Whole oranges, for sure. I can't see how you'd lose 50% mass if you've already discarded the peel/rind. FWIW, citrus peel is a fairly valuable commodity since

Whole oranges, for sure. I can't see how you'd lose 50% mass if you've already discarded the peel/rind. FWIW, citrus peel is a fairly valuable commodity since it's the raw material for production of limonene, which is a really good and biodegradable degreaser. IIRC it was discovered by NASA searching for a solvent for cleaning the space shuttle.