🔬 SECTION 12: QUALITY CONTROL AND TESTING METHODS FOR GELLAN GUM
Ensuring Consistency, Purity, and Performance
Maintaining high-quality gellan gum is critical for reliable application and customer satisfaction. This section outlines key quality parameters, testing methodologies, and best practices for manufacturers, suppliers, and users.
📌 1. KEY QUALITY PARAMETERS
| Parameter | Importance | Typical Specification |
|---|---|---|
| Appearance | Visual check for purity and consistency | Fine, free-flowing off-white powder |
| Moisture Content | Affects shelf life and powder flow | ≤ 15% |
| Ash Content | Indicates mineral residue | ≤ 15% |
| pH (0.5% aqueous solution) | Impacts solubility and gelation | 5.0 – 7.0 |
| Gel Strength | Determines gel firmness and texture | 300 – 1300 g/cm² (depending on type) |
| Viscosity (solution) | Reflects molecular weight and hydration | Varies by grade, typically 6000 – 8000 mPa·s at 0.5% |
| Calcium Content | Essential for ion-induced gelation | Controlled per product grade |
| Microbial Limits | Ensures safety and hygiene | Total plate count < 10000 cfu/g; absence of pathogens (E. coli, Salmonella) |
| Heavy Metals | Safety compliance | Below regulatory limits (e.g., Pb < 10 ppm) |
🔬 2. TESTING METHODS
a) Appearance and Physical Properties
- Visual inspection for color and uniformity.
- Particle size distribution by sieve analysis or laser diffraction.
- Moisture content by Karl Fischer titration or gravimetric methods.
b) Chemical Analysis
- Ash content via muffle furnace incineration.
- pH measurement in 1% aqueous dispersion using calibrated pH meter.
- Calcium and other ions by atomic absorption spectroscopy (AAS) or inductively coupled plasma (ICP).
c) Functional Testing
- Gel strength measured by texture analyzer or rheometer using standard protocols (e.g., gel formed with specified concentration and calcium).
- Viscosity measured by viscometer (Brookfield or rotational rheometer) at controlled temperature and concentration.
d) Microbiological Testing
- Total aerobic microbial count using plate count methods.
- Pathogen detection via selective culture or PCR methods.
e) Heavy Metal Analysis
- Inductively Coupled Plasma Mass Spectrometry (ICP-MS) or Atomic Absorption Spectroscopy (AAS).
⚙️ 3. BEST PRACTICES FOR QUALITY ASSURANCE
- Raw Material Inspection: Verify supplier certificates of analysis and perform batch testing.
- Standardized Sampling: Follow ISO or USP guidelines for representative sampling.
- Documentation: Maintain detailed records of testing results and production batches for traceability.
- Storage: Store gellan gum powder in a cool, dry place in airtight containers to prevent moisture absorption and contamination.
- Process Control: Monitor critical parameters like temperature, pH, and mixing speed during hydration and formulation.
- Continuous Improvement: Implement corrective actions based on quality deviations and customer feedback.
