It's all your grandmother's fault. Remember how she planted them in the garden bed? And they grew and grew and watched how she, in between watering, took up knitting needles and balls to knit a scarf and a hat for you for the winter. So now, when you chew them, they remember your granny and knit right in your mouth. This is a special concern, comprehensible only to those who claim to be the compote. But that's nothing, if you live in a village, then the fruits in your mouth will not only be tied, but they will also sing songs to the sound of an accordion. And if you're lucky, the cow will be milked. So you already have a full-fledged agriculture inside of you, and you didn't know about it, can you imagine?
In such fruits, like persimmons, there are tannins (tannins) that come into contact with the cells of the mucous membrane of our mouth during meals. There are proteins in the cell membrane that fold when exposed to tannin. Hence the unusual sensations in the mouth.