RETROGRADATION
Etymology
Noun
retrogradation (countable and uncountable, plural retrogradations)
Motion in a retrograde manner.
Decline, degradation.
(chemistry) A reaction that takes place in gelatinized starch when the amylose and amylopectin chains realign themselves, largely responsible for bread becoming stale.
The major reason that bread stales is not moisture loss, but rather a process called retrogradation, in which the starch molecules in the bread crystallize.
Source: Wiktionary
Re`tro*gra*da"tion, n. Etym: [F. rétrogradation or L. retrogradatio.
See Retrograde.]
1. The act of retrograding, or moving backward.
2. The state of being retrograde; decline.
Source: Webster’s Unabridged Dictionary 1913 Edition