Â鶹ÒùÔº

Unlocking the antioxidant power of Australian native fruits

A team from the National Institute of Complementary Medicine at Western Sydney University believe the Kakadu plum and the Davidson plum have the potential to redefine the functional food market globally because of the antioxidant punch they pack—and that power could be harnessed even further in the fermentation process.

Australia's unique native fruits are rich in biologically active compounds and have been used for thousands of years by Indigenous communities to treat various ailments, support nutrition, and maintain health.

They have also been gaining mainstream momentum in recent years as ingredients in dietary supplements, beauty products and gourmet produce—underpinning projections that the Australian bush food industry is set to reach $160 million this year.

However, while native fruits like the Kakadu plum and Davidson plum are incredibly nutrient-dense, in their raw form our upper gastrointestinal tract can absorb less than 10% of the antioxidants they offer.

Dr. Deep Jyoti Bhuyan, a microbiologist and senior research fellow who leads this project at NICM, said working out how to make these antioxidants more "bioavailable," while accurately preserving and promoting Indigenous food sources, was a key focus for his team.

"Our new paper outlines how fermentation by lactic acid bacteria—a group of probiotic bacteria—impacts the nutritional properties of more than 25 fruits and vegetables from around the world," he said.

"We found that the process of fermentation can break down large antioxidant molecules to a size more easily absorbed by our gut. This, in turn, increased our overall absorption of, and ability to access more of, the nutrients in antioxidant-rich foods."

"As a result of these findings, we believe that further investigation of the antioxidant profiles of Kakadu and Davidson plums after fermentation has the potential to add huge value to the emerging Australian bush food sector," he said. The work is in Food Research International.

Fermentation is a complex process where microorganisms like yeast and bacteria break down carbohydrates, such as sugars, without oxygen.

Currently, two types of fermentation co-exist and contribute to a US$52.5 billion global fermented products market: small-scale artisanal fermentation and industrial fermentation. This market is expected to US$78.7 billion by 2032 on the back of changing lifestyles (increased vegetarianism, veganism, and dairy allergies), as well as an increasing interest in nutritional diet therapy.

"The benefits of fermented foods are many—their nutrients are easier for our gut to absorb, and they can support a healthy gut microbiome," said Indeewarie Dissanayake, Ph.D. candidate at NICM and first author of this paper.

"They are also great sources of prebiotic fiber, probiotic microorganisms and biologically active postbiotic molecules, promoting the diversification of gut bacteria and supporting overall health," she said.

NICM director, Professor Dennis Chang, says modern scientific research is now catching up to traditional knowledge, providing some empirical evidence of the health benefits of native remedies.

"The traditional use of Australian native plants and foods as medicine by Indigenous communities is a testament to their profound understanding of the natural environment and its healing properties," he said.