In the seafood processing industry exporting to the most demanding markets such as Japan, the United States, and the European Union (EU), value-added shrimp products include: Nobashi shrimp (straight-striped shrimp specifically for tempura frying), PTO shrimp (Peeled Tail On – peeled shrimp with tails left on) and HOSO shrimp (whole shrimp with head) It always demands strict standards regarding physical appearance, mechanical properties, and microbiology.
Exported Nobashi shrimp and PTO shrimp retain their natural straight shape and intact pink tail tips.
A standard freezing line goes beyond simply lowering the core temperature of the product; it must also ensure that the shrimp maintain their straight shape, protect the tail tips from breaking or bruising, and lock in moisture with a smooth, uniform glazing. Tan Long Refrigeration and Electrical Engineering Joint Stock Company We offer a complete, integrated solution: from pre-cooling with flake ice machines, ultra-fast IQF mesh freezing, automatic spray glazing machines to REF refreezing conveyor belts.
1. Strict Export Standards for Nobashi Shrimp & PTO Shrimp
When processing high-value shrimp for export, factories face three main technological challenges:
- Protecting the caudal morphological features: Exported Nobashi shrimp and PTO shrimp rely heavily on the sensory value of intact, pinkish-red tail tips. Primitive freezing conveyors often cause shrimp tails to stick to the mesh, resulting in a tail breakage rate of 5–81 TP3T during separation.
- Dehydration and Freezer Burn: After molting, shrimp lose their natural protective layer. If frozen for an extended period, the surface of the shrimp meat will become porous, dry, and the protein will denature.
- Uniformity of the ice glaze layer: The glazing ratio in export contracts ranges from 5% to 20%. The glazing film must thinly and evenly cover the entire shrimp, without clumping or creating microbial gaps.
2. The 4-Step Closed-Loop Technology Diagram of Tan Long's Production Line
Tan Long designed a continuous, one-way flow of equipment to prevent cross-contamination and ensure absolute food safety and hygiene:
Step 1: Keep Shrimp Fresh Using a Stone Crusher (0°C to 2°C)
Throughout the process of preparing, removing the heart, slitting the belly vein, and straightening Nobashi shrimp, the raw shrimp are continuously kept chilled using flake ice produced from... Tan Long stone mill. Flake ice has outstanding advantages: the dry ice sheets are thin, 1.5 – 2.2mm thick, with a smooth surface and no sharp edges, allowing for a wide heat contact area without crushing the shrimp meat or tearing the muscle tissue.
Tan Long stainless steel flake ice machine produces thin, dry flake ice from -7°C to -9°C, optimally preserving the freshness of raw shrimp.
Step 2: Ultra-Fast Freezing Using IQF Mesh Conveyor Belt (-40°C)
The shrimp, after being shaped, are directly added. mesh belt IQF freezer Tan Long (flexible design capacity range from 500, 750 to 1,000 kg/h):
- The conveyor belt is made of food-grade 304 stainless steel, with a high-density weave to prevent shrimp tails from getting caught.
- The two-way forced-air system creates a high-speed circulating cold air flow, lowering the core temperature of the shrimp from +10°C. -18°C in just 8-15 minutes.
- The gentle mechanical vibration mechanism separates each shrimp individually, completely preventing them from sticking together.
The Tan Long IQF ultra-fast mesh conveyor belt helps shrimp achieve perfect freezing without deformation.
Step 3: Automatic Cold Water Glazing
Upon exiting the IQF freezing chamber, the shrimp immediately pass through. automatic spray coating machine. The ice glaze is cooled to 0.5°C – 1.5°C and sprayed in a low-pressure cone to coat the shrimp. A system of control valves and conveyor belt speed allows for precise control of the ice glaze ratio from 5% to 15% according to each export order.
Step 4: Instantly Freeze the Water Film with the REF Refreezing Conveyor Belt
After being sprayed with ice-glazing water, to prevent the outermost layer of water from melting the surface or sticking together during packaging, the shrimp pass through... the REF re-freezing belt (Hardening Freezer). In a refreezing chamber at -35°C for approximately 1.5–3 minutes, the ice film is instantly frozen solid, creating a transparent "ice armor" that protects the shrimp from lipid oxidation during 12–24 months of international storage and transport.
3. Equipment Configuration Table for a Shrimp Processing Plant with a Capacity of 5–10 Tons/Day
| Equipment Category | Technical Specifications & Configurations | Achieved Standard |
|---|---|---|
| Tan Long stone mill | Capacity 5-20 tons/24h, SUS 304 stainless steel die, shaping cutting blades. | Thin, dry ice, ice output temperature -7°C to -9°C |
| Mesh belt IQF freezer | 500 – 1,000 kg/h, variable frequency drive for time adjustment 5 – 30 minutes, 150mm PU panel walls. | Shrimp core temperature -18°C, weight loss less than 0.8% |
| Automatic glazing machine | Stainless steel anti-clogging spray nozzles, circulating pump for cooling ice-coated water. | Uniform glazing ratio with a tolerance of ±1% |
| REF refreezing conveyor | Operating time: 1.5 – 4 minutes. Stainless steel indoor unit with aluminum fins and widely spaced fins to prevent frost buildup. | The ice film is shiny and non-stick to the packaging. |
Tan Long B2B Technical Consulting
Get your Cold Chain Capacity Calculation & Estimate within 24 Hours
Tan Long's engineering team conducts on-site surveys, calculates cooling load, and advises on equipment configurations to optimize operating electricity costs and meet stringent export standards (HACCP, FDA, GACC China).
✓ 10,000m² factory in Duc Hoa 1
✓ Partners: Bitzer, Mayekawa
