Từ điển công nghệ thực phẩm - A

36 516 1
Từ điển công nghệ thực phẩm - A

Đang tải... (xem toàn văn)

Tài liệu hạn chế xem trước, để xem đầy đủ mời bạn chọn Tải xuống

Thông tin tài liệu

A AAS Abbreviation for atomic absorption spec- troscopy. Abalones Marine gastropod molluscs belonging to the family Haliotidae, which contains around 70 spe- cies; widely distributed, but found mainly in the West- ern Pacific (Japan and Australia), and also off Califor- nia and Southern Africa. Only the adductor muscle is edible, having a mild sweet flavour; this muscle is normally tenderized to soften the naturally tough, rub- bery 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 process- ing 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 Abon- dance, 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 bever- ages 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). Other applica- tions include the production of enzymes for use in the food industry (e.g. Į-galactosidases). Absinthe Spirits flavoured with aniseed and wormwood. Widely believed to exhibit neurotoxic- ity as a result of thujone derived from wormwood. The spirit was prohibited in many countries early in the 20th century. However, legal manufacture and sale of the beverage have become more widespread since the 1990s. Absorbents Materials or substances that are capable of absorption. Uses of absorbents include incorpora- tion 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 sub- stance being taken directly into another substance. Ab- sorption may be either a physical or a chemical proc- ess, physical absorption involving such factors as solu- bility and vapour-pressure relationships, and chemical absorption involving chemical reactions between the absorbed substance and the absorbing medium. Ab- sorption includes such processes as the passage of nu- trients and other substances from the gastrointesti- nal tract into the blood and lymph, and also the up- take of water, fats and other substances into foods. Acacia Plants of the genus Acacia (family Fabaceae), mostly tropical shrubs and trees. Acacia seeds are used as foods, and shoots may be used in soups, curries, omelettes and stir fries. Acacia honey has a mild flow- ery flavour. Several species of Acacia yield gums, such as gum acacia which is also known as gum arabic. Acai Small, dark purple fruits from the palms Eu- terpe oleraceae. The pulps and juices may be used in beverages, as well as in functional foods. Rich in dietary fibre and fatty acids, and have strong anti- oxidative activity. Acanthamoeba Genus of free-living amoebae which occur in soil and fresh water. Some species may be opportunistic pathogens. Acaricides Pesticides used to control mites and ticks (family Acaridae), many of which are responsible for animal diseases and spoilage of stored crops. Examples include amitraz, bromopropylate, couma- phos and fluvalinate. Residues in foods may repre- sent 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 sub- stances used as food additives. Usually calculated as 2 Acceptance Acetophenone 1/100th of the maximum dose of the substance that causes no adverse effects in appropriate test organisms. Abbreviated to ADI. Acceptance The willingness to regard the quality of a food as satisfactory. ACE inhibitors Enzyme inhibitors which inhibit activity of peptidyl-dipeptidase A, EC 3.4.15.1, also known as angiotensin converting enzyme or ACE. Inhibition of this enzyme in vivo leads to reduced vasoconstriction, thus ACE inhibitors exhibit anti- hypertensive activity and are components of some functional foods. Acephate One of a number of systemic organo- phosphorus insecticides 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 hazardous (WHO III). Acerola Alternative term for Barbados cherries. Acesulfame K One of the non-nutritive artificial sweeteners (trade name Sunett). A white crystal- line powder, approx. 200 times sweeter than sucrose. Often blended with other sweeteners to give a more sugar-like taste and to mask aftertaste. Stable under heat, and moderately acid or basic conditions. Used in foods and beverages since 1983 and approved by >100 countries worldwide. Used in beverages, dairy prod- ucts, preserves, bakery products, confection- ery, salad dressings and breakfast cereals. 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 fla- vour compounds in foods such as fruits and herbs, and alcoholic beverages. May be used in flavourings. Acetan Anionic, xanthan-like exopolysaccha- rides 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 bever- ages. 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 aerobic, rod-shaped Gram negative bacteria, e.g. Acetobacter spp. and Glu- conobacter spp., capable of oxidizing ethanol to acetic acid. Occur on the surface of fruits, vegeta- bles 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 acetic acid bacteria such as Acetobacter and Glucono- bacter spp. metabolize an alcoholic substrate to form acetic acid, the main constituent of vinegar. Alco- holic substrates can be obtained from a variety of sources, such as fruits, vegetables and grain. Acetobacter Genus of Gram negative, strictly aero- bic, rod-shaped acetic acid bacteria of the family Acetobacteraceae, that are capable of oxidizing etha- nol to acetic acid. Occur on fruits and flowers. May be responsible for spoilage of beer and wines. Acetobacter aceti and A. pasteurianus 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. Į-Acetolactate Molecular formula, C 5 H 8 O 4 ; syno- nym, 2-acetoxypropanoic acid. Precursor of the fla- vour compounds diacetyl and acetoin which are valuable in dairy products but which cause off fla- vour in sake and beer. Acetolactate decarboxylases EC 4.1.1.5. Decar- boxylases used to reduce maturation times in winemaking by converting acetolactate to acetoin, and in brewing to reduce levels of diacetyl, a cause of taints in beer. Also used to analyse diacetyl and acetoin concentrations in beer. Diacetyl produces a de- sirable aroma in dairy products, and development of lactic acid bacteria with reduced levels of these enzymes has been attempted. Acetolactate synthases EC 2.2.1.6. Transferases which catalyse the conversion of pyruvic acid to Į- acetolactate in the presence of its cofactor, thiamine diphosphate. These enzymes can also catalyse forma- tion of 2-ethyl-2-hydroxy-3-oxobutanoate from pyru- vate and 2-oxobutanoate. Involved in synthesis of amino acids (valine, isoleucine and leucine) and flavour compounds, including acetoin and diace- tyl. Acetomonas Former name for the genus Glucono- bacter. Acetone Smallest of the ketones, synonym pro- panone. Widely used as a solvent in food analyses, particularly for lipids and related compounds. Pro- duced along with butanol and ethanol as a microbial fermentation product from unconventional feed- stocks including food processing wastes. Acetophenone Aromatic ketone and one of the fla- vour compounds in honeys and a variety of other foods and beverages. A precursor for phenylethanol. 