Engineered single-chain monellin derivatives as high-intensity, low-calorie sweeteners for beverages

Overview

Natural sweet proteins represent an underexploited class of high-intensity, low-calorie sweeteners. Among them, monellin stands out for its clean taste, very high sweetness potency, and small size, which makes it amenable to scalable and sustainable production. Researchers at Università degli Studi di Napoli Federico II have engineered a new generation of single-chain monellin derivatives built entirely from natural amino acids. These variants deliver significantly higher sweetness than the native plant protein while overcoming its main limitation: poor thermal stability. The result is a sweetener platform suitable for demanding beverage applications, including carbonated soft drinks, where sugar reduction is a major industry priority.

Technical specifications

Key features and demonstrated capabilities:

• Multiple single-chain monellin derivatives designed, produced, and characterized at lab scale, with published evidence of increased sweetness and stability
• Greater than six-month shelf life demonstrated for two selected variants at acidic pH 2.5 and neutral pH 6.8, at both 4 °C and 37 °C
• Equisweetness and temporal sweetness profile characterized by trained sensory panels against commercial sweeteners
• Pilot production of two variants in tobacco leaves as a scalable bio-manufacturing route
• Preliminary metabolic studies in rodent high-fat diet models and ecotoxicity assessment showing no genotoxicity and no acute environmental toxicity
• Composition limited to natural amino acids, with full degradation by endogenous proteases, supporting a streamlined regulatory pathway

Next-stage optimization areas:

• High-throughput screening and simplified gustatory assays to select the best candidate
• Taste profile optimization through blending with other protein and non-protein sweeteners
• Evaluation of industrial processing effects on stability and taste
• Scale-up in GRAS-certified production systems
• Shelf-life and packaging studies
• Comprehensive toxicity testing for human regulatory approval

Technology readiness level

The technology is currently at an advanced laboratory-to-pilot stage. Multiple monellin variants have been designed, produced, and characterized, with peer-reviewed publications documenting sweetness, stability, shelf life, sensory performance, scalable expression, and preliminary safety. Remaining work focuses on taste optimization, industrial-scale GRAS production, packaging validation, and formal toxicology to enable commercial deployment in beverages and other food applications.