Freeze-dried fresh onion powder prevents green discolouration (greening) in macerated garlic

► Greening in garlic puree was inhibited by adding freeze-dried fresh onion powder. ► Thiosulphinates containing 1-propenyl are key compounds to induce greening. ► Adding fresh onion powder decreases 1-propenyl thiosulphinate synthesis in garlic. ► New report on inhibition of garlic greening by fresh onion powder.