IQF Frozen Spring Onion

1. Raw Material Harvesting

Select fresh, green onions free of yellow leaves, pests, and diseases.

Harvest when onions are moist with dew for optimal water content, nutrition, and crispness.

2. Washing Process

Remove dirt, withered leaves, and yellowed parts, keeping the onion white and petiole intact.

Rinse repeatedly with running water to remove dust and impurities.

Use slightly alkaline electrolyzed water to eliminate bacteria and pesticide residues, followed by a clean water rinse.

3. Slicing

Slice onions evenly to 3-5 cm lengths for consistent processing.

Ensures balanced heating and cooling during refrigeration and thawing, maintaining quality.

4. Blanching & Color Protection

Blanch in 90-95°C water for 30-60 seconds to inhibit oxidase and prevent browning.

Add citric acid and ascorbic acid to preserve bright green color.

Immediately cool in cold water to maintain quality.

5. Quick Freezing

Drain excess water using a centrifuge or resonance screen to minimize ice crystal formation.

Use a fluidized bed quick freezer to rapidly reduce the internal temperature to below -18°C, ensuring small, uniform ice crystals and intact tissue structure.

6. Packaging & Storage

Use suction or inert gas (e.g., nitrogen) packaging in waterproof, airtight multi-layer plastic film bags.

Store in -18°C cold storage with regular inspections to prevent temperature fluctuations.

Shelf life: 12-24 months with consistent quality.