3 Acetylacetone Acidophilin Acetylacetone Ketone which occurs in the flavour compounds of foods and beverages, including beer, coffee and fermented dairy products. Also widely used as an analytical reagent, e.g. in the deter- mination of formaldehyde. Synonym is penta- nedione. Acetylation Introduction of acetyl groups into a com- pound 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 sub- stances such as starch, proteins and carbohy- drates. Acetylcholinesterases EC 3.1.1.7. Esterases which convert the neurotransmitter acetylcholine to choline and acetates. Act on a variety of other ace- tic esters and also possess transacetylase activity. In- hibition of these enzymes can be a marker for neu- rotoxicity. Some acetylcholinesterase inhibitors are used medically, e.g. to treat Alzheimer's disease, and some are used as pesticides. These enzymes can be used analytically to detect pesticide residues in foods and beverages. Acetylcholinesterase inhibitory activity has been found in essential oils and plant foods. Also known as cholinesterases. N-Acetyl- L -cysteine One of the antioxidant com- pounds used as food additives, e.g. to minimise browning and off flavour formation in fruit juices, other fruit products and vegetable products, and to inhibit haemagglutinins in legume meal. Also used to inhibit formation of biofilms on food contact surfaces. Commercially available as a food supplement claiming to provide detoxification effects and benefits to the immune system. 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 Comprise Į-N- acetylglucosaminidases (EC 3.2.1.50), which hydro- lyse terminal non-reducing N-acetyl- D -glucosamine residues in N-acetyl-Į- D -glucosaminides, and manno- syl-glycoprotein endo-ȕ-N-acetylglucosamidases (EC 3.2.1.96), which catalyse endo-hydrolysis of the N,Nc- 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 oligosac- charide is released intact. These glycosidases are involved in chitin degradation applications, and con- tribute to antibacterial activity in egg shell membranes and to autolysis due to autolysins in some bacteria. ȕ-N-acetylhexosaminidases EC 3.2.1.52. Glyco- sidases which catalyse the hydrolysis of terminal non-reducing N-acetyl- D -hexosamine residues in N- acetyl-ȕ- D -hexosaminides. Substrates include N- acetylglucosides and N-acetylgalactosides. Involved in degradation of polysaccharides including chitin. 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 ac- ids, synonym sialic acid. A nitrogen-containing sugar derivative with a carbonyl functional group found ubiquitously in complex carbohydrates. Acetyltransferases Acyltransferases which are members of the class EC 2.3.1 and catalyse transfer of acetyl groups, usually from acetyl-coenzyme A. Acha Species of cereal crop, Digitaria exilis, indige- nous to West and North Africa and grown for its grain. Achromobacter Genus of strictly aerobic, rod- shaped, non spore forming Gram negative bacteria of the family Alcaligenaceae. Occur in soil and water. Some species produce pigments and enzymes of industrial importance. 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 out- side 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 hy- drogen ions. Level of acidity is expressed using pH. Acidocins Bacteriocins produced by Lactobacil- lus acidophilus. Acidolysis Esterification reactions of acids with esters. Used to produce structured lipids (e.g. aci- dolysis of tristearin with long chain fatty acids) or to modify the lipid composition of fats and oils (e.g. acidolysis of seal blubber oils with lauric acid and interesterification of butterfat with CLA). Cata- lysed by lipases or chemical catalysts. Acidophilin Fermented milk prepared by fermenta- tion of milk with a mixture of lactic acid bacteria, 4 Acidophilus milk Acremonium 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. Hydrolases with wide specificity which catalyse hydrolysis of ortho- phosphoric monoesters into an alcohol and orthphos- phate. Also catalyse transphosphorylation. Widely dis- tributed in nature, and therefore found in a range of foods. Involved in acidity regulation in fruits, and in flavour development, e.g. in cheese. Also used as a marker of thermal processing in meat. Produced by microbial fermentation for commercial applica- tions. 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 re- placed by metal atoms or basic radicals, or which react with bases to form salts and water. Include both or- ganic acids and inorganic acids. Inorganic acids may be used in food processing or cleaning of equip- ment. 