Today in 1948, US Patent 2440276 A was issued, an invention of Abraham Arnold Klein, for his “Brewing Method Using Albedo In Wort.” There’s no Abstract, although in the description it includes this summary:

According to the present invention albedo from fruit of the genus Citrus, particularly from grapefruit or citron, is used instead of, or in addition to, hops in the manufactured beer. I have found that the lupulin of hops has in many cases undesirable effects on the human organism. Furthermore hops deteriorate easily. Albedo from citrus fruit can be used instead of hops and the bitter flavour imparted by it to the wort is of a mild and agreeable character.

So this is essentially using grapefruit or other citrus almost 70 years before Ballast Point Grapefruit Sculpin. But not the whole fruit, or even the rind, the albedo is the white, fleshy inner later in between the thinner, top rind layer and the inside fruit. That spongy material is, according to this patent, used in place of or with hops in the brewing process. I wonder if anybody used this method to produce commercial beer?