Compounds of purine or pyrimidine bases with a sugar phosphate. Nucleotide sequences The order in which nucleo- tides are situated in nucleic acids, such as DNA and RNA molecules. Nukazuke Japanese fish product consisting of fer- mented fish (usually sardine) in rice bran-based pickles. Nuoc-mam Fermented fish sauces produced by fermenting anchovy (or other small marine fish) in salt, flavourings and spices for long periods. The resulting product is clear amber in colour . Used in Vietnamese and Thai cuisine. Nuruk Starters (comprising yeasts and other fungi) for Korean rice wines. Nutmeg One of the spices, along with mace, de- rived from seeds of Myristica fragrans. Kernels may be used whole, grated or ground. Characteristic fla- vour compounds include Į- and ȕ-pinene, myris- ticin, camphene, dipentene and sabanene. Nutmeg oils Essential oils obtained by steam dis- tillation of ground nutmeg (Myristica fragrans). Used as flavourings in bakery products, syrups, beverages and sweets, for example. Nut oils Oils extracted from nuts, such as almonds, hazelnuts and walnuts. Best used uncooked, as heat often destroys their delicate flavour. Nut pastes Pastes made from nuts that are used as the base for making confectionery fillings or nut spreads. Nut products General term referring to products de- rived or prepared solely from nuts. Nutraceutical foods Alternative term for func- tional foods. NutraSweet Registered brand or trade name of the low calorie sweetener aspartame. Nutria Large, semi-aquatic, herbivorous rodents of the family Myocastoridae, also known as coypu. Nu- tria (Myocaster coypus) are found in most continents, but originate from South America. Nutria provide meat that is low in fats and cholesterol, but mar- kets for this product have not been successfully estab- lished. Nutrient requirements Estimated levels of nutri- ents that are required to maintain health and prevent 299 Nutrients Nyufu diseases. Nutritional needs may vary according to age, gender, physical activity levels and state of health. Various sets of reference values have been es- tablished to provide guidance on nutrient recommenda- tions, including dietary reference intakes (DRI) and dietary reference values. Nutrients Essential dietary factors, such as vitamins, minerals, amino acids and fatty acids, that are required by the body but cannot be synthesized in the body in adequate amounts to meet requirements, so must be provided by the diet. Nutrient deficiency can cause poor growth, deformity, malfunctioning and ste- rility. A range of characteristic deficiency diseases is recognized in humans. Nutrigenetics The study of how a person's genetic makeup affects their response to diet or specific nu- trients. It aims to identify the effect of genetic vari- ants on responses to nutrients and to relate this to the risk for various diseases. Has the potential to provide a basis for personalized nutrition recommendations based on the individual's genotype in order to pre- vent diseases before their clinical manifestation. It has been applied in certain rare monogenic diseases, such as phenylketonuria (PKU). Nutrigenomics The study of how the diet or specific nutrients interact with genes to affect health and risk of developing various diseases. Understanding gene-nutrient interactions provides a basis for personalized nutrition recommendations based on an individual's genotype in order to prevent diseases be- fore their clinical manifestation. Nutrition Science of the relationship between foods, nutrients and health. A major aspect considered is the way by which an organism absorbs and utilizes food components. The study of nutrition involves identifica- tion of individual nutrients that are essential for growth and maintenance of the individual, interrelationships among nutrients within individual organisms, and quantitative requirements of organisms for specific nu- trients under various environmental conditions in order to optimize health. Nutritional assessment Assessment of the nutrient requirements or nutritional status of a person us- ing appropriate methods. Nutritional labelling Information appearing on la- belling or packaging of foods relating to energy and nutrients in the food. The information which must or may be given, and the format in which it must appear, is governed by law in most countries. Nutritional status State of the body in terms of the consumption, utilization and stores of nutrients. Nutritional values Indications of the potential contri- bution that a food or food component can make to- wards appropriate nutrition. Includes measures of the efficacy and quality of dietary constituents, such as bioavailability and protein values, and nutritional characteristics of foods and food components such as calorific values and glycaemic load. Nutritional values of foods may be affected by cultivation condi- tions, handling and storage