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 car- boxylic acids. Į-Acids The main bitter compounds of hops res- ins, used to impart a bitter taste to beer. Converted to the more soluble and more bitter iso-Į-acids during boiling of worts. Also known as humulones. ȕ-Acids Low-solubility resin constituents in hops which have little bittering capacity in beer. Also known as lupulones. Acids resistance Ability of organisms to withstand acidic conditions. Important for survival of microor- ganisms in acid environments such as the gastroin- testinal tract and during fermentation of foods. Acidulants Organic acids used in foods to control pH and fulfil a variety of functions. Applications in- clude preservation of meat products, flavour en- hancement, prevention of discoloration in sliced fruits, and prevention of development of rancidity in oils and fats. Commonly used acidulants in the food industry include citric acid, acetic acid, propionic acid and lactic acid. Acid values The level of free fatty acids present in lipids. The acid value, also known as the acid number, is determined by measuring the amount of KOH in milligrammes that neutralizes 1 g of the lipid. Acid values of fresh edible fats tend to be low and increase with storage as the glycerides present in the lipids break down to generate free fatty acids. Acid whey Whey produced by acid coagulation of milk during cheesemaking. Acinetobacter Genus of aerobic, rod-shaped, psy- chrotrophic Gram negative bacteria of the family Moraxellaceae. Occur in soil, water and raw milk, and on the surfaces of chilled meat and fish. Some spe- cies may be used in production of lipases (e.g. Acine- tobacter radioresistens and A. calcoaceticus). Ackee Common name for Blighia sapida, also known as akee. This fruit was introduced to the West Indies from West Africa and is particularly popular in Ja- maica. Fruits are pear shaped and can be consumed raw, cooked, or in canned or frozen forms. Unripe ackee contains hypoglycine A, a toxic amino acid, which can cause the potentially fatal Jamaican vomit- ing sickness. Levels of hypoglycine A rapidly diminish at maturity, but damaged or fallen fruit should not be consumed. Aconitic acid One of the organic acids found in sugar cane. Used in flavourings and acidulants for the food industry and also in the manufacture of emulsifying agents, plastics and detergents. Acorns Nuts obtained from the oak tree (Quercus spp.). Widely available, and used as a source of food by some populations, particularly in times of need. Can be pounded into meal for use in baked goods or used as coffee substitutes. Acorns are high in starch and are used in Korea to produce an edible starch gel known as mook. They also represent a source of edi- ble oils. Acoustics Study of the physical properties of sound; also refers to techniques based on transmission, gen- eration or reception of sound. Acoustic devices have been used to detect insects infestation of grain. Acoustics has also been employed in examining the structure of materials, e.g. pasta, and as the basis of non-destructive methods to determine the texture of foods, such as fruits, cheese and bakery prod- ucts. Acquired immunodeficiency syndrome Epi- demic disease commonly abbreviated to AIDS. Acremonium Genus of fungi of the phylum Asco- mycota. May be used in biotechnology for the pro- 5 Acrocomia Activation energy duction of cellulases (e.g. Acremonium cellulolyticus and A. alcalophilum). Acrocomia Genus of palms, including Acrocomia mexicana, which has edible fruits, and is used as a source of palm oils (oil of coyal) and in manufacture of palm wines. Also includes A. sclerocarpa, which has edible fruits that are used as a source of coconut- like oils. Acrolein Aldehyde, synonym propenal. Formed by microbial fermentation from the precursor 3- hydroxypropionaldehyde. Causes bitter, acrid off odour or off flavour problems in spirits and cider. Also occurs in overheated fats. Precursor for acrylamide. Acrylamide Synonym 2-propenamide (C 3 H 5 NO). Member of the amides which is a neurotoxin and ex- hibits carcinogenicity in animal models. Formed in foods during thermal processing as a product of the Maillard reaction between asparagine and re- active carbonyl compounds, e.g. in reducing sugars. Forms gels of polyacrylamides on polym- erization under specified conditions which are used for PAGE. Acrylonitrile Monomer used in manufacture of a range of plastics used in packaging materials or other food contact applications. Acrylonitrile residues may migrate out of plastics items and cause contami- nation of foods. F-actin Filamentous actins, formed by longitudinal polymerization of G-actin (globular actin) mono- mers. Two strands of F-actin coil spirally around one another to form the superhelix, which is characteristic of actin myofilaments within myofibrils. Actinidains EC 3.4.22.14. Cysteine endopeptidases (proteinases) found in kiwifruit (Chinese gooseber- ries) with specificity similar to that of papain. One of the major allergens in these fruits. Produced in mi- crobial fermentations as recombinant enzymes for commercial uses, which include tenderization of meat. Also known as actinidins. Actinidins Alternative term for actinidains. Actinomucor Genus of fungi of the family Mu- coraceae. Occur as saprotrophs on decaying vegetable matter, soil or dung, or as parasites or pathogens of plants or animals. Actinomucor elegans and A. tai- wanensis are used in production of East Asian special- ity foods, such as sufu and meitauza. Actinomyces Genus of facultatively anaerobic Gram positive bacteria of the family Actinomycetaceae. Occur as the normal flora of the mouth and throat or as pathogens in humans and cattle. Actinomyces pyo- genes is the cause of summer mastitis in cattle, and can therefore contaminate their milk. Actinomycetales Order of aerobic Gram positive bacteria. Occur in soil, composts and aquatic habi- tats. Most species are free-living and saprophytic, but some form symbiotic associations and others are pathogenic to man, other animals, and plants. Actinomycetes Obsolete name for Actinobacteria, a class of aerobic Gram positive bacteria which oc- cur in soil and water. Some species are used in the production of enzymes (e.g. lipases and cellu- lolytic enzymes). This class also includes some plant and animal pathogens. Actinoplanes Genus of Gram positive, aerobic bac- teria of the family Actinoplanaceae. Occur in soil, plant litter and aquatic habitats. Actinoplanes mis- souriensis may be used in production of enzymes (e.g. glucose isomerases and xylose isom- erases). Actinospectacin Alternative term for the antibiotic spectinomycin. Actins A family of multifunctional intracellular pro- teins, best known as a myofibrillar component of stri- ated muscle fibres. They constitute about 13% of mus- cle proteins and are the major components of the I- band or thin filament of the sarcomere. Actins contain high levels of the amino acid proline. Imino-groups within proline contribute to the folding of actin mole- cules and result in formation of G-actin (globular