The color of eggplant

[Werdna]

I've never figured this one out, how do some restaurants (seems thai places most often) serve fully cooked, even soft eggplant with skin that's still a bright purple? I just heard someone else asking how a place was making baba ganoush with cooked, pale white-instead-of-brown eggplant. Any tips or techniques?

[nakji]

A Japanese cookbook I have calls for searing the eggplant skin-side down quickly on a hot pan to preserve the colour. I also find that beautiful colour stays bright when I deep-fry my eggplants, so I suspect high heat must be what does it.