Development of Low-Calorie Sugars and Functional Jujube Foods Using Biotransformation

Why jujube deserves a second look

Food formulators looking for bulk sweeteners with real functionality should pay attention to jujube. Jujube juice carries a lot of sugar. That sweetness comes mostly from glucose and fructose. The sugar is natural, but it still adds calories. This paper (DOI: 10.1002/fsn3.963) turns that problem around. The authors used enzymes to convert the native sugars in jujube juice into D-allulose, a low-calorie sweetener. They also linked oral D-allulose to metabolic signals that reduce food intake and improve glucose tolerance.

Background

D-allulose is a low-calorie sweetener. This study produced it directly in concentrated jujube juice. That matters. Many enzymatic sugar conversions start from purified syrups. Here, the fruit matrix itself is the substrate.

The conversion relies on two enzymes. D-glucose isomerase converts glucose into fructose. D-allulose 3-epimerase then converts fructose into D-allulose. Because jujube juice already contains both glucose and fructose, the enzyme system can feed on the existing sugar pool.

What the study did

The researchers treated concentrated jujube juice with those two enzymes. They optimized reaction conditions to push the conversion as far as possible. Then they measured how much D-allulose formed and how much glucose and fructose remained.

The work did not stop at chemistry. The paper also reports what happens when D-allulose is given orally. It triggers GLP-1 release and activates vagal afferent signals. Those pathways are central to appetite control and glucose handling.

Key findings

Under optimized conditions, the numbers are practical. D-allulose reached 110 g/L in the concentrated juice. Glucose fell by 13.4%. Fructose fell by 18.1%. The sugar profile shifts. Part of the caloric sugar load becomes a low-calorie sweetener.

Metric	Result
D-Allulose concentration	110 g/L
Glucose reduction	13.4%
Fructose reduction	18.1%
Oral D-allulose effects	GLP-1 release, vagal activation, lower food intake, improved glucose tolerance

The table shows what changed in the juice. It also shows why D-allulose earns the word "functional." This is not just a sugar swap. It is a sweetener that interacts with gut-brain signaling.

What it means for manufacturers

A few practical points jump out.

First, enzyme conversion can happen in a real fruit matrix. You do not need to strip the juice down and rebuild it. That keeps the jujube identity intact, which matters for label claims.

Second, the product carries built-in bioactivity. If you formulate with D-allulose, you can talk about more than sweetness. The paper directly connects D-allulose to GLP-1 release and reduced food intake. That is a strong positioning angle for weight management or blood sugar support products.

Third, the reduction in glucose and fructose is modest but real. A 13.4% drop in glucose and 18.1% drop in fructose will not make a juice low-calorie by itself. But it changes the carbohydrate composition. Combined with the allulose generated, it shifts the product in a meaningful direction.

Buyers should ask suppliers about enzyme specificity, reaction yield, and side-product profile. The study gives a strong starting point at 110 g/L, but commercial scale will depend on your substrate, processing time, and downstream costs.

FAQ

Why use two enzymes instead of one? One enzyme alone cannot make allulose from glucose. The first enzyme converts glucose to fructose. The second enzyme converts fructose to allulose. The two-step route lets the system use more of the existing sugars in jujube juice.

Is 110 g/L allulose commercially relevant? It is a serious concentration. You still need to evaluate your own process economics, but this result gives a solid benchmark. Working in concentrated juice saves water and energy downstream.

Does this work only with jujube? The study uses jujube, but the principle is broader. The approach may extend to other fruit matrices with a mix of glucose and fructose. You need to test your own substrate.

A practical outlook

The paper points to a simple idea. Use the sugars already present in a fruit ingredient to build a low-calorie sweetener. Jujube happens to be a good host. The allulose yield is measurable, the glucose and fructose levels drop, and the final product has a functional metabolic signal. For formulators, that is a rare combination: a fruit-based sugar system that does more than sweeten.