فرهنگ لغات صنایع غذایی - A - قسمت چهارم

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.