ac- tin). G-actin, a spherical molecule approximately 5.5 nm in diameter, constitutes the monomeric form of ac- tin. In the presence of potassium chloride and ATP, G- actin polymerizes into long fibres of F-actin. Most ver- tebrate genomes contain numerous actin genes with high sequence homology in protein coding regions, but considerable variability in intron size and number. This genetic diversity can be utilized for livestock speci- ation and meat authenticity tests. Determination of actin content has been proposed as a means of calculat- ing the meat content of meat products. Activated C Alternative term for activated carbon. Activated carbon Amorphous forms of elemental carbon, particularly charcoal, which have been treated, e.g. by acid or heat, to improve their powers of absorption. Used for a variety of food and industrial applications, including drinking water purification, de- coloration of sugar solutions and sorption of residues of pesticides from wines. Activation energy Minimum energy required for a chemical reaction to proceed; the difference in energy between that of the reactants and that at the transition state of the reaction. Activation energy determines the way in which the rate of a reaction varies with tem- perature. 6 Active packaging S-Adenosyl-l-methionine Active packaging Packaging materials which have functions additional to their basic barrier action. Used for packaging a wide range of foods and bever- ages. Types of active packaging include: packs which adsorb ethylene to control ripening of fruits; packs which regulate moisture levels; packs which contain oxygen scavengers; packs which contain CO 2 scavengers or generators; packs which release or absorb flavours or aromas; antimicrobial packaging (e.g. packs which release ethanol to control the growth of fungi); packs with special microwave heating prop- erties; and packaging with monitoring systems (time/temp. exposure indicators or temp. control). Active sites Locations on the surface of catalysts at which reactions occur. On enzymes, substrates are bound at the active sites, the shape of the site being important for strong and specific binding to occur. Actomyosin A complex of the two major muscle proteins, actins and myosin. Actomyosin is formed during muscle contraction with simultaneous hydrolysis of ATP to ADP. Within myofibrils during contraction, each myosin head region on a thick myo- filament attaches to a G-actin molecule within a thin myofilament. This interaction leads to formation of crossbridges between actin and myosin, and to forma- tion of the actomyosin complex. Formation of actomy- osin results in rigidity and lack of extensibility in mus- cles. In the presence of ATP, as in living animals, the actomyosin complex dissociates rapidly; however, post mortem, actomyosin is the dominant form of myofi- brillar protein and it plays a major role in the develop- ment of rigor mortis. During post mortem storage, tenderness of meat is affected by modification of the actin-myosin interaction. Thermal denaturation of actomyosin occurs at temp. between 30 and 50qC. Acylamidases Alternative term for amidases. Acylases Alternative term for amidases and ami- noacylases. Acylation Introduction of acyl groups into a com- pound or substance. Usually achieved by reaction with an acyl halide or carboxylic acid anhydride. Such modification is used to alter the physicochemical properties, functional properties or nutritional quality of substances such as starch, proteins and sugars. Acylglycerols Systematic name for fatty acid es- ters of glycerol, such as monoacylglycerols, diacylglycerols and triacylglycerols. Major com- ponents of natural fats and oils (particularly as tria- cylglycerols); also used as emulsifiers. Synonym for glycerides. Acyltransferases EC 2.3. Enzymes which catalyse transfer of acyl groups from a donor molecule to an acceptor molecule. Includes transferases involved in transfer of amino-acyl groups (EC 2.3.2.-), acyl groups other than amino-acyl groups (EC 2.3.1.-), and acyl groups that are converted to alkyl groups on transfer (EC 2.3.3.-). Involved in a variety of metabolic path- ways, including lipids and sterols. Additives Ingredients added in low quantities to foods during processing for one or more specific purposes. These include prevention of chemical and microbial spoilage, enhancement of flavour or colour, im- provement of nutritional values or as an aid to processing. The most common types of additives in- clude preservatives, colorants, sweeteners, fla- vourings, emulsifiers, thickeners and stabiliz- ers. Adenine Purine, synonym 6-aminopurine. Component base of nucleic acids, nucleosides and nucleo- tides. Adenosine Nucleoside of adenine and ribose, syno- nym adenine riboside. Constituent of nucleotides and nucleic acids. Adenosine diphosphate Phosphorylated adenoside derivative, and breakdown product of the nucleotide adenosine triphosphate (ATP). Level may be used as an indicator of freshness in foods such as meat and fish. Usually abbreviated to ADP. Adenosine monophosphate Nucleotide formed by breakdown of nucleic acids, adenosine triphos- phate (ATP) or adenosine diphosphate (ADP). Level may be used as an indicator of freshness in foods such as meat and fish. Commonly abbreviated to AMP. Adenosinetriphosphatases Alternative term for ATPases. Adenosine triphosphate Nucleotide which is im- portant in energy metabolism. Ratios of adenosine triphosphate to its decomposition products may be used as indicators of freshness in foods such as meat and fish . Levels may also be used as an indica- tor of microbial counts in foods. Commonly abbrevi- ated to ATP. S-Adenosyl- L -methionine One of the coenzymes involved in methyl group transfer. Plays an important role in several human metabolic pathways. Even though it is synthesized in the liver, relatively low lev- els are found in individuals suffering from coronary heart diseases, Alzheimer's disease, liver cir- rhosis and depression. This has lead to its use as a food supplement and its potential application as an ingredi- ent of functional foods. Not widely available in the diet. Produced during fermentation of various micro- organisms, including Bifidobacterium bifidum and Kluyveromyces lactis. 