Processing of quick-frozen large silverfish

Quick-frozen silverfish are exported to Japan, Southeast Asia and Europe, especially popular with Japanese consumers. With the continuous improvement of the output of large silverfish in the reservoir, quick-frozen big silverfish has become one of the export aquatic commodities with high exchange rate in China.

1. Preservation and transportation of raw fish

The big silverfish has a small body and thin skin, is prone to corruption and deterioration, and has strong seasonality in production. In order to ensure the quality of silverfish, when fishing, you can disembark with ice and keep it fresh at the first time. The specific method is to first select and classify the large silverfish caught on the ship, wash them, and slightly freeze them to keep the central temperature of the fish at about-3 ℃. Then, put the layer of ice in the heat preservation fish box, which should be done:

① with catch ice, ice layer ice, ice clean, small ice shape, the amount of ice depending on the climate, transportation distance and time, the proportion of ice fish 1:1-2:1.

② uses a larger plastic heat preservation fish box, each containing fish 10kg-15kg, covered and sealed, with a leakage hole in the bottom of the box to prevent the fish from being whitened by the accumulation of melting ice.

③ is connected to surface transportation to achieve fast loading, express transportation and quick unloading, and the requirements from production to processing plant do not exceed 10h-20h.

2. Processing process

Raw material treatment → cleaning → leachate → weighing → bagging → packing → Quick Frozen → Cold Storage

3. Operation essentials

(1) Raw material acceptance: raw material fish requires good freshness and fatness, complete strip shape, natural color, clear eyes, elastic muscle, no dirt and mucus, clear smell and no peculiar smell of cucumber. Upon arrival, the raw fish is immediately unloaded to the processing workshop, box-by-box inspection and removal of defective products, pay attention to bare-handed grasp operation, do not use nail rakes, shovels and other hard tools, so as not to destroy the integrity of the fish.

(2) cleaning: use fish washing machine or manual rinsing, add large silverfish to evenly, avoid fish layer is too thick, affect rinsing quality. Clean with deep well water or tap water after cooling with ice, wash it several times and pick it up. Cleaning should be rapid, the front and back processes should be closely coordinated, and there should be no backlog.

(3) picking and draining water: while rinsing, remove the ice and weeds floating on the surface of the water, and pick out other fish and shrimp. Put the rinsed silverfish into a container with a leak at the bottom and drain 10min-20min.

(4) weighing: large silverfish that have been leached are weighed and bagged according to different specifications. When weighing, the net weight of each bag of silverfish must be 500g or 1000g after thawing, so it should be weighed by 10% depending on the size of the fish and the degree of filtration. Then put the silverfish bag into a carton, put it in a special frozen silver fish plate, each with 10 boxes, and send it to the quick-frozen warehouse in time.

(5) Quick freezing: the silverfish plates are arranged neatly on the pipe rack of the quick freezer. The temperature of quick-frozen storage should drop rapidly to below-25 ℃. After 15h-16h, the freezing process is completed when the central temperature of the fish reaches-15 ℃.

(6) packing and cold storage: immediately out of the warehouse after quick freezing, packed at low temperature, 20 boxes per box, net weight 10kg or 20kg. The bottom of the carton and the top cushion corrugated paper, the external bandage is firmly tied, and the product name, specification, weight, factory date, etc., are immediately sent to the freezer for storage. The cold storage temperature should be kept at-18 ±2 ℃, stacked according to production batches, specifications, and stored for no more than 12 months. When leaving the factory, the frozen silverfish center temperature does not exceed-15 ℃. When transporting and exporting, it must be transported by refrigerated truck at low temperature.

4. Quality of finished products

Require smooth frozen block, uniform ice coat, clean, air-free dry oxidation and ice blackening caused by slow freezing; silverfish fresh, complete and clear, with translucent shape, no belly breaking or abdominal expansion, no dirty mucus, solid muscle tissue, good elasticity; no peculiar smell; basically no yellow stripes; general body length 18cm-22cm, no lower than the prescribed weight after thawing.