The process, which was presented at the National Meeting of the American Chemical Society in Salt Lake City, could cut costs for manufacturers looking to develop this type of beverage, said the scientists.
Heqin Xing and Xiuqi Liu of Jilin University in Changchun, China, said their process works by fermenting the vegetable juice using lactic acid bacteria. The fermentation process reduces the sugar content of the vegetable juice by transforming carbohydrates into lactic acid, they explained.
This is a cheaper process compared to traditional purification methods, and is also an easier way to make the product suitable for diabetics, claim the scientists.
“In the past, people often used the purification method to achieve the effect of treatment. Its price was expensive and the [technology] was complex. Using our method, it can reduce the cost and achieve the same effect.”
In addition, juices produced via purification may contain carbohydrates unsuitable for diabetics, said the researchers.
Acidity and flavor
Xing and Liu used two species of lactic acid bacteria (L.acidophilus, L.plantarum) for fermentation of mixed vegetable juice. These, they said, produced the best results out of all cultures tested, including more lactic acid production and pH reduction.
The use of these cultures in the vegetable juice increased its acidity by 10-fold after 12 hours of fermentation, said the scientists.
"The viable cell counts of L. plantarum in the fermented mixed vegetable juice still remained at up to 5 billion colony forming units per teaspoon after four weeks of cold storage," Xing said.
"The process significantly removes sugar but retains the nutritional content of the juice's raw materials," added Liu.
In addition, the acidity from the fermentation is also said to enhance the flavors of the beverage. The researchers expect the method to be available on the market within around a year, further to some additional testing.