Barry Aumann with his crates of picked Granny Smith apples at his Warrandyte Orchard.
Barry Aumann with his crates of picked Granny Smith apples at his Warrandyte Orchard. Photo: Simon O'Dwyer

How do you like them apples, Pink Lady lovers?

The good old Granny Smith has been picked top of the tree when it comes to being good for the gut and helping address obesity.

Those who prefer a sweeter fruit might find them a bit tart, but a new study has found the green-skinned apple is better than the Fuji, Gala, Golden Delicious at promoting the growth of good bacteria.

The Granny Smith has a high content of non-digestible compounds, including dietary fibre and polyphenols, which ferment in the colon and establish a healthy balance of bacteria, the study said.

Food scientist Giuliana Noratto from Washington University said these bacteria can help prevent obesity and related conditions such as diabetes. They also can provide the feeling of being satisfied. 

"We know that, in general, apples are a good source of these non-digestible compounds, but there are differences in varieties," she said.

"What determines the balance of bacteria in our colon is the food we consume."

Victoria is the home of the Granny Smith, producing about half of all those picked in Australia each year. That equates to about 27,000 tonnes of fruit, grown mainly in the Goulburn Valley and Yarra Valley. 

The apple was first cultivated in Australia in the 1860s and is named after Maria Ann "Granny" Smith, an English immigrant credited with discovering the green apple.

It is the third most popular apple in Australia, after the Pink Lady and Gala, accounting for 18 per cent of all sales.

The owner of the Aumann Family Orchard at Warrandyte, Barry Aumann, said the Granny Smith had lost its popularity in recent years, which he put down to  its tangy flavour.

He said the biggest buyers of Granny Smiths usually were older people who might have grown up with the variety and still used them for cooking.

Believed to have originated from French crab apples, the Granny Smith is considered the go-to cooking apple because of its diminished sweetness. The apple gets sweeter as it matures. 

"With our improved long-term storage, the Grannies come out tasting the same as when they went in. They don't get as sweet as they used to,"  Mr Aumann said.

Apple and Pear Australia CEO John Dollisson said the Granny Smith always had been a popular variety in Australia, with the average apple consumption overall about 8.5 kg per person per year.

He said a recent stall at the Royal Melbourne Show showed the Granny Smith  remained popular with apple eaters, even children, despite their tartness. "Maybe it's the green colour," he said.