I seem to remember that it was also a switch to a different citrus fruit which had way less vitamin C in it so the processing was much mroe important. However,

I seem to remember that it was also a switch to a different citrus fruit which had way less vitamin C in it so the processing was much mroe important. However, since the switch corresponded to the rise of steam power (ship trips were much faster), nobody noticed that that they weren't protected from scurvy anymore. It wasn't until the artic expeditions that scurvy protection got tested again.