| 释义 |
dextrin Chem.|ˈdɛkstrɪn|
Also (less correctly) -ine.
[a. F. dextrine, f. L. dextra right-hand: see -in. Named by Biot and Persoz in 1833, from the optical property mentioned below.
1833Biot & Persoz in Ann. de Chimie et de Physique [2] lii. 72 Nous la nommons dextrine, pour la designer par le caractère spécial que lui donne le sens et l'energie de son pouvoir rotatoire. ]
A soluble gummy substance into which starch is converted when subjected to a high temperature, or to the action of dilute alkalis or acids, or of diastase. Called also British gum, and leiocome.
It has the same chemical composition as starch, but is not coloured blue by iodine, and has the property of turning the plane of polarization 138·68° to the right; whence its name.
1838T. Thomson Chem. Org. Bodies 653 Amidin..caused a deviation of the rays to the right, about three times as great as common sugar—a deviation which is sensibly the same with that of his [M. Biot's] dextrine. 1838Ann. Reg. 374 List of patents, For improvements in the manufacture of dextrine. 1863–72Watts Dict. Chem. II. 313 Dextrin is an uncrystallizable, solid, translucent substance having the aspect of gum arabic..It is employed..for the adhesive layer at the back of postage-stamps. 1870Bentley Bot. 29 If starch be exposed to heat for a prolonged period it is converted into a solid gummy substance, called dextrin or British gum. |