Developing Low-Calorie Sugar and Functional Jujube Foods via Biotransformation

Jujube juice is sweet. That is its selling point and its problem. The sugars in jujube are mostly glucose and fructose. For formulators who want reduced-calorie products, that sugar load gets in the way. A study published in Food Science & Nutrition (DOI: 10.1002/fsn3.963) shows a way to convert those sugars into D-allulose directly inside the juice. The result is a functional jujube ingredient with lower sugar and a built-in sweetener.

Background

Jujube, also called red date, has a strong nutritional profile. It brings fiber, minerals, and antioxidant activity to the table. But its high sugar content limits its use in low-calorie foods. D-allulose is a rare sugar with about 0.2 to 0.4 calories per gram. It tastes like sucrose but does not spike blood glucose. The challenge has always been how to make it efficiently. This paper offers a practical route: use the jujube juice itself as the sugar source and convert those sugars enzymatically.

What the study did

The researchers applied two enzymes to jujube juice: D-glucose isomerase and D-allulose 3-epimerase. These enzymes work together. Glucose isomerase converts glucose into fructose. Allulose 3-epimerase then converts fructose into D-allulose. The team used concentrated jujube juice and optimized the reaction conditions. No external sugar source was needed. The juice already contained the raw material.

Key findings

The numbers are strong. Under optimal conditions, D-allulose reached 110 g/L in the concentrated jujube juice. That is not a trace amount. It is a meaningful concentration for commercial use. At the same time, glucose dropped by 13.4% and fructose dropped by 18.1%. The juice became lower in caloric sugars while gaining D-allulose.

The paper also reports a physiological effect. Oral D-allulose induced GLP-1 release. It activated vagal afferent signals. That combination reduced food intake and improved glucose tolerance in the test model. In plain terms, D-allulose is not just a sweetener. It sends metabolic signals that may help with appetite and blood sugar control.

Parameter	Result	Why it matters
D-allulose concentration	110 g/L	Commercial-level yield from jujube juice
Glucose reduction	13.4%	Lower caloric sugar content
Fructose reduction	18.1%	Lower caloric sugar content
Physiological response	GLP-1 release, vagal activation	Reduced food intake and improved glucose tolerance

What it means for manufacturers

This process turns a commodity ingredient into a functional one. You can start with jujube juice, run an enzymatic step, and end with a product that carries both sweetness and metabolic benefits. That changes the formulation story. Instead of adding D-allulose as a separate ingredient, you create it in situ.

There are practical considerations. Enzyme costs matter. Reaction time and temperature will affect yield. The jujube matrix itself may influence enzyme activity. But the study shows the concept works at a concentration that is useful for food production.

For buyers, this is a sourcing signal. Jujube-based ingredients could soon be positioned as low-calorie sweetening systems rather than just fruit concentrates. That opens doors in beverages, bakery fillings, sauces, and functional foods. Clean label is another angle. Enzymes are processing aids, not final ingredients. The jujube juice remains a recognizable fruit ingredient.

FAQ

Is this process limited to jujube juice?
The study used jujube juice. Other fruit juices with glucose and fructose could work, but you would need to re-optimize enzyme conditions for each matrix.

Is D-allulose produced this way the same as commercial allulose?
Chemically, yes. But the jujube product also contains the natural color, flavor, and bioactive compounds from the fruit. That can be a differentiation point.

Does the jujube product itself produce the same GLP-1 effect?
The paper reports the effect from oral D-allulose. The jujube product contains D-allulose, but you should test the finished ingredient to confirm the effect in your specific formulation.

Closing

Jujube juice already had a nutritional story. Now it has a metabolic one. The enzymatic conversion gives formulators a way to lower sugar and add functionality without rebuilding the ingredient from scratch. That is a useful option to have.