7 Adenoviruses Adsorption Adenoviruses Double stranded DNA-containing viruses of the genus Mastadenovirus and family Adenoviridae which can infect mammals and birds. Infection of humans, which can occur via ingestion of faecally contaminated water or shellfish, can cause gastroenteritis. Adherence Binding of microorganisms specifi- cally or non-specifically to a substratum or to other cells. May be mediated by specialized microbial com- ponents or structures (e.g. adhesins and prostheca). Adherence to a particular host tissue is a preliminary stage in pathogenesis for many pathogens. Adhesins Bacterial cell surface appendages or ex- tracellular macromolecular components that facilitate adherence of a cell to a surface or to other cells. Im- portant in the colonization of mucous membranes, e.g. the intestinal mucous membranes by enteropathogenic Escherichia coli. Also facilitate adherence of bacte- ria to surfaces such as glass, ceramics and synthetics. Adhesion Attachment and sticking together of one or more substance. Adhesives may be used to promote adhesion, e.g. in packaging materials. Sometimes used to refer to adherence of microorganisms to a substratum or other cells. This may be mediated by specialized microbial components or structures such as adhesins or prostheca. This type of adhesion is im- portant for the action of the microorganism, e.g. a pre- liminary step in pathogenesis of pathogens. Adhesives Substances used to stick items together. Most adhesives form a bond by filling in the minute pits and fissures normally present even in very smooth surfaces. Effectiveness of an adhesive depends on sev- eral factors, including resistance to slippage and shrinkage, malleability, cohesive strength, and surface tension, which determines how far the adhesive pene- trates the tiny depressions in the bonding surfaces. Adhumulone Į-Acids fraction of the bitter com- pounds of hops. ADI Abbreviation for acceptable daily intake. Adipic acid Synonym for hexanedioic acid. Used in acidulants, antimicrobial preservatives or starch- modifying agents. Adipic acid esters are used as plasticizers in plastics. Adipocytes Cells found in adipose tissues. These cells are specialized for the synthesis and storage of fat (lipid) globules. The fats are usually stored in the form of triglycerides and serve as a source of en- ergy. Also known as fat cells. Adipogenesis The formation of adipose tissues. Also called lipogenesis. Adiponectin One of the hormones produced and secreted by adipocytes. Regulates metabolism of lipids and glucose. Adipose tissues Connective tissues which func- tion as an energy reserve and insulation layer com- posed of cells (adipocytes) which synthesize and store large lipid globules. Adjunct cultures Non-starter cultures used in addi- tion to starters, mainly in cheesemaking, to pro- duce a specific benefit, e.g. smoother texture, im- proved flavour or accelerated ripening of cheese. In production of yoghurt, adjunct cultures have been used to manufacture products with increased levels of nutrients such as folates. Adjuvants Ingredients added to a mixture to improve the effectiveness of the primary ingredient. For exam- ple colour adjuvants are used to enhance food colour. Adlay Alternative term for Jobs tears. ADP Abbreviation for adenosine diphosphate. ADP-glucose pyrophosphorylases Alternative term for glucose-1-phosphate adenylyltrans- ferases. ȕ-Adrenergic agonists Group of non-hormonal growth promoters. Used to enhance growth rates and improve feed efficiency and lean meat content of animals; also used in veterinary medicine as bron- chodilatory and tocolytic agents. In general, rapidly excreted from the body; non-authorized use during withdrawal period has resulted in cases of human food poisoning. Banned for use as growth-promoting agents in farm animals in many countries, including European Union member states and the USA. Com- monly used examples are clenbuterol and racto- pamine. Adsorbents Substances that are capable of adsorp- tion. Used widely in the food and biotechnology in- dustries. Uses include removal of unwanted materials in foods and beverages that affect either food safety or food quality. Examples include removal of proteins from white wines, pathogens from drinking wa- ter sources, radioelements from foods, oxidation products from frying oils allowing oil recovery and reuse, and bitter compounds from fruit juices. Other applications include: for isolation of compounds with potential use in foods; in the immobilization of enzymes; as agents in analytical techniques such as gas analysis and chromatography; and for re- moval of unwanted aroma and flavour in packaged foods. Adsorption Adhesion of the molecules of liquids, gases and dissolved substances to the surfaces of sol- ids, in contrast to absorption, in which the molecules actually enter the medium. Adsorption is employed in hydrogenation of oils, in gas analysis, and in chromatography. 8 Adulteration Aflatoxin B2 Adulteration Addition of substances to foods, or sub- stitution of food ingredients with inferior substances, with the intent of lowering the quality and costs of producing the food and defrauding the purchaser, e.g. addition of starch to spices, and of water to milk or beer. Adzuki beans Common name for seeds produced by Vigna angularis, also known as azuki beans. Small red beans with a mild, sweet flavour, which are widely cultivated in Japan and China. Traditionally consumed boiled, ground into meal or used to make sweet bean pastes known as ann or an. Seeds may also be germi- nated to produce bean sprouts. Aerated confectionery Confectionery produced with incorporation of air as an ingredient. Use of air adds bulk to the product without increasing its weight, improving product texture and flavour. Aeration of confectionery results in a range of products with densi- ties ranging from 0.2 to 1.0 g/cm 3 . Such products in- clude chews, mallows, honeycomb and meringues. Aeration Introduction of air into a product to enhance texture, mouthfeel, rheology and visual appeal. The following methods are used to aerate foods: fer- mentation; whipping or shaking of low-medium viscosity liquids; mixing of doughs