practices, and proc- essing. Nuts Fruits consisting of an edible kernel within a shell, the thickness and hardness of which varies among types. Kernels have a high fat content and are often used as the source of nut oils. They are also rich in fibre, vitamin E, folic acid and a range of min- erals. Nuts are generally available shelled or un- shelled; shelled nuts are sold in many forms including raw, blanched, roasted and flavoured. They are eaten out of hand or used in a variety of sweet and savoury dishes. Commonly consumed nuts include walnuts, pistachio nuts, pine nuts, cashew nuts and al- monds. Some foods known as nuts are not true nuts, e.g. Brazil nuts are really seeds and peanuts are legumes. Nylon Family of strong, elastic polyamides materi- als, which vary from moderately flexible to strong, tough and rigid products. Can be shaped when heated into forms such as sheets, bristles and fibres. Resistant to greases and oils. Used widely in food packaging applications and for the immobilization of en- zymes and microorganisms. Nypa Genus of palms. The nipa palm (Nypa fruti- cans) is the source of a sugar -containing sap. Nystose Fructooligosaccharide comprising three fruc- tose residues and a glucose residue. Produced by hydrolysis of inulin or from sucrose via the action of fructosyltransferases. Nyufu Type of fermented tofu. O O 2 Chemical symbol for oxygen gas. O 2 absorbers Abbreviation for oxygen absorbers. Oak Hard, durable wood, usually with a distinct grain, obtained from oak trees, which belong to the many species within the genus Quercus. Used to impart a distinctive aroma and flavour to foods by various methods, including smoking (e.g. for meat prod- ucts and fish), storing and/or ageing in oak barrels (e.g. for wines and spirits), and addition of oak wood supplements or extracts. The term is also used to describe the smoky flavour and aroma characteristics of wines and spirits aged in oak barrels. Oat bran Outer layer found under the hull of the oat grain which forms the milling fraction. Oat fibre Indigestible material derived from oats, which comprises both soluble fibre and insoluble fibre. Used in snack foods, bakery products and meat extenders. Consumption is reported to reduce serum cholesterol levels. Oat flakes Whole kernels of oats that are processed by steaming, flattening through rollers and flaking (to retain most of their nutritional value) into quick cooking oats. Flakes are white to golden in colour and are used in breakfast cereals, bakery prod- ucts and for further processing into muesli. Oat flour Ground oat grains from which their outer layers have been removed. Used as an ingredient in bakery products and snack foods. Oat gums Gums produced from oats that are com- posed predominantly of (1o3)(1o4)-ȕ- D -glucan (ȕ- glucans). Used as thickeners in foods. Oatmeal Rolled or ground oats. Also refers to por- ridge made from rolled or ground oats. Oat oils Oils extracted from oats. Highly unsaturated and containing high levels of linoleic acid. Oatrim Trade name for fibre-rich fat substitutes made from hydrolysed oat flour and oat bran con- taining 5% ȕ-glucans soluble fibre. Imparts a creamy mouthfeel to a range of foods, including bakery products, salad dressings, confectionery and dairy products. Oats Edible starchy grain derived from plants belong- ing to the genus Avena, particularly A. sativa, A. steri- tis and A. strigosa, used as a cereal food. A rich source of vitamin B 1 ; also rich in protein and high in fat. Oat starch Starch isolated from oats. Obesity Condition in which body wt. is excessive due to the accumulation of body fat. Commonly de- fined as a body mass index of t30 kg/m 2 ; in con- trast to overweight (25-29.9 kg/m 2 ). Associated with increased risk of developing a range of diseases, such as cardiovascular diseases, adult-onset dia- betes and some forms of cancer. Lifestyle interven- tions to prevent or reverse obesity include adoption of a wt. loss diet, increased physical activity and/or consuming functional foods designed for this pur- pose. Obesumbacterium Genus of strictly aerobic, rod- shaped Gram negative bacteria of the family En- terobacteriaceae. Obesumbacterium proteus, a common contaminant of brewers yeasts, is respon- sible for producing off odour and nitrosamines in fermenting beer worts. Oca Common name for Oxalis tuberosa, the stem tu- bers of which are eaten like potatoes. The oxalic acid present in some cultivars can be removed by sun drying or freeze drying. Also known as iribia, cuiba and New Zealand yams. Ochratoxin A Most toxic of the known ochratox- ins. Produced by Aspergillus ochraceus and Penicil- lium verrucosum. Consumption of contaminated foods (e.g. cereals, oleaginous seeds, poultry meat, grapes, wines, pulses and green coffee) gives rise to human exposure. Potentially carcinogenic to humans, and also nephrotoxic and weakly mutagenic. Contaminated feeds have a major impact on the poultry industry, producing reduced wt. gain, poor feed conversion, reduced production of eggs and poor quality of egg shells. Ochratoxins Mycotoxins produced by certain spe- cies of Penicillium (e.g. P. viridicatum) and Asper- gillus (e.g. A. ochraceus) during growth on foods and feeds (e.g. wheat, rye, barley, oats, corn and pea- nuts). Nephrotoxic and carcinogenic in humans and animals (e.g. cattle and swine) when ingested in con- taminated foods and feeds. [...]