N-Acetyllactosamine synthases Alternative term
for lactose synthases.
Acetylmethylcarbinol Flavour compound found
commonly in dairy products and wines. Synonym
of acetoin.
N-Acetylneuraminic acid One of the organic acids,
synonym sialic acid. A nitrogen-containing
sugar derivative with a carbonyl functional group
found ubiquitously in complex carbohydrates.
Acha Species of cereal crop, Digitaria exilis, indigenous
to West and North Africa and grown for its grain.
Achromobacter Obsolete genus of Gram negative,
rod-shaped bacteria of the family Achromobactereaceae,
in which several parasitic and pathogenic
species were formerly grouped. Occur in soil, and
fresh and salt water. Some representatives have now
been designated to the genera Acinetobacter and
Alcaligenes.
Acid casein Casein produced by acid precipitation
from milk at its isoelectric point, pH 4.7. Acidification
can be achieved by direct addition of an acid or
through the action of lactic acid bacteria.
Acid curd cheese A cheese produced by microbial
ripening of quarg, ripening proceeding from the outside
of the cheese. Cultures used include bacteria,
fungi and yeasts, the selection depending on the type
of cheese being made.
Acidification Process by which the pH of a substance
is decreased to below 7 making it acidic.
Acidity The degree to which a substance or solution is
acidic, being dependent upon the concentration of hydrogen
ions. Level of acidity is expressed using pH.
Acidocins Bacteriocins produced by Lactobacillus
acidophilus.
Acidophilin Fermented milk prepared by fermentation
of milk with a mixture of lactic acid bacteria,
including Lactobacillus acidophilus, and kefir
grains.
Acidophilus milk Fermented milk produced by
fermentation of milk with Lactobacillus acidophilus.
Consumption of acidophilus milk has beneficial effects
on the intestine.
Acidophilus pastes Cultured milk products
made using curd resulting from milk acidification
with Lactobacillus acidophilus.
Acid phosphatases EC 3.1.3.2. Enzymes with
wide specificity which catalyse hydrolysis of orthophosphoric
monoesters into an alcohol and orthphosphate.
Also catalyse transphosphorylation. Important
for flavour development, e.g. in cheese and also
used as a marker of thermal processing in meat.
Acid rain Rain which has low pH caused by formation
of acids due to interaction of industrial gas emissions
with water. Studies with simulated acid rain have
shown adverse effects on yield and quality of exposed
crops, especially fruits such as apples, pears and
peaches. Fruit marketability and composition were
affected.
Acids Chemical compounds which release hydrogen
ions when dissolved in water, or whose H can be replaced
by metal atoms or basic radicals, or which react
with bases to form salts and water. Include both organic
acids and inorganic acids. Inorganic acids
may be used in food processing or cleaning of equipment.
Organic acids of many types are constituents of
a wide range of foods, both as natural constituents and
as processing aids. Important types of organic acids in
foods include fatty acids, amino acids and carboxylic
acids.
α-Acids Humulones. The main bitter compounds
of hops resins, used to impart a bitter taste to beer.
Converted to the more soluble and more bitter iso-
Acetolactate decarboxylases EC 4.1.1.5. These
enzymes can be used to reduce the maturation time in
winemaking by converting acetolactate to acetoin,
and to analyse diacetyl and acetoin concentrations in
beer during brewing. Expression of these enzymes in
brewers yeasts has also been used to reduce the
levels of diacetyl, thus reducing the time required for
lagering.
Acetomonas Former name for the genus Gluconobacter.
Acetone Smallest of the ketones, synonym propanone.
Widely used as a solvent in food analyses,
particularly for lipids and related compounds. Produced
along with butanol and ethanol as a microbial
fermentation product from unconventional feedstocks
including food processing wastes.
Acetophenone Aromatic ketone that is among the
flavour compounds in foods such as herbs, honeys
and katsuobushi.
Acetylacetone Ketone, synonym pentanedione,
which occurs in the flavour compounds of foods
and beverages, including beer, coffee and fermented
dairy products.
Acetylation Introduction of acetyl groups into a compound
or substance. Usually achieved by reaction with
acetic anhydride, acetic acid or an acetate such as
vinyl acetate. Sometimes used to protect hydroxyl
groups during organic syntheses. Such modification is
also used to alter the physicochemical properties,
functional properties or nutritional quality of substances
such as starch, proteins and carbohydrates.
Acetylcholinesterases EC 3.1.1.7. Convert acetylcholine
to choline and acetates. Act on a variety of
acetic esters and also possess transacetylase activity. A
number of inhibitors of these enzymes are used as
pesticides. As such, the enzymes can be used to detect
the presence of residues of these inhibitors in
foods and beverages.
Acetylene Hydrocarbon which acts as a plant growth
regulator and can be used to control ripening of
fruits.
N-Acetylglucosamine Derivative of the amino sugar
glucosamine in which the amino group is acetylated.
Component of cell walls and chitin.
Acetylglucosaminidases Acetylglucosaminidases Comprise a-Nacetylglucosaminidases
(EC 3.2.1.50), which hydrolyse
terminal non-reducing N-acetyl-D-glucosamine
residues in N-acetyl-a-D-glucosaminides, and mannosyl-
glycoprotein endo-b-N-acetylglucosamidases (EC
3.2.1.96), which catalyse endo-hydrolysis of the N,N'-
diacetylchitobiosyl unit in high-mannose glycopeptides
and glycoproteins containing the [Man(GlcNAc)2]Asn
structure; one N-acetyl-D-glucosamine residue remains
attached to the protein, while the rest of the oligosaccharide
is released intact.
Acetaldehyde Aldehyde, synonym ethanal. One of
the common flavour compounds in many foods and
beverages. May cause taints in some foods. Toxic
at excessive concentrations.
