mycotoxins Compounds produced by filamentous fungi (and so
exclude mushroom toxins) that may accumulate to harmful
levels in foods without any adverse effect on the flavour or
appearance of the food; many are acutely or chronically toxic or
carcinogenic. The most important are: aflatoxins (produced by
Aspergillus spp.), ochratoxins (Aspergillus and Penicillium spp.),
monoliformin (Fusarium spp.), patulin (Aspergillus and Penicil-
lium spp.) and ergot alkaloids formed by Claviceps purpurea
growing on rye.
myenteron Muscle layers of the intestine, a layer of circular
muscles inside a layer of longitudinal muscles, responsible for
peristalsis.
myocardial infarction Damage to heart muscle due to ischaemia
(failure of the blood supply from the coronary arteries).
myofibril See muscle.
myoglobin haem-containing oxygen binding protein in muscle.
Responsible for the red colour of fresh meat, oxidised to brown
metmyoglobin as meat ages, or on cooking. When meat is cured
(see meat, curing) with nitrite, the myoglobin is converted to the
bright red nitrosomyoglobin.
myo-inositol See inositol.
myosin The major protein of muscle, about 40% of the total. A
globulin, insoluble in water but soluble in salt solution.
myristic acid A saturated fatty acid with 14 carbon atoms
(C14:0).
myrosinase The enzyme (thioglycosidase, EC 3.2.3.1) in mustard
seed and horseradish that hydrolyses myrosin or sinigrin to
glucose and allyl isothiocyanate, the pungent principle.
Mysore flour A blend of 75% tapioca and 25% peanut flour.
mysost See gjetost.
myxoedema Severe hypothyroidism (underactivity of the thyroid

gland, see thyroid hormones) in adults; the name is derived from
puffiness of hands and face due to thickening of skin. Signs
include coarsening of the skin, intolerance of cold, weight gain
and dull mental apathy, as well as reduced basal metabolic rate.
myxoxanthin carotenoid pigment in algae with vitamin a
activity.
N
naartje Afrikaans; a small tangerine; see citrus fruit.
NAASO North American Association for the Study of Obesity,
now called the Obesity Society; web site />NAD, NADP Nicotinamide adenine dinucleotide and nicoti-
namide adenine dinucleotide phosphate, the coenzymes derived
324
from niacin. Involved as hydrogen acceptors / donors in a wide
variety of oxidation and reduction reactions.
NAEL See no adverse effect level.
nalidixic acid Quinolone antibiotic used to treat intestinal (and
urinary tract) infections.
nam pla Thai; salted paste made from shrimps and small fish.
nan Indian flat bread, an egg dough prepared with white flour and
leavened with sodium bicarbonate, normally baked in a tandoor
(see tandoori).
nanofiltration A membrane process to separate particles with
molecular weights from 300–1000Da, using lower pressures than
reverse osmosis (see osmosis, reverse).
naphthoquinone The chemical ring structure of vitamin k;the
various chemical forms of vitamin K can be referred to as sub-
stituted naphthoquinones.
naringenin See naringin.
naringin A glycoside (trihydroxyflavonone rhamnoglucoside)
found in grapefruit, especially in the immature fruit. Extremely

bitter: dilutions of 1 part in 10000 parts of water can be detected.
Sometimes found in canned grapefruit segments as tiny, white
beads. Hydrolysed to the aglycone, naringenin, which is not
bitter.
naseberry Alternative name for sapodilla.
nashi See pear, nashi.
nasogastric tube Fine plastic tube inserted through the nose and
thence into the stomach for enteral nutrition.
nasturtium Both the leaves and seeds of Tropaeolum officinalis
can be eaten; they have a hot flavour. The seeds can be pickled
as a substitute for capers, and the flowers can be used to deco-
rate salads.
nata Filipino; thick gelatinous film grown on the surface of
coconut, sugarcane or fruit juice by fermentation with the acetic
acid bacterium Acetobacter aceti, which produces an extracellu-
lar cellulose polymer. Eaten as a dessert.
natamycin (or pimaricin) A polyene antifungal agent, from Strep-
tomyces natalensis, used as a coating on the surface of cheeses to
prevent the growth of mould or yeast.
national flour See flour, wheatmeal.
natriuretic Any compound that promotes excretion of sodium
salts in the urine; most diuretics are natriuretics.
natto Japanese; soya bean fermented using Bacillus natto.
Composition /100g: water 55g, 887kJ (212kcal), protein
17.7g, fat 11g (of which 16% saturated, 24% mono-unsaturated,
61% polyunsaturated), carbohydrate 14.4g (3.6g sugars), fibre
5.4g, ash 1.9g, Ca 217mg, Fe 8.6mg, Mg 115mg, P 174mg, K
325
729mg, Na 7mg, Zn 3mg, Cu 0.7mg,Mn 1.5mg,Se 8.8µg, vitamin
K 23.1mg, B

