Invertase Enzyme in Food Processing
Introduction
Invertase, also known as β-fructofuranosidase, is an enzyme widely used in the food industry. It catalyzes the hydrolysis of sucrose into glucose and fructose, forming invert sugar. This process enhances sweetness, improves texture, and stabilizes food products. This document explores the definition, sources, types, production process, applications, advantages, and technical parameters of invertase.
Definition of Invertase
Invertase is an enzyme that breaks down sucrose into glucose and fructose. This reaction is significant in food processing, particularly in confectionery, baked goods, and beverages, where invert sugar improves solubility, moisture retention, and sweetness.
Sources of Invertase
Invertase can be obtained from various natural sources:
1. Microbial Sources:
- Yeast: Saccharomyces cerevisiae
- Bacteria: Zymomonas mobilis, Bacillus subtilis
- Fungi: Aspergillus niger, Penicillium species
2. Plant Sources:
- Present in sugarcane, sugar beets, and other sucrose-containing plants.
3. Animal Sources:
- Found in the digestive systems of some animals.
Recombinant Technology:
- Genetically engineered microorganisms are used to enhance invertase yield, stability, and purity for industrial applications.
Types of Invertase
Invertase exists in two main forms:
- Soluble Invertase: Found in the cytoplasm and used in liquid-based applications.
- Insoluble Invertase: Associated with cell walls and used in immobilized enzyme systems for continuous processing.
Production and Isolation Process
The production of invertase involves microbial fermentation followed by purification.
Process Steps:
- Inoculation: Cultivation of Saccharomyces cerevisiae or other microbes in a nutrient-rich medium.
- Fermentation: Optimized pH (4.5-5.5) and temperature (30°C-35°C) conditions for enzyme production.
- Harvesting: Centrifugation to separate microbial cells from the fermentation broth.
- Purification:
- Precipitation using ammonium sulfate.
- Dialysis for impurity removal.
- Chromatographic techniques (ion-exchange or gel filtration) for high-purity enzyme.
- Concentration: The final enzyme is concentrated for storage and application.
Flow Diagram:
Microbial Culture → Fermentation → Centrifugation → Precipitation → Dialysis → Chromatography → Concentration → Purified Invertase
Applications in Food Processing
Invertase is utilized in various food industries:
- Baking:
- Prevents sugar crystallization in icings and fillings.
- Enhances dough fermentation by breaking down sucrose.
- Brewing:
- Converts sucrose into fermentable sugars, enhancing fermentation.
- Contributes to flavor development in alcoholic beverages.
- Dairy:
- Used in the production of sweetened condensed milk and flavored yogurts.
- Prevents sucrose crystallization in dairy-based desserts.
Advantages and Disadvantages of Invertase
Advantages:
- Improves sweetness and solubility.
- Enhances moisture retention in food products.
- Prevents crystallization, ensuring smooth textures.
- Broad applicability in diverse food sectors.
Disadvantages:
- Sensitive to temperature and pH fluctuations.
- High production and purification costs.
- Potential allergenicity in sensitive individuals.
- Requires controlled storage to maintain enzymatic activity.
Technical and Quality Parameters
| Parameter | Specification |
| Optimal pH Range | 4.0 to 5.5 |
| Optimal Temperature | 50°C to 60°C |
| Enzyme Activity | 300 to 500 U/mg (varies by source) |
| Stability | Retains activity under cold storage |
| Assay Method | DNS (3,5-dinitrosalicylic acid) assay for reducing sugars |
Physical and Chemical Properties of Invertase
| Property | Value/Range |
| Molecular Weight | 100,000 to 135,000 Daltons |
| Solubility | Soluble in water |
| Enzyme Class | Hydrolase |
| Isoelectric Point (pI) | 4.0 to 4.6 |
Conclusion
Invertase is a valuable enzyme in food processing, offering multiple benefits such as improved sweetness, enhanced moisture retention, and prevention of crystallization. Its wide range of applications in baking, brewing, and dairy industries highlights its importance. Understanding its properties and optimal usage ensures better product quality and processing efficiency.