Processing Methods and Technical Points for Mantis Shrimp

Mantis shrimp is also called shrimp crawling child, scientific name Oratosquilla oratoria. The body is flat, the pleopods and tail fan are well developed, the carapace on the front part of the body is very thin, and the rear part is thicker, the rostrum is not prominent, the carapace is wide and round, the first pair of thoracic legs is pincer-like, asymmetrical, with sexual dimorphism, and there are two protrusions on the inner margin.

Mantis shrimp is the main bycatch of fixed nets in the Bohai Sea, with the spring fishing season from April to July and the autumn fishing season from October to November. It can be processed into frozen boiled mantis shrimp with shell and frozen boiled headless mantis shrimp.

I. Processing of frozen boiled mantis shrimp with head

1. Quality conditions: fresh quality, plump shrimp meat, with roe, normal color, no off-odor.

2. Process flow: raw materials - rinsing - sorting - boiling - cooling - grading - boxing - quick freezing - packaging - cold storage

① Sorting: rinse the raw shrimp clean, and according to quality standards select female shrimp with plump meat, in a fresh and live state, and with roe for processing.

② Boiling: put the selected female mantis shrimp into boiling water containing 3% salt, with a shrimp-to-water ratio of 1:50, bring the water to a boil within one minute, keep it boiling for 2 minutes, then remove the shrimp. During boiling, the heat must be high; the shrimp must be cooked through, but not cooked slowly over a long time so that the meat becomes tough. The salt water must be changed once after each batch, and completely replaced after every 5 batches.

③ Cooling: natural cooling

④ Grading: according to the length of each specimen (from the base of the eyestalk to the tip of the tail), divide into six specifications: 9-10 cm, 11-12 cm, 12-13 cm, 13-14 cm, 14-15 cm, and above 15 cm. After grading, place the shrimp bodies separately into clean trays, and put in one specification label.

⑤ Boxing: neatly put the shrimp bodies into transparent plastic bags, with an equal number of shrimp bodies in each bag, and place them flat into small cardboard boxes, fold the bag opening well, and close the box lid.

⑥ Quick freezing: send the boxed shrimp into a -25°C freezing room and freeze for 3 hours.

⑦ Packaging: use corrugated cardboard boxes lined with polyethylene plastic bags; the fixed quantity per box depends on customer requirements; brush the product name, specification, weight, etc. on the outside of the box, bundle with plastic bags on the outside, and store in a constant-temperature warehouse at -20°C.

II. Processing of frozen boiled headless mantis shrimp

1. Process flow: raw materials - rinsing - boiling - cooling - head removal - quick freezing - tray removal - packaging - cold storage.

2. Operational requirements

① Raw material selection: separate live mantis shrimp into female and male bodies, and remove substandard products; shrimp that have spawned must not be processed.

② Boiling: put female and male bodies separately into 3-4% salt boiling water for boiling; boil female bodies for 5 minutes and male bodies for 4 minutes; other requirements are the same as for boiling mantis shrimp with head.

③ Cooling: immediately put the boiled mantis shrimp into clean drinking water for rapid cooling.

④ Head removal: use sharp stainless steel scissors to cut off the head at the junction between the shrimp head and the neck segment; female and male bodies must be stacked separately and must not be mixed.

⑤ Tray arrangement and quick freezing: when arranging on trays, place plastic paper at the bottom of the tray, on top, and between layers of shrimp to separate the shrimp bodies and prevent them from freezing together. Freeze for 3 hours in a warehouse at -25°C or below. Bring the temperature of the shrimp bodies down to -15°C.

⑥ Tray removal: pick it up and give it a gentle shake, and the shrimp will separate.

⑦ Packaging and cold storage: use hard cardboard boxes lined with polyethylene plastic bags, box the mantis shrimp bodies separately, line the top and bottom of each box with one sheet of corrugated paper each, and store in a constant-temperature warehouse at -20°C or below.