1
0.16mg, B
2
0.19mg, B
6
0.13mg, folate 8µg, pan-
tothenate 0.2mg, C 13mg.
Natual
TM
Low cholesterol cheese, prepared by use of
cyclodextrin.
natural foods A term widely used but with little meaning and
sometimes misleading since all foods come from natural sources.
No legal definition seems possible but guidelines suggest the
term should be applied only to single foods that have been sub-
jected only to mild processing, i.e. largely by physical methods
such as heating, concentrating, freezing, etc., but not chemically
or ‘severely’ processed.
natural water See water, mineral.
nature-identical Term applied to food additives, including vita-
mins, that are synthesised in the laboratory and are identical to
those that occur in nature.
N balance (equilibrium) See nitrogen balance.
NCHS standards Tables of height and weight for age used as ref-
erence values for the assessment of growth and nutritional status
of children, based on data collected by the US National Center
for Health Statistics. The most comprehensive such set of data,
and used in most countries of the world.
N conversion factor See nitrogen conversion factor.
NDGA See nordihydroguaiaretic acid.

NDpCal See net dietary protein–energy ratio.
neat’s foot Ox or calf’s foot used for making soups and jellies.
Now called cow heels. Neat’s foot oil is obtained from the
knuckle bones of cattle; used in leather working and for canning
sardines.
Necator Genus of hookworms that are parasitic in the small
intestine; the human parasite is N. americanus.
necrosis Death of cells or tissues in an unprogrammed manner,
in response to toxicity or ischaemia.
See also apoptosis.
nectarine Smooth-skinned peach (Prunus persica var. nectarina).
Composition /100g: (edible portion 91%) water 87.6g, 184 kJ
(44kcal), protein 1.1g, fat 0.3g, carbohydrate 10.6g (7.9g sugars),
fibre 1.7g, ash 0.5g, Ca 6mg, Fe 0.3mg, Mg 9mg, P 26mg, K
201mg, Zn 0.2mg, Cu 0.1mg, Mn 0.1mg, vitamin A 17µg RE
(378µg carotenoids), E 0.8mg, K 2.2mg, B
1
0.03mg, B
2
0.03mg,
niacin 1.1mg, B
6
0.03mg, folate 5µg, pantothenate 0.2mg,C 5mg.
A 150g serving (1 fruit) is a source of Cu, vitamin E, C.
Neeld–Pearson reaction See carr–price reaction.
neep Scottish name for root vegetables; now used for turnip (and
sometimes for swede in England).
326
NEFA Non-esterified fatty acids.
negus Drink made from port or sherry with spices, sugar and hot

water.
NEL See no effect level.
nematode Any one of a large group of unsegmented worms; most
are free-living, but some, including hookworms and pinworms,
are intestinal parasites.
neohesperidin dihydrochalcone (NEO-DHC) A non-nutritive
sweetener, 1000 times as sweet as sucrose; formed by hydro-
genation of the naturally occurring flavonoid neohesperidin.
neomycin Broad spectrum aminoglycoside antibiotic isolated
from Streptomyces fradii that is poorly absorbed from the gas-
trointestinal tract and is used to treat persistent intestinal bac-
terial infections.
neonate Literally new-born, used to describe infants in the first
four weeks of life.
neotame Synthetic intense sweetener, 8000 times as sweet as
sucrose, N-[N-(3,3-dimethylbutyl)-l-α-aspartyl]-l-phenylalanine
1-methyl ester. See also aspartame.
nephrocalcinosis Presence of calcium deposits in the kidneys;
may result from vitamin d toxicity.
neroli oil Prepared from blossoms of the bitter orange by steam
distillation. Yellowish oil with intense odour of orange blossom.
net dietary protein calories See net dietary protein–energy
ratio.
net dietary protein–energy ratio (NDpE) A way of expressing
the protein content of a diet or food taking into account both the
amount of protein (relative to total energy intake) and the
protein quality. It is protein energy multiplied by net protein
utilisation divided by total energy. If energy is expressed in kcal
and the result expressed as a percentage, this is net dietary
protein calories per cent, NDpCal%.

