If I recall correctly, don't the White Pineapples turn a yellowish color when over ripe?
It appears the best method of getting the true variety you want is by ordering a fruit, if possible(usually not possible) and then growing the top. Fortunately for us, the Kuai White Sugarloaf is the best tasting variety I have personally tasted and this fruit can be ordered and delivered directly to your door. Fortunately for my paranoid self, I'm not trusting the mail order nurseries until I've had a chance to fruit their plants and confirm the fruit myself. I'll just have to wait for my White Sugarloaf plantlets from Wellspring Gardens to fruit before I can confirm what I have but in the meantime, I've also got the actual tops of the Kuai White Sugarloafs from Jude growing which I know is the real deal.
Simon