In Okinawa, leucaena (Leucaena leucocephala de Wit) has great potential as animal feed for its high protein content, but its use has been limited owing to the presence of mimosine (b-[N-(3-hydroxy-4-pyridone)]-a-aminopropionic acid) which, when ingested, causes diseases in animals. A detoxifying enzyme, mimosinase, was purified from leucaena leaves and cDNA was cloned based on the amino acid sequence. During essential oil production and fiber isolation from alpinia (Alpinia zerumbet ), large volumes of solid and squeezed wastes are produced and subsequently discarded. An extraction protocol to obtain essential oils, dihydro-5,6-dehydrokawain (DDK) and enriched antioxidant phenolic extracts from fresh leaves or rhizomes of alpinia and its waste was developed.