SWEET-GRASP: Sustainable extraction of acid- and heat-stable sweet proteins from GRAS microalgae for beverage applications

Overview

SWEET-GRASP addresses a key limitation of existing sweet proteins: their instability under acidic conditions and high temperatures, which has restricted their use in beverages. The project screens extremophile microalgae classified as Generally Recognized as Safe (GRAS) to identify strains that naturally produce sweet proteins capable of withstanding the harsh processing conditions of beverage manufacturing. By sourcing these proteins from microalgae, the initiative offers a sustainable, plant-based alternative to artificial sweeteners and conventional sugars, aligning with consumer demand for healthier and environmentally responsible products.

The value proposition centers on three pillars: clean-tasting sweetness from natural proteins, regulatory safety through GRAS status, and sustainability through microalgae-based production. Successful identification and extraction of these proteins would provide beverage manufacturers with a novel sweetening ingredient that supports health-conscious branding and sustainability goals.

Technical specifications

Research approach:

• Screening and selection of extremophile GRAS microalgae strains that thrive in acidic environments and at elevated temperatures
• Optimization of cultivation parameters including pH, temperature, light intensity, and nutrient composition to maximize sweet protein yield
• Development of an efficient extraction protocol to isolate sweet proteins from microalgae biomass
• Acid and heat stability screening using spectroscopic and biochemical analyses to evaluate protein performance under simulated beverage processing conditions
• Sensory evaluation in collaboration with sensory experts to characterize sweetness intensity, taste profile, and optimal concentration compared to traditional sweeteners

Key characteristics sought:

• High sweetness potency with a clean taste profile
• Stability under acidic conditions (relevant to beverage formulations)
• Stability at high temperatures (relevant to pasteurization and processing)
• GRAS classification ensuring safety for human consumption
• Sustainable sourcing through microalgae cultivation

Technology readiness level

The project is at an early research stage. Previous studies have identified sweet proteins with high sweetness and clean taste, but their instability under acidic and high-temperature conditions has hindered beverage application. The SWEET-GRASP approach builds on these findings by targeting extremophile microalgae capable of producing functional proteins under extreme conditions, as demonstrated by prior identification of microalgae thriving at pH levels as low as 2.0 and temperatures up to 50°C.

The planned validation pathway includes five sequential phases: microalgae selection, growth condition optimization, protein extraction, acid and heat stability screening, and sensory evaluation. Each phase will generate data to confirm whether the identified proteins meet the functional and sensory requirements for beverage applications. The current readiness level is best described as early-stage discovery and feasibility research, with further development required before commercial application.