Preguntas frecuentes

What are the differences between High-Acyl (HA) Gellan Gum produced via High-Temperature Extraction vs. Room-Temperature Extraction?

The extraction method of HA Gellan Gum significantly alters its molecular conformation, hydration behavior, and final gel properties. Currently, the industry employs two primary methods: High-Temperature Short-Time (HTST) extraction and Room-Temperature Solvent extraction.

1. High-Temperature Extraction (e.g., Plate Heat Exchanger Method)
In this process, the fermentation broth is rapidly heated using a plate heat exchanger, held briefly, and immediately precipitated with lower alcohols (ethanol or isopropanol).

Key Advantage (Process): It effectively kills the production strain, protecting the fermentation environment from contamination. It also inactivates indigenous enzymes, improving product stability.
Unique Hydration Behavior (Swelling): HA Gellan produced this way exhibits a characteristic "Rapid Swell." Upon addition to water, the viscosity spikes immediately as the powder hydrates. The viscosity remains high until the solution is heated to 70–80°C, at which point it drops sharply.
Scientific Reason: High temperatures during extraction cause the double-helix structures to "open" or relax. Consequently, the finished powder has superior water affinity, leading to instant hydration and high initial viscosity.

2. Room-Temperature Extraction
This method involves mixing the fermentation broth directly with alcohol at ambient temperature under high-speed agitation to precipitate the gum.
Key Advantage (Texture): It yields a product with higher Elastic Modulus (G') and Gel Strength. Because the molecular structure is never subjected to thermal stress during recovery, the native polymer chains remain more intact and robust.
Slow Hydration: Unlike the high-temperature version, this type shows a gradual, slow increase in viscosity during dispersion, as the tightly wound native helices take longer to hydrate.

Color & Purity: The color tends to be darker. Alcohol is less efficient at stripping pigments and impurities at room temperature compared to the higher kinetic energy of a heated system.

Summary Comparison Table