Enzymatic Biotransformation of Jujube Juice into Low-Calorie D-Allulose and Functional Food Ingredients

The sugar problem

Jujube juice has a problem. It is rich in glucose and fructose, which makes it hard to use in low-calorie products. A team of food scientists found an enzymatic way out. They converted those sugars directly into D-allulose, a low-calorie sweetener, and published the work in Food Science & Nutrition (DOI: 10.1002/fsn3.963).

Background

Jujube, also known as Chinese red date, is a familiar ingredient in Asian food and beverage applications. It fits the functional food trend well. The catch is the sugar profile. If you remove the sugars from jujube juice, you lose part of the food matrix. The researchers wanted to transform the sugars in place instead. That way, the starting material stays intact while the sweetener profile changes.

What the study did

The team used two enzymes in a cascade. D-glucose isomerase converts glucose into fructose. D-allulose 3-epimerase then converts fructose into D-allulose. The reaction ran directly in concentrated jujube juice. No separate sugar solution was needed. The jujube itself became the production medium.

Under optimized reaction conditions, D-allulose reached 110 g/L. That number matters. It shows a real conversion, not a trace byproduct.

Key findings

The enzyme cascade shifted the sugar profile in a useful direction.

Component	Change	What it means
Glucose	Down 13.4%	Less caloric load from glucose
Fructose	Down 18.1%	Less caloric load from fructose
D-allulose	Produced at 110 g/L	Low-calorie sweetener formed in the juice

The study also tested the physiological effect of oral D-allulose. It induced GLP-1 release. It activated vagal afferent signaling. That gut-brain pathway led to reduced food intake and improved glucose tolerance. So the ingredient is not just sweet. It has a biological function that fits the current metabolic health conversation.

What it means for manufacturers

For ingredient buyers, the interesting part is the direct conversion in fruit juice. You do not need to start with pure glucose or fructose. You can start with a real food ingredient and end with a functional one. Jujube juice with D-allulose could be positioned as a lower-calorie sweetener base, a beverage ingredient, or a component in sugar-reduced bakery and confectionery systems.

The reductions in glucose and fructose are moderate, but they do not have to work alone. D-allulose is the low-calorie sweetener here. It also contributes the GLP-1 effect observed in the study. Together, those properties create a better starting point for formulations aimed at appetite control and glucose management.

The paper does not solve every scale-up question. Enzyme loading, reaction time, and downstream purification still need scrutiny. But the science is clear: biotransformation can turn a high-sugar fruit juice into a lower-calorie functional sweetener.

FAQ

Why use jujube juice instead of plain sugar syrup?

The jujube matrix brings the product into functional food territory. The enzymes work directly in concentrated juice, so the final ingredient is not just allulose. It is a jujube-derived sweetener with the original food base still present.

What does GLP-1 have to do with satiety?

GLP-1 is a gut hormone that helps signal fullness and regulate glucose. The study found that oral D-allulose triggers GLP-1 release and activates vagal afferent signaling. That sequence reduced food intake and improved glucose tolerance in the test model.

Can I formulate with this right now?

The study demonstrates the conversion process and the biological effects. Finished-product data, such as shelf life, texture, and taste in specific applications, still needs to come from your own development work.

The enzyme route gives formulators a concrete way to make low-calorie sugar from a familiar fruit. Jujube no longer has to be either sweet or functional. It can be both. That is a useful option to have on the bench.