See also net protein value.
net protein ratio (NPR), net protein utilisation (NPU) Measures
of protein quality.
net protein value A way of expressing the amount and quality of
the protein in a food; the product of net protein utilisation and
protein content per cent.
See also net dietary protein–energy ratio; protein
quality.
neural tube defect Congenital malformations of the spinal cord
caused by failure of the closure of the neural tube in early embry-
onic development (before day 28 of gestation). Supplements of
folic acid (400µg/day) begun before conception reduce the risk
significantly.
327
neuritis Inflammatory disease of peripheral nerves.
See also neuropathy.
neuropathy Any disease of peripheral nerves, usually causing
weakness and numbness.
See also neuritis.
neuropeptide Y A peptide neurotransmitter involved in the
control of appetite and feeding behaviour, especially in response
to leptin.
neutron activation analysis The nuclei of a number of elements
will capture a neutron on exposure to a neutron beam, leading
to the formation of unstable (radioactive) isotopes which can
then be measured by the radiation emitted as they decay.
Used for determination of whole body calcium, chlorine and
nitrogen.
new cocoyam See tannia.
New Zealand process Drying process for meat. It is immersed in

hot oil under vacuum when it dries to 3% moisture in about 4h.
NFE See nitrogen-free extract.
NFLEA US National Food Labelling and Education Act, 1993,
the basis of nutrition labelling of foods and health claims that
may be made.
nham South-east Asian; semi-dry uncooked pork or beef sausage
left to undergo lactic acid bacterial fermentation for 4–5
days.
niacin (see p. 329) A vitamin; one of the B complex without a
numerical designation. Sometimes (incorrectly) referred to as
vitamin B
3
, and formerly vitamin PP (pellagra preventative).
Deficiency leads to pellagra, photosensitive dermatitis resem-
bling severe sunburn, a depressive psychosis and intestinal dis-
orders; fatal if untreated.
Niacin is the generic descriptor for two compounds in foods
that have the biological activity of the vitamin: nicotinic acid
(pyridine carboxylic acid) and nicotinamide (the amide of nico-
tinic acid). In the USA niacin is sometimes used specifically to
mean nicotinic acid, and niacinamide for nicotinamide.
The metabolic function of niacin is in the coenzymes NAD
(nicotinamide adenine dinucleotide) and NADP (nicotinamide
adenine dinucleotide phosphate), which act as intermediate
hydrogen carriers in a wide variety of oxidation and reduction
reactions. In cereals niacin is largely present as niacytin, which
is not biologically available (see availability); therefore the pre-
formed niacin content of cereals is generally ignored when cal-
culating intakes.
See also niacin equivalents.

328
niacinamide American name for nicotinamide, see niacin.
niacin equivalents Nicotinamide can be formed in the body from
the amino acid tryptophan; on average 60mg dietary tryptophan
is equivalent to 1mg preformed niacin.The total niacin content
of foods is generally expressed as mg niacin equivalents; the sum
of preformed niacin (excluding that in cereals, see niacytin) plus
one-sixtieth of the tryptophan.
niacinogens Name given to protein–niacin complexes found in
cereals; see also niacytin.
niacin toxicity High doses of nicotinic acid have been used to
treat hypercholesterolaemia; they can cause an acute flushing
reaction, with vasodilatation and severe itching (nicotinamide
does not have this effect, but is not useful for treatment of hyper-
cholesterolaemia). Intakes of niacin above 500mg/day (the ref-
erence intake is 17mg/day) can cause liver damage over a period
of months; the risk is greater with sustained release preparations
of niacin.
niacytin The main form of niacin in cereals. Nicotinic acid ester-
ified as nicotinoyl-glucose in oligosaccharides and non-starch
polysaccharides; susceptible to alkaline hydrolysis and partially
susceptible to acid hydrolysis in the stomach. However, because
of variable availability, it is conventional to exclude the niacin
content of cereals from calculations of intake.
See also niacinogens.
nib See chocolate.
nibbler Machine for comminution of dry foods using grating
action rather than grinding as in mills.
niceritol Penta-erythritol tetranicotinate, a derivative of niacin
used as a hypolipidaemic agent.

