“Bhikkhus, how do you conceive it: is form permanent or impermanent?” — “Impermanent, venerable Sir.” — “Now is what is impermanent painful or pleasant?” — “Painful, venerable Sir.” — “Now is what is impermanent, what is painful since subject to change, fit to be regarded thus: ‘This is mine, this is I, this is my self’”? — “No, venerable sir.”—SN 22.59
Impermanence is instrumental in the following two characteristics of existence because every conditioned thing is changing according to the cycle of birth, growth, maturity/ decline, ageing, death. Taking what they see to be permanent, beings form an attachment. This attachment to the object as first seen remains, but those objects age, causing a disjoint between perception and reality, producing sorrow and suffering in the beholder.
The craving for things at their ripest stage in the cycle of impermanence is connected with the primal instincts for survival, so to be overcome the asavas require application of appropriate attention (SN 46.51, Ahara sutta- Food)
The ripe apple as the peak of the cycle is an important motivator in western culture, not only in the Adam & Eve story, but also the Apple company, for opposite reasons in each.
In the Buddhist Anapanasati sutta fourth tetrad, contemplation of impermanence leads to dispassion, perhaps its symbol should be an apple core :
"[13] He trains himself, ‘I will breathe in focusing on inconstancy.’ He trains himself, ‘I will breathe out focusing on inconstancy.’ [14] He trains himself, ‘I will breathe in focusing on dispassion [literally, fading].’ He trains himself, ‘I will breathe out focusing on dispassion.’ [15] He trains himself, ‘I will breathe in focusing on cessation.’ He trains himself, ‘I will breathe out focusing on cessation.’ [16] He trains himself, ‘I will breathe in focusing on relinquishment.’ He trains himself, ‘I will breathe out focusing on relinquishment.’
“This is how mindfulness of in-&-out breathing is developed & pursued so as to be of great fruit, of great benefit.”—MN 118