Towards a bush berry blueprint


One of Australian native food’s best-kept, and most nutritious, secrets is now an important step closer to large-scale commercial viability, thanks to research undertaken at the University of Adelaide.

There’s a lot to like about muntries. Also known as “muntries berries”, this native fruit grows naturally in parts of South Australia and Victoria, so ticks the low-transport-miles box for many domestic markets. It’s sweet, and does well in taste tests. It can be eaten fresh, dried, made into jams or used in toppings. It’s also good for us. Muntries’ levels of antioxidants, associated with a diverse range of health benefits, are five times higher than that of commercial blueberries.

Indigenous communities in the fruit’s growing areas ate them regularly for centuries. So why aren’t we? The simple answer is a production-knowledge deficit. Growing the modest muntries industry will require farming more varieties, in greater volumes, and delivering consistent size and quality, but the scientific data indicating how best to go about that simply isn’t there.

Research undertaken at the University of Adelaide, however, has taken a vital first step towards formulating a best-practice blueprint. Dr Chi Mai Do, from the University’s School of Agriculture, Food and Wine, recently completed the first detailed study of muntries as part of her PhD, under the supervision of Dr Kate Delaporte. According to Dr Do, her findings—based on fruit collections taken from orchards in Mt Pleasant and McLaren Flat, South Australia, in 2014–2016—produced benchmarking data for muntries research on fruit characterisation, salinity tolerance, and DNA marker development for plant identification and validation.

“Our study shows farmers should definitely be aiming to consistently produce larger berries of more than 12mm in diameter, given that currently the majority of size ranges from 8 to 12 mm in diameter,” she says.

“The larger fruit was shown to be associated with a favourable combination of soluble solids, which is associated with sweetness, and total phenolic content, known to indicate antioxidant capacity. At this size, sweetness is on par with blueberries, and antioxidant levels are five times higher than that fruit.”

Importantly, adds Dr Delaporte, the study—which focuses on muntries variety “Rivoli Bay”, the current industry standard—also appears to indicate key roles for two soil nutrients.

“Sufficient levels of potassium and phosphorous are associated with optimal and consistent fruit size in several other crops, and our results seem to show the same for muntries.

“Our findings also point to a likely correlation between low levels of these nutrients and higher variability in fruit total phenolic content—and therefore antioxidants—within a harvest.”

Although acknowledging further research is needed, the pair believes solid foundations for industry growth have been laid.

“We’d like to see further examination of seasonal fluctuations in potassium and phosphorous concentrations, and the impact of different fertiliser regimes,” says Dr Do. “Then it will be possible to develop best-orchard management practices, and evaluate other muntries varieties relative to the quality benchmarks we’ve established.

“We’re also excited to apply the research process we used—which proved very effective—to more native and bush foods in coming years, like bush tomato, to see if they can become a bigger part of our diets.

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