nickel A mineral (see mineral, ultratrace) known to be essen-
tial to experimental animals, although its function is not known.
There is no information on requirements. Metallic nickel is used
as a catalyst in the hydrogenation of fats.
nicotinamide (niacinamide) One of the vitamers of niacin.
329
NIACIN
nicotinamide adenine dinucleotide (phosphate) See nad.
nicotinate, sodium Sodium salt of nicotinic acid; has been used,
among other purposes, to preserve the red colour in fresh and
processed meats.
nicotinic acid (see p. 329) One of the vitamers of niacin.
NIDDK National Institute of Diabetes and Digestive and Kidney
Diseases; web site />nigella Peppery seeds of the wild onion, Nigella sativa.
Nigerian berry See serendipity berry.
nigerseed Or nug, Guizotia abyssinica; grown in India and
Ethiopia as food crop.
night blindness Nyctalopia. Inability to see in dim light as a result
of vitamin a deficiency.
See also dark adaptation; vision.
nim leaf Sweet nim, an aromatic Indian herb with an aroma
resembling that of truffles.
ninhydrin test For proteins and amino acids (actually for the
amino group). Pink, purple or blue colour is developed on
heating the amino acid or peptide with ninhydrin (triketohy-
drindene hydrate).
nip The gap between rollers in a mill or a moulding/forming
machine.
nisatidine See histamine receptor antagonists.
nisin antibiotic isolated from lactic Streptococcus group N;

inhibits some but not all Clostridia; not used clinically. The only
antibiotic permitted in the UK to preserve specified foods. It is
naturally present in cheese, being produced by a number of
strains of cheese starter organisms. Useful to prolong storage life
of cheese, milk, cream, soups, canned fruits and vegetables,
canned fish and milk puddings. It also lowers the resistance of
many thermophilic bacteria (see thermophiles) to heat and so
permits a reduction in the time and/or temperature of heating
when processing canned vegetables.
nitrates The inorganic form of nitrogen used by plants; found in
soils and included in inorganic fertiliser. Nitrate is a natural con-
stituent of crops in amounts sometimes depending on the content
in the soil. Also found in drinking water as a result of excessive
use of fertilisers. Health problems can arise because within a day
or two of harvesting some crop nitrates are converted into
nitrites which can react with the haemoglobin (especially fetal
haemoglobin) to form methaemoglobin which cannot transport
oxygen. An upper limit of 45–50mg nitrate/L drinking water has
been recommended for infants. Also used, together with nitrite,
for curing meat (see meat, curing).
See also nitrosamines.
330
nitric oxide (NO) Synthesised in most mammalian cells by the
action of nitric oxide synthetase (EC 1.14.13.39) on arginine.It
causes vasodilatation and inhibits platelet aggregation (and so
has anticoagulant action), acting by cell surface receptors and
intracellular guanylate cyclase (EC 4.6.1.2), leading to increased
formation of cyclic GMP. Before it was identified, NO was known
as the endothelium-derived relaxation factor.
nitrites Found in many plant foods, since they are rapidly formed

by the reduction of naturally occurring nitrate. Nitrite is the
essential agent in preserving meat by pickling, since it inhibits
the growth of Clostridia; it also combines with the myoglobin of
meat to form the characteristic red nitrosomyoglobin.
See also nitrosamines.
nitrogen A gas comprising about 80% of the atmosphere; in
nutrition the term ‘nitrogen’ is used to refer to ammonium salts
and nitrates utilised as plant fertilisers; proteins and amino acids
as animal nutrients; and urea and ammonium salts as excretory
products.
nitrogenase The enzyme (EC 1.18.6.1 or 1.19.6.1) in nitrogen-
fixing micro-organisms that catalyses the reduction of N
2
to
ammonia. Irreversibly inactivated by oxygen.
See also leghaemoglobin.
nitrogen balance (N balance) The difference between the dietary
intake of nitrogen (mainly protein) and its excretion (as urea and
other waste products). Healthy adults excrete the same amount
as is ingested, and so are in nitrogen equilibrium. During growth
and tissue repair (convalescence) the body is in positive N
balance, i.e. ingestion is greater than loss and there is an increase
in the total body pool of nitrogen (protein). In fevers, fasting and
wasting diseases (see cachexia) the loss is greater than the intake
and the individual is in negative balance; there is a net loss of
nitrogen from the body.
nitrogen conversion factor Factor by which total nitrogen content
of a material (measured chemically, e.g. by the kjeldahl deter-
mination) is multiplied to determine the protein; depends on the
amino acid composition of the proteins concerned. Wheat and

