Resources and research

FOCUS ON KAKADU PLUM

Kakadu plum is the most common name for this fruit, although it is found from the Kimberley to Darwin and in Queensland. Other names, depending on location, include gubinge, gabiny, kabiny, mardorr, murunga, bush plum, billygoat plum and salty plum.

The pale olive-green, ovoid fruit has a central wooden stone, similar to an immature olive, and is fibrous with a tart and bitter taste.

Kakadu plum is considered a gift of the Dreamtime by Aboriginal culture and has been an important bush food for millennia for people in northern Australian.

KAKADU PLUM: THE MOST VITAMIN C-RICH FRUIT ON THE PLANET?

Australia is home to one of the most potent vitamin C foods known as the Kakadu plum. How much vitamin C does this superfruit contain? According to the Australian Government’s Rural Industries Research and Development Corp., the Kakadu plum has the “highest recorded level of natural vitamin C content of any plant in the world — more than 100 times that of oranges.”

NATIVE AUSTRALIAN FRUITS – A NOVEL SOURCE OF ANTIOXIDANTS FOR FOOD

Twelve native Australian fruits, finger lime (red and yellow), riberry, brush cherry, Cedar Bay cherry, muntries, Illawarra plum, Burdekin plum, Davidson’s plum, Kakadu plum, Molucca raspberry and Tasmanian Pepper, were investigated for their antioxidant capacity and presence of phenolic compounds, anthocyanins and ascorbic acid.

The radical scavenging activities of five of the evaluated fruits were significantly higher (3.1 to 5.2-fold in the TEAC assay and 1.2 to 4.2-fold in the PCL assay, respectively) than that of the control blueberry, cv. Biloxi. The total phenolics level (Folin–Ciocalteu assay) in six of the twelve fruits was 2.5 to 3.9-fold of that of blueberry.

Kakadu plum was identified as the richest source of ascorbic acid (938-fold of that of control). A high correlation between total phenolics (but not anthocyanins) and antioxidant capacity was observed. The HPLC-DAD/ESI/MS-MS profiles revealed simple anthocyanin composition (one to four individual pigments) with cyanidin as the dominating type.

Australian native fruits investigated in this study are shown to be a novel rich source of antioxidant compounds.