Developing Low-Calorie Sugar and Functional Jujube Foods through Biotransformation

A jujube syrup that does more

Take jujube juice, add the right enzymes, and you get D-allulose. That is what this paper in Food Science & Nutrition (DOI: 10.1002/fsn3.963) demonstrates. The authors worked with concentrated jujube juice and converted its glucose and fructose into the low-calorie sweetener D-allulose. At optimal conditions, the juice reached 110 g/L D-allulose. That is a meaningful number if you buy or formulate sweetener systems.

Background

Jujube juice comes with natural sugars. Those sugars drive sweetness, but they also add calories. The trick is to keep the jujube character and reduce the caloric load. D-allulose fits because it tastes like sugar but does not behave like sugar in metabolism. The paper combines both ideas: biotransformation of jujube sugars into allulose, and the physiology that makes allulose interesting beyond sweetness.

What the study did

The researchers used two enzymes in the juice system: D-glucose isomerase and D-allulose 3-epimerase. They applied them to concentrated jujube juice to convert glucose and fructose into D-allulose. Under optimal reaction conditions, D-allulose concentration reached 110 g/L. Glucose and fructose did not disappear. They dropped by 13.4% and 18.1%, respectively.

The study also looked at what happens after you consume D-allulose. Oral D-allulose induced GLP-1 release, a gut hormone that helps regulate appetite. It also activated vagal afferent signaling, a direct gut-to-brain pathway. In the paper, this led to reduced food intake and improved glucose tolerance.

Key findings

The table below shows the results from the paper.

Measured outcome	Value or effect
D-allulose in concentrated jujube juice	110 g/L
Glucose reduction	13.4%
Fructose reduction	18.1%
GLP-1 release	Induced by oral D-allulose
Vagal afferent signaling	Activated
Food intake	Reduced
Glucose tolerance	Improved

The enzyme step works in a real juice matrix, not just a simple sugar solution. The sugar profile shifts from glucose-heavy and fructose-heavy toward allulose. Those changes make the final syrup lower in calories per gram of sweetness.

What it means for manufacturers

If you produce jujube-based ingredients, this gives you a route to a differentiated product. Instead of selling ordinary jujube syrup, you can offer an allulose-enriched version. The enzymes do the work during processing. The remaining sugars in the juice contribute sweetness and bulk, while the allulose contributes the low-calorie functional character.

For ingredient buyers, this changes how you evaluate jujube syrup. Look for suppliers that can run both enzymes in concentrated juice and verify allulose yield. Ask for process parameters. The 110 g/L figure is your benchmark.

For product developers, the GLP-1 finding matters. A sweetener that triggers appetite-related gut signals gives you room to think beyond plain sugar replacement. This paper adds to the rationale for allulose as more than a bulking sweetener.

FAQ

Q: Does this work with other fruit juices? A: The paper demonstrates the process in concentrated jujube juice. Other juices with glucose and fructose could respond similarly, but you need to test enzyme activity in your specific juice matrix.

Q: What enzymes do I need? A: D-glucose isomerase and D-allulose 3-epimerase. Both work on the sugars in jujube juice and produce D-allulose.

Q: Is allulose just a sugar replacement? A: The study shows a second layer. Oral D-allulose triggers GLP-1 release and activates vagal afferent signaling. That reduced food intake and improved glucose tolerance in the paper.

From paper to production

You do not need to wait for a new crop or a synthetic sweetener. The raw material is already in jujube juice. You just need the enzyme step and the right process. If you are sourcing sweeteners for functional foods, put allulose-enriched jujube syrup on your list. The science shows it works.