most cereals 5.8, rice 5.95, soya 5.7, most legumes and nuts 5.3,
milk 6.38, other foods 6.25. Errors arise if part of the nitrogen is
non-protein nitrogen. In mixtures of proteins, as in dishes and
diets, the factor of 6.25 is used. Crude protein is defined as N ×
6.25.
nitrogen equilibrium See nitrogen balance.
nitrogen-free extract (NFE) In the analysis of foods and animal
feedingstuffs, the fraction that contains the sugars and starches
plus small amounts of other materials.
331
nitrogen, metabolic Nitrogen in the faeces derived from internal
or endogenous sources, as distinct from nitrogen-containing
dietary sources (exogenous nitrogen). This nitrogen consists of
unabsorbed digestive juices, mucus, shed intestinal mucosal cells
and intestinal bacteria, and continues to be excreted on a
protein-free diet.
nitrogen trichloride See agene.
nitro-keg beer conditioned in kegs under nitrogen, to give a
smoother,creamier beverage than traditional conditioning under
carbon dioxide.
nitrosamines N-Nitroso derivatives of amines.Found in trace
amounts in mushrooms, fermented fish meal and smoked fish,
and in pickled foods,where they are formed by reaction between
nitrite and amines. They cause cancer in experimental animals,
but it is not known whether the small amounts in foods affect
human beings.They are also found in human gastric juice, possi-
bly as a result of reaction between dietary amines and nitrites or
nitrates.
nitrosomyoglobin The red colour of cured meat, formed by the
reaction of nitrite with myoglobin.Fades in light to yellow-

brown metmyoglobin.
nitrous oxide N
2
O, a gas used as a propellant in pressurised
containers, e.g. to eject cream or salad dressing from
containers.
nivalenol Trichothecene mycotoxin produced when cereals are
infected with Fusarium spp.
nixtamal The paste produced by steeping maize in calcium
hydroxide solution to make tortillas and tacos; the process is
nixtamalisation.
N-lite
TM
fat replacer made from starch.
NMR Nuclear magnetic resonance.
NO See nitric oxide.
no adverse effect level (NAEL) Highest dose or intake of a com-
pound at which no adverse effect can be detected.
See also ld
50
; minimum lethal dose.
noble rot White grapes affected by the fungus Botrytis cinerea.It
spoils the grapes if they are damaged by rain, but if they are ripe
and healthy, and the weather is sunny, it causes them to shrivel
and concentrates the sugar, so that top-quality sweet wines can
be made.
See also wine classification, germany.
No Effect Level (NEL) With respect to food additives, the
maximum dose of an additive that has no detectable adverse
effects.

See also acceptable daily intake.
332
noggin Traditional measure of liquor =
1
/
4
pint (140mL); also
known as a quartern.
N-oil
TM
fat replacer made from starch.
nominal freezing time The time between the surface of the food
reaching 0°C and the thermal centre reaching 10°C below the
temperature of the first ice formation.
non-essential amino acids Those amino acids that can be
synthesised in the body and therefore are not dietary
essentials.
non-esterified fatty acids (NEFA) See fatty acids, free.
non-hygroscopic foods Foods that have a constant water vapour
pressure at different moisture contents, and so do not take up
moisture from the atmosphere.
noni (Indian mulberry) Fruit of the south Pacific evergreen shrub
Morinda citrifolia, with an unpleasant odour; the juice is claimed
to have healing properties and to be beneficial in treatment of
diabetes, heart disease and cancer.
non-Newtonian fluid See shear rate.
non-nutritive sweeteners See sweeteners, intense.
non-saponified The water-insoluble material remaining in a fat or
oil after saponification; mainly sterols, higher alcohols, hydro-
carbons and pigments.

