| 释义 |
diastase Chem.|ˈdaɪəsteɪs|
[a. mod.F. diastase, ad. Gr. διάστασις separation: see next.
1833Payen et Persoz Ann. Chim. et Phys. LIII. 76 Cette singulière propriété de séparation nous a determinés à donner à la substance qui la possède le nom de diastase qui exprime précisément ce fait.]
A nitrogenous ferment formed in a seed or bud (e.g. in barley and potatoes) during germination, and having the property of converting starch into sugar.
It is obtained as a white amorphous substance, of unknown analysis (Watts Dict. Chem.). It is found throughout the vegetable kingdom, in the infusoria, and in various secretions, etc., in the higher animals (Syd. Soc. Lex.).
1838T. Thomson Chem. Org. Bodies 666 Diastase..is a name given by MM. Payen and Persoz, to a substance which they extracted from malted barley. 1846J. Baxter Libr. Pract. Agric. (ed. 4) I. 19 During the germination, some of the elements..in the grain form a fresh compound, which acts as a ferment. This compound is called..diastase, the effect of which is..to turn all the starch..first, into gum, and then into sugar. 1863–72Watts Dict. Chem. II. 319 Neither potatoes nor cereals contain diastase before germination. 1894Lancet 3 Nov. 1045 An extremely active poison, delicate, resembling the diastases or venoms.
Hence diaˈstasic, a. = diastatic.
1886W. Jago Chem. Wheat 128 The bacteria cause more or less change in albuminoids, but exert no diastasic action. |