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.