non-starch polysaccharides (NSP) (see p. 334) Those polysac-
charides (complex carbohydrates) found in foods other than
starches.They are the major part of dietary fibre (see fibre,
dietary) and can be measured more precisely than total dietary
fibre; include cellulose, pectins, glucans, gums, mucilages,
inulin and chitin (and exclude lignin).The NSP in wheat, maize
and rice are mainly insoluble and have a laxative effect, while
those in oats, barley, rye and beans are mainly soluble and
have a blood cholesterol-lowering effect. In vegetables the pro-
portions of soluble to insoluble are roughly equal but vary in
fruits.
noodles pasta made with flour from various grains (e.g. rice,
wheat, buckwheat, mung bean starch) and water; may have egg
added.
nopales Stems or pads of the prickly pear cactus (Opuntia
spp.).
Composition/100g: (edible portion 96%) water 94.1 g, 67kJ
(16kcal), protein 1.3g, fat 0.1g, carbohydrate 3.3g (1.1g sugars),
fibre 2.2g, ash 1.1g, Ca 164mg, Fe 0.6mg, Mg 52mg, P 16mg, K
257mg, Na 21 mg, Zn 0.3 mg, Cu 0.1 mg, Mn 0.5 mg, Se 0.7 µg,
vitamin A 23µg RE (298µg carotenoids), K 5.3 mg, B
1
0.01mg,
B
2
0.04mg, niacin 0.4mg, B
6
0.07mg, folate 3µg, pantothenate
0.2mg, C 9mg.
333

334
NON-STARCH POLYSACCHARIDES
nor- Chemical prefix to the name of a compound indicating:
(1) One methyl (CH
3
) group has been replaced by hydrogen
(e.g. noradrenaline can be considered to be a demethylated
derivative of adrenaline).
(2) A homologue of a compound containing one methylene
(CH
2
) group fewer than the parent compound.
(3) An isomer with an unbranched side-chain (e.g. norleucine,
norvaline).
noradrenaline Hormone secreted by the adrenal medulla
together with adrenaline; also a neurotransmitter. Physio-
logical effects similar to those of adrenaline. Also known as
norepinephrine.
norconidendrin See conidendrin.
nordihydroguaiaretic acid (NDGA) Extracted from the creosote
bush, Larrea divaricata (Covillea tridentata); used as an antioxi-
dant for fats.
norepinephrine See noradrenaline.
nori Edible seaweed, Porphyra umbilicalis.
norite Activated charcoal used to decolourise solutions.
norleucine 2-Aminohexanoic acid, a non-physiological amino
acid, an unbranched isomer of leucine, commonly used as an
internal standard in amino acid analysis.
northern blot See blotting.
notatin See glucose oxidase.

nougat Sweetmeat made from a mixture of gelatine or egg
albumin with sugar and starch syrup, and the whole thoroughly
aerated. Originated in Montelimar in southern France.
Novadelox
TM
Benzoyl peroxide used for treating flour,see ageing.
novain Obsolete name for carnitine.
novel foods Foods and food ingredients consisting of, or contain-
ing, chemical substances not hitherto used for human consump-
tion to a significant extent in the locality in question (including
micro-organisms, fungi or algae and substances isolated from
them, and organisms obtained using genetic modification tech-
niques).A food or ingredient to which has been applied a process
not currently used for food manufacture or which has not been
previously marketed and which gives rise to changes that affect
its nutritional value or safety.
See also substantial equivalence.
Novelose
TM
A preparation of resistant starch. See starch,
resistant.
NPR Net protein ratio, a measure of protein quality.
NPU Net protein utilisation, a measure of protein quality.
NPV Net protein value, a measure of protein quality.
335
NSP See non-starch polysaccharides.
nubbing Term used in the canning industry for ‘topping and
tailing’ of gooseberries.
nucellar layer Of wheat, the layer of cells that surrounds the
endosperm and protects it from the entry of moisture.