or high viscosity pastes, in which air bubbles are entrapped as surfaces come together; steam generation during slow to mod- erate cooking, baking or frying; entrapment of air between sheeted layers, as in pastries and crois- sants, or between pulled strands, as in pulled taffy and candy; frying in very hot oils, such that internal steam rapidly forms, causing the product to puff; use of chemical raising agents such as baking pow- ders or sodium bicarbonate; rapid dry heating of small or thin products to induce blistering or slight puffing; gas injection (e.g. air, carbon dioxide, ni- trogen and nitrous oxide); expansion extrusion; pressure beating (dissolution of air or gas under pres- sure in a syrup, fat mixture or chocolate); puffing, in which products such as breakfast cereals containing superheated moisture are subjected to a sudden release of pressure; and vacuum expansion, followed by rapid cooling to set the expanded products. Aerobacter Obsolete genus of Gram negative, rod- shaped bacteria of the family Enterobacteriaceae, the species of which have now been reclassified into the genera Enterobacter and Klebsiella. Aerobes Organisms that require atmospheric oxygen to live. Often refers to aerobic bacteria or other mi- croorganisms. Facultative anaerobes are aerobes that can also grow under anaerobic conditions. Aerococcus Genus of Gram positive, coccoid lactic acid bacteria of the family Aerococcaceae. Aerococ- cus viridans has been isolated from a variety of foods, particularly fish and fermented foods, and may also be used in the production of lactate 2- monooxygenases. Aerolysins Cytolytic toxins secreted by Aeromo- nas hydrophila. Form channels in cell lipid bilayers, leading to destruction of the membrane permeability barrier and osmotic lysis. Aeromonas Genus of facultatively anaerobic, rod- shaped Gram negative bacteria of the Aeromo- nadaceae family. Occur in salt and fresh water, sewage and soil. Aeromonas hydrophila, frequently found in fish and shellfish and occasionally in red meat and poultry meat, may cause septicaemia, meningitis and gastroenteritis in humans. Aerosol packs Containers for pressurized liquids, which are released in the form of a spray or foam when a valve is pressed. Aerosol propellants, usually lique- fied gases, are used in the packs. Used as dispensers for a variety of foods. Aerosols Substances, including foods, stored under pressure in a container (for example in aerosol cans) containing a propellant and released as a fine spray or froth. Also, in a chemical sense, suspensions of submi- croscopic particles dispersed in air or gas. Afalon Alternative term for the herbicide linuron. Affination The first stage in processing of raw sugar, in which the layer of mother liquor surrounding the crystals is softened and removed. Raw sugar is mixed with a warm, concentrated syrup of slightly higher pu- rity than the syrup layer so that it will not dissolve the crystals. The resulting magma is centrifuged to sepa- rate the crystals from the syrup, thus removing the greater part of the impurities from the input sugar and leaving the crystals ready for dissolving before further treatment. The liquor which results from dissolving the washed crystals still contains some colour, fine parti- cles, gums and resins, and other non-sugars. Affinity chromatography Chromatography tech- nique in which an immobilized ligand is used to retain an analyte that is later eluted under conditions where the binding affinity is reduced. The ligand, which may be a substance such as an enzyme, hormone or antigen, is bound to a matrix such as silica. Aflatoxicosis Mycotoxicosis caused by ingestion of aflatoxins in contaminated foods or feeds. Aflatoxin B 1 Potent hepatotoxic, hepatocarcinogenic, mutagenic and teratogenic mycotoxins produced by Aspergillus flavus and A. parasiticus. Formed during growth on a wide range of crops, including peanuts, corn and other cereals, and oilseeds. Metabolized to aflatoxin M 1 and aflatoxin Q 1 . Aflatoxin B 2 Moderately potent hepatotoxic, hepato- carcinogenic, mutagenic and teratogenic mycotoxins 9 Aflatoxin B3 African yam beans produced by Aspergillus flavus and A. parasiticus. Dihydroxy derivatives of aflatoxin B 1 . Formed dur- ing growth on the same commodities as aflatoxin B 1 (including peanuts, corn and other cereals, and oilseeds), but in smaller amounts. Metabolized to aflatoxin M 2 , and excreted in milk in this form. Aflatoxin B 3 Toxic mycotoxins produced by older cultures of Aspergillus parasiticus and A. flavus. Al- ternative name for parasiticol. Aflatoxin D 1 Carboxylated product of aflatoxin B 1 , produced by the reaction between aflatoxin B 1 and heated ammonium hydroxide. Possesses lower toxic- ity than aflatoxin B 1 . Aflatoxin G 1 Potent carcinogenic and genotoxic my- cotoxins produced by Aspergillus parasiticus. Formed during growth on a wide range of crops, in- cluding peanuts, corn and other cereals, and oil- seeds. Possess toxicity and structure similar to those of aflatoxin B 1 . Aflatoxin G 2 Mildly carcinogenic and genotoxic my- cotoxins produced by Aspergillus parasiticus. Oc- cur in a wide range of foods, including nuts, seeds, beans, spices and fruits. Dihydroxy derivative of aflatoxin G 1 , with lower toxicity. Aflatoxin M 1 The toxic, 4-hydroxy derivative of afla- toxin B 1 , found in the livers, kidneys, blood, faeces, urine and milk of mammals that have consumed afla- toxin B 1 contaminated feeds or foods. Subsequently occurs in dairy products, particularly cheese, and human milk. Produced in small quantities by As- pergillus flavus and A. parasiticus, and can occur in corn, nuts and soybeans. Associated with liver damage and cancer. Possesses lower toxicity than aflatoxin B 1 . Aflatoxin M 1 can be degraded by UV ra- diation. Aflatoxin M 2 The toxic, 4-dihydroxy derivative of aflatoxin B 2 , found in the livers, kidneys, blood, faeces, urine and milk of mammals that have con- sumed aflatoxin B 2 contaminated feeds or foods. Also occurs in human milk. Aflatoxin M 2 is considerably less toxic than aflatoxin M 1 . Produced in small quan- tities by Aspergillus flavus and A. parasiticus. Aflatoxin P 1 Demethylated and hydroxylated product of aflatoxin