... statistics and forecasts, on areas including agriculture, economic development and aid, education, employment, energy, the environment, health, science and technology, taxation and trade Also, it hosts various meetings, including annual meetings of finance and economic ministers from the member nations Organobromine compounds Organic halogen compounds containing one or more carbon-bromine bonds Include... bonding or indirectly via an oxygen atom Examples include thiols, methionine and allicin 306 Organization for Economic Cooperation and Development Organization for Economic Cooperation and Development An international organization founded in 1961 which provides a setting where governments compare policy experiences, seek answers to common problems, identify good practice and coordinate domestic and... contain one or more carbon atoms linked via covalent bonding to one or more halogen atoms (F, Cl, Br, I) This group includes organochlorine compounds, polybrominated biphenyls and chlorofluorocarbons Organic nitrogen compounds Organic compounds containing one or more carbon atoms linked via covalent bonding to nitrogen Amino acids, purines, pyrimidines and alkaloids are all examples of these compounds... comprising phosphorus-containing organic compounds Include organophosphorus Osmoregulation insecticides and acaricides, and some antifungal agents Organotin compounds Organic compounds which contain one or more atoms of tin Uses include as pesticides and fungicides Regarded as contaminants of foods, since some organotin compounds have been shown to be toxic when tested in animal models Examples include... polybrominated biphenyls such as polybrominated diphenyl ethers, which are flame retardants sometimes found as contaminants in environmental matrices, including fish Organochlorine compounds Organic compounds which contain one or more carbon-chlorine bonds Examples include organochlorine insecticides, organochlorine pesticides and solvents, such as chloroform and methylene chloride Organochlorine insecticides... main types - sweet, loose skinned and bitter The juicy pulp may or may not contain seeds according to cultivar All are rich in vitamin C, some B vitamins and minerals The sweet orange (Citrus sinensis) has the highest commercial production and is used for eating fresh and extraction of orange juices These include navel, Valencia and blood oranges Loose skinned oranges include mandarins and tangerines... insecticides Class of insecticides which are used widely for control of insects on crops and in food storage areas May persist for long periods in the environment and in animal tissues Some of the highly persistent products, such as aldrin, DDT and endrin, are subject to the Stockholm Convention on Persistent Organic Pollutants, and their use has been discontinued in many countries Organochlorine pesticides... concentrations of aroma compounds begins The concept of odour threshold is useful in defining aroma purity, estimating the necessary amount of starting material, serving as a reference point in describing intensity and aroma quality, and evaluating which components present are important in contributing to a characteristic aroma Offal OECD Abbreviation for Organization for Economic Cooperation and Development... labelling conditions, limitation to specific food applications (certain snack foods), and to fortification (with vitamins A, D, E and K) These conditions have subsequently been lifted, and olestra now has approval for use in specified food applications in the US Also known under the trade name Olean, marketed by Procter and Gamble Oleuropein One of the phenols present in olives and olive oils, responsible... water content Opaque 2 Variety of corn bred to contain higher levels of amino acids such as lysine and lower concentrations of zein Operators Sites within prokaryotic operons where repressor proteins bind to the DNA, thereby inhibiting transcription of adjacent genes Typically consist of or contain palindromic sequences, and may lie between promoters and the first structural genes of operons, or may . between cucumbers and melons, but now made using aubergines, small melons, radishes and cucumbers. Naringenin Non-bitter flavanone found mainly in citrus. oats, corn and pea- nuts). Nephrotoxic and carcinogenic in humans and animals (e.g. cattle and swine) when ingested in con- taminated foods and feeds.