1.1.     What Is Allulose? 

Allulose (D-psicose) is a monosaccharide that occurs naturally in small amounts in foods like figs, raisins, and maple syrup. Chemically similar to fructose, it has 70% the sweetness of sucrose but contributes just 0.2–0.4 kcal/g, making it nearly non-caloric. It was first identified in wheat in the 1940s but has gained popularity in recent years due to advances in enzymatic production methods using corn or other plant starches.

1.2. Allulose: Historical Timeline

The turning point came with the advancement of enzymatic epimerization techniques, particularly the use of D-tagatose 3-epimerase enzymes derived from microbial sources.
These enzymes enabled the industrial bioconversion of fructose into allulose using starch-derived feedstocks, unlocking large-scale, cost-effective production. Following the U.S. FDA’s GRAS status approval in 2012, allulose transitioned from academic journals into commercial applications, setting the stage for its adoption in global food manufacturing.

Time lines of “Allulose”

1940s – Discovery

• Initial identification of D-psicose (allulose) in wheat by researchers exploring rare sugars.
• Recognized as a C-3 epimer of fructose, chemically similar but biologically distinct.

1970s–1990s – Academic Exploration

• Studies on rare sugars expand in Japan and Korea, particularly at Kagawa University, under Dr. Ken Izumori’s “Rare Sugar Project.”
• Initial focus: physiological effects, metabolic pathways, and synthetic conversion methods.

Early 2000s – Biotechnological Breakthrough

• Development of enzymatic epimerization technology using D-tagatose 3-epimerase.
• Enables commercial-scale conversion of fructose to allulose using starch-derived feedstocks (e.g., corn).
• Major industrial R&D begins in Japan and the U.S.

2012 – Regulatory Recognition (U.S.)

• The U.S. Food and Drug Administration (FDA) grants GRAS (Generally Recognized as Safe) status to allulose (GRN No. 400).
• Recognized as safe for use in foods and beverages.

2015–2018 – Product Introduction

• Allulose begins to appear inlow-sugar and keto-friendly products in the U.S. and Asia.
• Global awareness increases as consumer demand for sugar reduction intensifies.

2019 – Major Labeling Exemption

• FDA announces that allulose can be excluded from "Total Sugars" and "Added Sugars" on the Nutrition Facts label.
• Game-changing move that accelerates adoption in food formulation.

2020–2023 – Global Expansion

• Approved for use in Mexico, Singapore, and South Korea.
• Market interest surges among functional food, beverage, and sports nutrition brands.

2024–Present – European Regulatory Review & Innovation Acceleration

• European Union begins formal evaluation for Novel Food approval.
• Ongoing innovations in microbial fermentation, strain engineering, and cost-effective production are expanding its viability across multiple regions and applications.

2.1. Functional and Sensory Characteristics

Allulose is structurally similar to fructose but non-metabolizable by the human body, rendering it virtually non-caloric (≈0.2–0.4 kcal/g). Despite this, it retains approximately 70% of the sweetness of sucrose and mimics its physicochemical behaviour in a variety of formulations.

Key functional attributes:

• Thermal stability: Performs well in baked and heat-processed goods.
• Maillard reactivity: Contributes to browning and flavor development.
• Crystallization profile: Similar to sucrose, ideal for confectionery textures.
• Water activity regulation: Enhances shelf life and moisture retention.

These properties allow formulators to partially or fully replace sucrose without compromising taste, texture, or functionality, particularly in bakery, dairy, beverage, and confectionery applications.

2.2. Functional Benefits in Food Applications

Allulose behaves remarkably like sugar in many culinary contexts. 

Its thermal stability, browning capability (Maillard reaction), and mouthfeel make it highly versatile:

• Bakery: Supports bulk and browning in cookies, cakes, and muffins—unlike high-intensity sweeteners that lack functional volume.
• Beverages: Dissolves easily, with no lingering aftertaste, making it ideal for soft drinks and flavoured waters.
• Dairy & Frozen Desserts: Helps depress freezing point, improving scoopability and texture in low-sugar ice creams.
• Confectionery: Works well in caramels and chewy candies thanks to its sugar-like crystallization properties.

3.1. Nutritional and Metabolic Profile

Allulose stands out among alternative sweeteners due to its unique absorption and metabolic pathway. Unlike traditional carbohydrates such as glucose or fructose, allulose isabsorbed in the small intestine but is not metabolized for energy. Instead, it is excreted unchanged through the urine, contributing a negligible amount of calories—approximately 0.2 to 0.4 kcal/g—to the diet.

This distinctive metabolic behaviour results in minimal impact on blood glucose and insulin levels, making allulose an attractive ingredient for products targeting diabetic, ketogenic, and low-glycaemic consumer segments. Its compatibility with these dietary frameworks is well-supported by emerging clinical evidence.

Beyond its glycaemic neutrality, growing scientific research points to additional physiological benefits:

• Postprandial glucose suppression: Co-ingestion with carbohydrates has been shown to attenuate blood glucose spikes, potentially supporting glycaemic control in individuals with type 2 diabetes.
• Visceral fat reduction: Preclinical and early human studies indicate that regular consumption of allulose may help reduce abdominal fat accumulation.
• Antioxidant and hepatoprotective effects: Investigations in animal models suggest that allulose may offer protection against oxidative stress and support healthy liver function.
• Potential lipid-lowering activity: Some studies also suggest a role in modulating blood lipid levels, which could have cardiovascular implications.

Taken together, these findings position allulose not only as a functional sweetener but also as a bioactive compound with nutritional and therapeutic potential—a rare dual role in modern food science.

4.1. Regulatory Status

Allulose is “Generally recognized as safe” (GRAS) by the U.S. FDA and is exempt from "Sugars" labelling on the Nutrition Facts Panel in the U.S., although it must still be listed in the ingredient list. It's also approved in countries like Mexico, Japan, and Singapore, but not yet in the EU, where its regulatory journey continues.

• United States: Allulose is designated as GRAS (GRN 400) and exempt from total and added sugars labeling, though it must appear on the ingredient list.
• Japan & South Korea: Permitted and already in wide commercial use.
• Singapore & Mexico: Approved for use in food and beverages.
• European Union: Currently under scientific review; not yet approved for use as a novel food.

The ingredient's labeling exemption from sugar content in the U.S. offers a significant competitive edge, especially in thelow-sugar product positioning.

5.1. Formulation Considerations

Despite its benefits, formulators must consider a few limitations:

• Digestive tolerance: High doses (typically >15–20g per serving) may cause gastrointestinal discomfort in sensitive individuals.
• Cost: Allulose is more expensive than conventional sugars or polyols like erythritol.
• Synergistic use: Often paired with stevia, monk fruit, or fibres to achieve optimal sweetness and texture profiles.

6.1. Market Trends and Future Outlook

As consumer demand for low-sugar, clean-label and diabetes-friendly products grows, allulose is gaining rapid traction. Major brands have begun integrating it into protein bars, low-carb snacks, beverages, and keto desserts. The global allulose market is projected to expand significantly, fueled by increasing acceptance among both food manufacturers and health-focused consumers.

Ongoing R&D aims to improve:

• Fermentation-based and enzymatic production efficiencies
• Microbial strain development for yield optimization
• Combination systems with fiber matrices and polyols for enhanced satiety and prebiotic effects