According to the authoritative Memory Alpha Star Trek wiki   the tulaberry was a blue fruit native to the Gamma Quadrant and the main ingredient in tulaberry wine, a blue alcoholic beverage produced, as you very well know, by several Gamma Quadrant races such as the Dosi and the Karemma.

For true believers, “In 2370, Grand Nagus Zek explained to Quark that tulaberries were the key to establishing a Ferengi presence inside the Gamma Quadrant and asked Quark to negotiate a contract for tulaberries with the Dosi. However, Zek later admitted that he was using the tulaberry trade to learn the secret of the Dominion, which he believed was the true key to profit in the Gamma Quadrant. ”

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For ordinary visitors to Tulaberry Farm, we can assure you that most of our daily life is grounded in earthly reality.