nucleation The formation of a nucleus of water molecules that is
required for ice crystal formation.
nucleic acids Polymers of purine and pyrimidine sugar phos-
phates; two main classes: ribonucleic acid (RNA) and deoxyri-
bonucleic acid (DNA). Collectively the purines and pyrimidines
are called bases. DNA is a double-stranded polymer (the so-
called ‘double helix’) containing the five-carbon sugar deoxyri-
bose. RNA is a single-stranded polymer containing the sugar
ribose.
Not nutritionally important, since dietary nucleic acids are
hydrolysed to their bases, ribose and phosphate in the intestinal
tract; purines and pyrimidines can readily be synthesised in the
body, and are not dietary essentials.
nucleoproteins The complex of proteins and nucleic acids found
in the cell nucleus.
nucleosides Compounds of purine or pyrimidine bases with a
sugar, most commonly ribose. For example, adenine plus ribose
forms adenosine. With the addition of phosphate a nucleotide
is formed.
nucleotides Compounds of purine or pyrimidine base with a
sugar phosphate; the monomer units of DNA and RNA. Natural
constituents of human milk, often used to supplement infant
formulae.
nug See nigerseed.
nuoc mam Vietnamese, Cambodian; fermented fish sauce. The
fish is digested by autolytic enzymes in the presence of salt added
to inhibit bacterial growth.
nutmeg Dried ripe seed of Myristica fragrans; mace is the seed
coat (arillus). Both mace and nutmeg are used as flavourings in
meat products and bakery goods.

nutraceuticals Term for compounds in foods that are not nutri-
ents but have (potential) beneficial effects.
See also functional foods.
Nutrasweet
TM
See aspartame.
nutricines Biologically active ingredients in animal feedstuff used
to promote nutrition-based health.
nutrient density A way of expressing the nutrient content of a
food or diet relative to the energy yield (i.e. per 1000kcal or per
MJ) rather than per unit weight.
336
nutrient enemata See rectal feeding.
See also enteral nutrition; parenteral nutrition.
nutrients Essential dietary factors such as vitamins, minerals,
amino acids and fatty acids. Metabolic fuels (sources of energy)
are not termed nutrients so that a commonly used phrase is
‘energy and nutrients’.
nutrification The addition of nutrients to foods at such a level as
to make a major contribution to the diet.
nutrigenetics The study of the effects of genotype on nutrient
requirements and effects of diet on health.
See also nutrigenomics.
nutrigenomics The study of how nutrients interact with the
genome, and identification of nutrient-sensitive genes.
See also nutrigenetics.
nutrition The process by which living organisms take in and use
food for the maintenance of life, growth, the functioning of
organs and tissues and the production of energy; the branch of
science that involves these processes.

See also enteral nutrition; parenteral nutrition; rectal
feeding.
nutritional claim Any representation that states, suggests or
implies that a food has particular nutrition-related health prop-
erties. The extent of such claims on food labelling (see nutri-
tional labelling) and advertising are controlled by law in most
countries.
nutritional disorder Any morbid process or functional abnor-
mality of the body due to the consumption of a diet not con-
forming to physiological requirements,or to failure in absorption
or utilisation of the food after ingestion.
nutritional genomics General term to include both nutrigenet-
ics and nutrigenomics.
nutritional labelling Any information appearing on labelling or
packaging of foods relating to energy and nutrients in the food.
Voluntary in the EU; if nutritional information is given, it must
be in a standard format.The information must be given /100g (or
/100mL), and may also, optionally, be given per serving of a
stated size. In the USA nutritional labelling is obligatory, and
information must be given in a standard format per serving (as
defined by the Food and Drug Administration), and may option-
ally be given /100g or /100mL.
nutritional recommendations Recommendations comprising nutri-
ent goals, food goals and dietary guidelines. In addition to ref-
erence intakes of nutrients, key recommendations in developed
countries are reduction of total fat intake to 30% of energy
337
intake, with a more severe restriction of saturated fats (see fat,
saturated) (to 10% of energy intake); increase of carbohydrate
intake to 55% of energy intake (with a reduction of sugars to

