Fruts are similar to pitayas (also known as 'Dragon Fruit') and grow in the jungles surrounding Terra Nova. Some of the local teens in the Terra Nova settlement coined the name "fruts" as the fruit resembles both fruits and nuts.
Fruts were used to make homemade moonshine by Skye and her friends. They can also be seen in the colony and can apparently be eaten before fermentation. ("Genesis") Apparently they can also be used to make paint. ("Vs.")