B 1 , and the principal urinary metabolic product found in animals. Considerably less toxic than aflatoxin B 1 . Aflatoxin Q 1 The 3-hydroxy derivative and major me- tabolite of aflatoxin B 1 in humans, rats and primates. Considerably less toxic than aflatoxin B 1 . Aflatoxins Mycotoxins produced by certain strains of Aspergillus, most notably A. flavus and A. para- siticus. Formed during growth of these fungi on com- modities such as cereals (e.g. corn), nuts (e.g. peanuts) and oilseeds (e.g. soybeans). Con- tamination can take place both pre- and postharvest. Host crops are particularly susceptible to infection following prolonged exposure to high humidities or damage during drought conditions. Once ingested, aflatoxins are metabolized by the liver to a reactive in- termediate, aflatoxin M 1 . Hepatotoxic and hepatocar- cinogenic in humans and animals, and can result in aflatoxicosis. African breadfruit seeds Kernels of fruits pro- duced by the tree Treculia africana. Eaten roasted as nuts or ground into meal which is used to fortify foods or to prepare porridges. African locust beans Seeds produced by Parkia filicoidea or P. biglobosa. Not eaten raw, but fer- mented to produce food flavourings or protein-rich iru or dawadawa. The yellowish pulp surrounding the seeds can also be eaten, either raw or as an ingredi- ent in soups, stews and beverages. African mangoes Common name for the African tree species, Irvingia gabonensis. Also known as bush mango or wild mango. Fruits resemble cultivated mangoes, but they are botanically unrelated. Pulp of the fruit is eaten fresh or used for the preparation of products such as juices and jams. African mango seeds, also known as dika nuts, have a variety of food uses. African mango seeds Seeds from the tropical African tree Irvingia gabonensis which are rich in fats and are used in Africa to make dika bread as well as a type of butter. Alternative term for dika nuts. African nutmeg Seeds of the African tree, Monodora myristica. Used as spices in Nigeria and other parts of Africa. African oil beans Edible oilseeds of the legumi- nous tree Pentaclethra macrophylla, native to tropical Africa. Cooked seeds are fermented to produce ugba. African spider herb Common name for Cleome gynandra, also known as cat's whiskers. The plant grows wild in most tropical countries, and is mainly consumed as a leafy vegetable. Leaves are a rich source vitamin A, vitamin C and minerals such as calcium and iron. Leaves also contain glucosi- nolates and phenols, which can impart astrin- gency. African yam beans Beans produced by Sphenostylis stenocarpa. Popular grain legume of West Africa and other areas of tropical Africa. Beans have a distinctive flavour and are high in starch and moder- ately high in proteins. Prolonged cooking time is rec- ommended to inactivate antinutritional factors pre- sent in the beans. The plant also produces edible tu- bers. 10 Aftertaste Agmatine Aftertaste A flavour, often unpleasant, that lingers in the mouth after a food has been swallowed. Afuega'l Pitu cheese Unpasteurized Spanish cheese usually made mainly from cow milk. Fresh red chillies are added to the cheese and more are rubbed into the rind as the cheese is allowed to mature, giving the rind a buff to deep orange colour. The rind also has a dusting of white mould. Agar Extract obtained from various species of red seaweeds belonging to Eucheuma, Gelidium and Graciliria genera. Contains agarose and agaropectin polysaccharides. Sets following dissolution in warm water to form agar gels, which are widely used as thickeners and stabilizers in the food industry. Additionally used in gelling agents to prepare cul- ture media for bacteriological plate counts. Also known as agar-agar. Agar-agar Alternative term for agar. Agarases Enzymes, often produced by marine bac- teria, including Į-agarases (EC 3.2.1.158) and ȕ- agarases (EC 3.2.1.81). Į-Agarases are derived from organisms such as Thalassomonas spp., and catalyse endohydrolysis of 1,3-Į- L -galactosidic linkages in agarose, forming agarotetraose as the major product. ȕ-Agarases cleave the 1,4-ȕ- D -galactosidic linkages in agarose in a random manner, forming the tetramer as the predominant product. Polysaccharides formed have potential for use in foods. Both enzymes are also able to hydrolyse porphyran. Agar gels Gels formed by dissolving agar in water. Widely used as thickeners and stabilizers, e.g. in ice cream, soups, jellies, sauces, glazes and meat products. Agaricus Genus which includes some edible fungi, such as the widely cultivated common mushroom, Agaricus bisporus, which is sold commercially in flat, cup or button forms. Other edible species include the wild mushrooms A. campestris (field mushroom) and A. arvensis (horse mushroom). Agaritine Genotoxic substance present in raw mush- rooms. Agarose Purified gelling fraction of agar, a complex polysaccharide produced by algae of the class Rhodo- phyceae. Agarose is a neutral, linear polymer com- posed of alternating ȕ- D -galactopyranose and 3,6- anhydro-Į- L -galactose sugars. Used as a matrix in gel electrophoresis for the separation of large molecules such as DNA, as well as in purification of fermentation products such as enzymes. Agastache A genus of herbs to which several spe- cies belong, most of which are native to North Amer- ica. The leaves may be used as flavourings or to pre- pare herb tea. Agastache rugosa (Korean mint) has a minty flavour and aroma, whilst A. foeniculum (an- ise hyssop) tastes like liquorice. Agave Plants of the genus Agave, the flowers, leaves, stalks and sap of which are used as a source of food or beverages. Starch in buds is converted into sugar causing a sweet nectar to be exuded from the flowers. Sap is used to make a refreshing beverage or can be boiled to make sugar syrups. Fermentation of the sap produces vinegar or the alcoholic beverage pulque. Fermented sap from A. tequilana is distilled to make tequila. Ageing Process in which properties change over time. Ageing includes the intentional storage of foods and beverages to induce desirable changes in sensory properties, such as for wines and cheese (also re- ferred to as ripening). The term is also used to denote the artificial