10% of energy intake); increased intake of non-starch polysac-
charides and reduced intake of salt.
nutritional status assessment In adults,general adequacy of nutri-
tion is assessed by measuring weight and height; the result is
commonly expressed as the body mass index, the ratio of weight
(kg)/height
2
(m). Body fat may also be estimated, by measuring
skinfold thickness, and muscle diameter is also measured. For
children, weight and height for age are compared with standard
data for adequately nourished children. The increase in the cir-
cumference of the head and the development of bones may also
be measured. Status with respect to individual vitamins and min-
erals is normally determined by laboratory tests, either measur-
ing the blood and urine concentrations of the nutrients and their
metabolites, or by testing for specific metabolic responses.
See also anthropometry; enzyme activation assays.
nutritionist One who applies the science of nutrition to the pro-
motion of health and control of disease; instructs auxiliary
medical personnel; participates in surveys. Not legally defined in
the UK, but there is a Register of Accredited Nutritionists main-
tained by the Nutrition Society.
See also dietitian.
nutrition policy (or planning) A set of concerted actions, based
on a governmental mandate, intended to ensure good health of
the population through informed access to safe, healthy and ade-
quate food.
nutrition surveillance Monitoring the state of health, nutrition,
eating behaviour and nutrition knowledge of a given population
for the purpose of planning and evaluating nutrition policy.

Especially in developing countries, monitoring may include
factors that may be potential causes of nutritional emergencies,
in order to give early warning of such emergencies.
nutritive ratio In animal feeding;a measure of the value of a feed-
stuff for growth (or milk production) compared with its fatten-
ing value. It is the sum of the digestible carbohydrate, protein
and 2.3 × fat, divided by digestible protein. Ratio 4–5 for growth,
7–8 for fattening.
nutritive value index In animal feeding; intake of digestible
energy expressed as energy digestibility multiplied by voluntary
intake of dry matter of a particular feed, divided by metabolic
weight (weight
0.75
), compared with standard feed.
nutro-biscuit Indian; biscuit baked from a mixture of 60% wheat
flour and 40% peanut flour; contains 16–17% protein.
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nutro-macaroni Indian; mixture of 80 parts wheat flour, 20 parts
defatted peanut meal (19% protein).
nuts Hard-shelled fruit of a wide variety of trees, e.g. almonds,
brazil, cashew, peanut, walnut. All have high fat content,
45–60%; high protein content, 15–20%; 15–20% carbohydrate.
The chestnut is an exception, with 3% fat and 3% protein, being
largely carbohydrate, 37%. A number of nuts are grown mainly
for their oils; see oilseed.
NVDP Non-volatile decomposition products.
nyctalopia See night blindness.
nystagmus Rapid involuntary movement of the eyes, as when fol-
lowing a moving object; may also occur as a result of a congen-
ital defect, and in the wernicke–korsakoff syndrome due to

vitamin b
1
deficiency.
O
Oatrim
TM
fat replacer made from non-starch polysaccharide.
oats Grain from Avena spp., especially A. sativa, A. steritis and A.
strigosa. Oatmeal, ground oats; oatflour, ground and bran
removed; groats, husked oats; Embden groats, crushed groats;
Scotch oats, groats cut into granules of various sizes; Sussex
ground oats, very finely ground oats; rolled oats, crushed by
rollers and partially precooked.
Composition /100g: water 8g, 1628kJ (389kcal), protein
16.9g, fat 6.9g (of which 20% saturated, 37% mono-unsaturated,
42% polyunsaturated), carbohydrate 66.3g, fibre 10.6g, ash 1.7g,
Ca 54mg, Fe 4.7mg, Mg 177mg, P 523mg, K 429mg, Na 2mg, Zn
4mg, Cu 0.6mg, Mn 4.9 mg, vitamin E 1.1mg, B
1
0.76mg, B
2
0.14mg, niacin 1mg,B
6
0.12mg, folate 56µg, pantothenate 1.3mg.
A 30g serving is a source of Cu, Mg, P, vitamin B
1
,a rich source
of Mn.
obesity Excessive accumulation of body fat. A body mass index
(BMI) above 30kg/m

2
is considered to be obesity (and above 40
gross obesity). The desirable range of BMI for optimum life
expectancy is 20–25; between 25 and 30 is considered to be
overweight rather than obesity. People more than 50% above
desirable weight are twice as likely to die prematurely as those
within the desirable weight range.
obesity, dietary Obesity in experimental animals induced by over-
feeding, as opposed to pharmacological treatment or as a result
of genetic defects.
ob-ob mouse A genetically obese mouse; the defective gene
was cloned in 1994, and the gene product was identified as
leptin.
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