Australasian Science: Australia's authority on science since 1938

Fruit Waste Fights Cancer

By Stephen Luntz

The waste thrown out during the production of fruit juices and other processed fruit products contains antioxidants that may prove potent against disease.

“Fruit has long been known for its health benefits, partly as a good source of antioxidants, the chemical compounds, including some vitamins, that protect body cells from damage,” says Dr Said Ajlouni of the University of Melbourne’s School of Land and Environment. “So we decided to investigate if fruit waste also had these properties.”

Ajlouni and his PhD student Wei Wei Tow heated, froze and bombarded with sound waves the skin and pips from a variety of fruits. In the process they were able to concentrate the already high concentrations of antioxidants in the waste into a powder. Tomato waste started with twice as much lycopene as tomato flesh, and the processing concentrated this three times further.

The fruit waste powders were then tried against cancer cells in vitro, with considerable success. Antioxidant powder made from apple peel waste was the most successful, with 85–98% reductions in the growth of cervical and liver cancer cells.

Ajlouni notes that many previous studies have found evidence that antioxidants in fruit can fight these cancers, but all were based on fruit tissue rather than the peel. He’s also pleased that the chemicals extracted are very resistant to biological degradation.

The findings could prove a double bonus for fruit juice companies. Waste forms a potential source of income if the antioxidant powders can be added to juices without affecting the taste. Moreover, many companies currently have a problem disposing of the waste, with limited success in using it in fertilisers and as animal feed.