With their edible water colours and eco-friendly fuel for cars, two groups of Hong Kong students won a science competition that attracted a wide range of innovative entries.
Pupils from MKMCF Ma Chan Duen Hey Memorial College, who came up with the edible paint, won the Invention category of the Hong Kong Student Science Project Competition 2005.
In the Investigation section, Carmel Pak U Secondary School students grabbed the top prize with their 'biodiesel'.
Other entries included an Octopus reader for the blind, an electricity-saving Smart Lamp and a Bluetooth security system - all invented by local secondary school students.
Cherry Yick Ka-chai, a member of the Ma Chan Duen Hey team, said they got the idea for edible water colours from mothers who were worried that their children would eat crayons.
'We never thought that we would win. But we enjoyed the process,' said Ka-chai.
After experimenting with more than 60 vegetables, the five-member group produced nine colours which were fragrant - and delicious. The red colour tasted like purple cabbage and smelled like roses, while the black had a squid flavour with a ginger aroma.