Acetals Group of diethers which occur as natural flavour
compounds in foods such as fruits and
herbs, and alcoholic beverages. May be used in
flavourings.
Acetan Anionic, xanthan-like exopolysaccharides
formed by Acetobacter xylinum. Of potential
use in thickeners or gelling agents.
Acetates Salts or esters of acetic acid. Flavour
compounds in many foods and beverages. May be
used as preservatives.
Acetic acid Member of the short chain fatty acids
group, which occurs in a range of foods and beverages.
May be one of the flavour compounds, or
cause taints, depending on food or beverage type and
the concentration at which it is present. Acetic acid is
the main constituent of vinegar. It may be used for
preservation or flavouring of foods.
Acetic acid bacteria Any Gram negative, aerobic,
rod-shaped bacteria, e.g. Acetobacter species and
Gluconobacter species, capable of oxidizing ethanol
to acetic acid. Occur on the surface of fruits,
vegetables and flowers, and in soil. Used industrially
in the manufacture of vinegar. May cause spoilage
of beer and wines.
Acetic fermentation The process by which certain
microorganisms (e.g. Acetobacter and Acetomonas
spp., and Gluconobacter oxydans) metabolize
an alcoholic substrate to form acetic acid, the
main constituent of vinegar. Alcoholic substrates can
be obtained from a variety of sources, such as fruits,
vegetables and grain.
Acetobacter Genus of Gram negative, strictly anaerobic,
rod-shaped acetic acid bacteria of the family
Acetobacteraceae, that are capable of oxidizing ethanol
to acetic acid. Occur on fruits and flowers. May
be responsible for spoilage of beer and wines.
Acetobacter aceti, A. aceti subsp. xylinum, A. acetigenum
and A. schuezenbachii are used in commercial
production of vinegar.
Acetoin Flavour compound found commonly in dairy
products and wines. Synonyms include 3-
hydroxy-2-butanone and acetylmethylcarbinol.
Absorbents Materials or substances that are capable
of absorption. Uses of absorbents include incorporation
within food packaging (to absorb oxygen as a
preservation technique, to control humidity, and to
manage aroma and flavour problems in packaged
foods) and for purification of foods and beverages,
such as drinking water and liquid foods.
Absorption Process involving molecules of one substance
being taken directly into another substance. Absorption
may be either a physical or a chemical process,
physical absorption involving such factors as solubility
and vapour-pressure relationships and chemical
absorption involving chemical reactions between the
absorbed substance and the absorbing medium. Absorption
includes such processes as the passage of nutrients
and other substances from the gastrointestinal
tract into the blood and lymph, and also the uptake
of water, fats and other substances into foods.
Acaricides Pesticides used to control mites and
ticks (family Acaridae), many of which are responsible
for animal diseases and spoilage of stored crops.
Commonly used examples are amitraz, bromopropylate,
coumaphos and fluvalinate. Residues in
foods may represent a health hazard to consumers.
ACC Abbreviation for the plant growth regulator, 1-
aminocyclopropane-1-carboxylic acid.
Acceptability The degree to which the quality of a
food is regarded as satisfactory.
Acceptable daily intake A safety level for substances
used as food additives. The acceptable daily
intake (ADI) is usually calculated as 1/100th of the
maximum dose of the substance that causes no adverse
effects in humans.
Acceptance The willingness to regard the quality of a
food as satisfactory.
Acephate Systemic insecticide used to control a wide
range of chewing and sucking insects (e.g. aphids,
sawflies and leafhoppers) in fruits and vegetables.
Classified by WHO as slightly toxic (WHO III).
Acerola Alternative term for Barbados cherries.
Acesulfame K Non-nutritive artificial sweetener
(trade name Sunett), approximately 200 times as sweet
as sucrose. Potassium salt derived from acetoacetic
acid, with good heat stability and a synergistic effect in
sweetener blends. Used in a variety of food applications,
including yoghurt, table-top sweeteners,
soft drinks, candy and other confectionery.
AAS Abbreviation for atomic absorption spectroscopy.
Abalones Marine gastropod molluscs belonging to
the family Haliotidae, which contains around 70 species;
widely distributed, but found mainly in the Western
Pacific (Japan and Australia), and also off California
and Southern Africa. Only the adductor muscle is
edible, having a mild sweet flavour; this muscle is
normally tenderized to soften the naturally tough, rubbery
texture. Marketed in a variety of forms, including
powdered, brined and canned products.
Abate Alternative term for the pesticide temephos.
Abattoirs Types of slaughterhouses where animals
are slaughtered for meat and offal. Abattoirs usually
include lairage (a holding area for live animals), a
slaughtering line and cold stores. Facilities for processing
of by-products (blood, intestines, skins, fat,
bristle, unusable waste products), and treatment of
waste water and air are often included.
Abondance cheese French semi-hard mountain
cheese made from milk of cows of the breeds Abondance,
Montbeliard and Tarine. Characterized by a
strong aroma and a complex flavour. The crust and a
grey layer beneath are removed before consumption.
Abreh Alternative term for abrey.
Abrey Sudanese non-alcoholic fermented beverages
made from sorghum.
Abscisic acid Plant growth regulator, important in
ripening of fruits and cereals.
Absidia Genus of fungi of the class Zygomycetes.
Occur as saprotrophs on decaying vegetable matter,
grains, soil or dung, and meat, or as parasites or
pathogens of plants or animals. Some species may
be used in the production of chitosan (e.g. Absidia
coerulea, A. glauca and A. atrospora).
Absinthe Liqueur flavoured with aniseed and
wormwood. Widely believed to be neurotoxic as a
result of thujone derived from wormwood; sale is
prohibited in many countries for this reason.