Processing technology of large silverfish (1)

Large silverfish, also known as noodle fish, was widely distributed in the middle and lower reaches of the Yangtze River and affiliated lakes. Its meat is delicious and nutritious, and it has a special fragrance of cucumber. The large silverfish is generally about 20 cm long and has no bones and no thorns. It is a kind of small and valuable fish with high economic value and is very popular in domestic and foreign markets. This paper introduces the processing methods of two kinds of large silverfish.

1. Processing of quick-frozen large silverfish

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, slightly freeze them, keep the central temperature of the fish body at about 3 ℃, and then put the fish layer of ice in the heat preservation fish box, which should be done:

① with catch ice, ice layer ice, ice clean, ice shape is small, ice consumption depends on climate, transportation distance and time, ice fish ratio of 1 ∶ 1 to 2 ∶ 1.

② uses a larger plastic heat preservation fish box, each containing 10 kilograms of fish, sealed with a lid, and a leak in the bottom of the box to prevent the fish from being whitened by ice-melting water storage.

③ connects with surface transportation to achieve fast loading, express transportation and quick unloading. It takes no more than 10 to 20 hours from production to processing plant.

two。 Processing process flow

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

3. Key points of operation

(1) Raw material acceptance: raw fish requires good freshness and fatness, complete strip shape, natural color, clear eyes, elastic muscle, no dirt and mucus, clear fragrance and no peculiar smell. 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. Place the rinsed silverfish in a container with a leak at the bottom and drain for 10 to 20 minutes.

(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 guaranteed to be 500g or 1000 g after thawing and filtering water, 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 15-16 hours, the freezing process is completed when the central temperature of the fish reaches-15 ℃.

(6) packing and cold storage: out of the warehouse immediately after quick freezing, packed at low temperature, 20 boxes each with a net weight of 10 kg or 20 kg. 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 temperature of cold storage should be kept at-18 ℃ ±2 ℃, stacked according to production batches and 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. Finished product quality

Require smooth frozen blocks, uniform ice clothes, clean, air-free dry oxidation and ice blackening caused by slow freezing; silverfish are 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; the general body length is 18cm to 22cm, not less than the prescribed weight after thawing.