hastening of this process, such as treat- ment of flour with ammonium persulfate to produce a more resilient dough. Agglomerates Masses or collections of particles or items. Agglomeration The process by which particles or items are collected together and formed into a mass. Agglutination The clumping together of cells, such as bacteria, due to cross-linking by proteins such as an- tibodies. Agglutination is utilized in immunologi- cal techniques for detecting bacteria in foods. In food processing, however, agglutination of starters , such as those used in the manufacture of dairy prod- ucts including certain cheese varieties, can have det- rimental consequences for the process outcome. Agglutination tests Immunological techniques in which antigens on the surface of particulate mate- rial, such as bacteria, or inorganic particles, such as latex, are precipitated with antibodies. Antibodies react with the antigens causing the cells to clump to- gether and form visible aggregates or agglutinates. Applications include detection of Escherichia coli O157:H7. Agglutinins Substances, such as antibodies and lectins found in plant seeds, which cause agglutina- tion of cells to form clumps. Aggregation The process for forming a whole by combining several different elements or items. Agitation The process of stirring, shaking or disturb- ing briskly, particularly applied to a liquid. Aglycones The part of a glycosides molecule which is not a sugar residue, e.g. the anthocyanidins com- ponent of anthocyanins. Agmatine One of the biogenic amines, which oc- curs in a wide range of foods, including fish, cheese and alcoholic beverages. Concentrations in foods may increase with increasing storage time. [...]... with acesulfame K to give a more sugar-like taste and to increase potency Aspartate aminotransferases Alternative term for aspartate transaminases Aspartate transaminases EC 2.6.1.1 Also known as aspartate aminotransferases One of the transferases, this enzyme catalyses the reaction of the amino acid L-aspartic acid with 2-oxoglutaric acid to produce oxaloacetic acid and L-glutamic acid Also acts on... known as arabans -N-Arabinofuranosidases EC 3.2.1.55 These glycosidases hydrolyse terminal, non-reducing -Larabinofuranoside residues in -L-arabinosides Release arabinose from -L-arabinofuranosides, -Larabinans containing (1,3 )- and/or (1,5)-linkages, arabinoxylans and arabinogalactans Occur naturally in plant foods including fruits and cereals, where they are involved in the degradation of pectins and... use Amaranth grain Seeds from plants of the genus Amaranthus, which are high in starch, proteins, lysine and minerals Also known as grain amaranth Amaranth starch Starch extracted from amaranth grain Most commonly utilized in parts of South America, Africa and Asia where amaranth is cultivated as a food crop Amaranthus Genus of dicotyledenous plants of the family Amaranthaceae Certain species of Amaranthus... Usually, alligator meat is trimmed heavily of fat because the fat has an unpleasant flavour Each carcass includes both light and dark meat In comparison with free-range alligator farming, indoor farming may be associated with an increased prevalence of salmonellae Due to biomagnification, alligators living in polluted areas can accumulate substantial concentrations of heavy metals Alligator pears Alternative... sativa, also known as lucerne, generally grown as a fodder plant, although young leaves and alfalfa sprouts can be used as a vegetable, e.g in Chinese cooking Alfalfa seeds Seeds produced by alfalfa (Medicago sativa) which are germinated to make alfalfa sprouts for human consumption Sprouts are generally eaten raw in sandwiches and salads Alfalfa sprouts Crisp sprouts obtained by germination of alfalfa... bacteria have been used to catalyse isomerization of Dgalactose to D-tagatose, a low-calorie sugar Arabinosidases Alternative arabinofuranosidases term for -N- Arabinoxylans Polysaccharides in which the main constituent sugars are arabinose and xylose Form part of the pentosans fraction in cereals and cereal products, and may be of importance for technological properties in processes such as baking and... Pseudoterranova larvae have also been implicated as causative organisms Also known as anisakidosis Anisakidosis Alternative term for anisakiasis Anisakis Genus of parasitic nematodes of the family Anisakidae Anisakis simplex has been implicated in anisakiasis, an infection caused by consumption of contaminated raw or undercooked sea foods Anisaldehyde Common name for pmethoxybenzaldehyde One of the flavour... the aromatic amino acids L-tyrosine, L-phenylalanine and L-tryptophan Raised plasma Aspartic acid levels of these enzymes are indicative of hepatic damage, and thus may be measured to investigate the hepatotoxicity of a substance Aspartic acid One of the non-essential amino acids, occurring in most food proteins Aspartyl phenylalanine methyl ester Systematic name for aspartame Aspergillic acid Antifungal... N-acyl-DLamino acids Can also be used for acylation of amino acids in organic solvents Aminobenzoic acid Aromatic acid used in antimicrobial preservatives for use in foods 2-Aminobutane butylamine Alternative term for (RS)-sec- Aminobutyric acid Member of the organic acids, this organic nitrogen compound encompasses 4 struc- 1-Aminocyclopropane-1-carboxylate synthases EC 4.4.1.14 Catalyse the rate-limiting... Oriental pears or Japanese pears 32 Aspartate transaminases Asparaginases EC 3.5.1.1 Hydrolases which catalyse the conversion of L-asparagine to L-aspartic acid and ammonia Involved in metabolism of amino acids in vivo Potentially useful for reducing the acrylamide content of cooked foods, through removal of asparagine which is a precursor of this toxin Asparagine One of the non-essential amino acids, . agar-agar. Agar-agar Alternative term for agar. Agarases Enzymes, often produced by marine bac- teria, including Į-agarases (EC 3.2.1.158) and - agarases. polluted areas can accumulate substantial concentrations of heavy metals. Alligator pears Alternative term for avocados. Alligators Large semi-aquatic predatory

Ngày đăng: 23/10/2013, 18:20

Từ khóa liên quan

Tài liệu cùng người dùng

Tài liệu liên quan