Detailed Explanation of the Processing Technology of Charcoal-Grilled Octopus

Octopus belongs to the phylum Mollusca, class Cephalopoda, and has 8 arms; it is also known as "eight-clawed fish" or "qiao". There is Octopus vulgaris, commonly known as true octopus; Octopus ocellatus, commonly known as rock octopus; and long-arm octopus, commonly known as wangchao. Octopus inhabits the seabed, crawling or swimming with its arms, and feeds on benthic small fish, shrimp, crabs and shellfish. It is distributed along the coastal areas of China.

Octopus meat is thick and plump and is an excellent seafood product; it is not only rich in nutrients, delicious in taste and unique in texture, but also has high medical value. It is deeply welcomed by Chinese and foreign consumers and has always been sold as a high-grade aquatic product @#@136@#@. However, octopus has problems such as poor storability, high cost of keeping it alive, difficult processing and high market price, which to a certain extent have affected the development of octopus products and market sales. Foreign markets have always had a large demand for octopus products, and there are also many varieties, which are well worth learning from by domestic factories and sellers. The processing technology of charcoal-grilled octopus sold on the Japanese market is summarized below for everyone's reference.

I. Process Flow

Raw material -> evisceration -> cleaning 1 -> removal of sand and mucus from arms -> rinsing -> removal of mouth and beak -> cleaning 2 -> cutting -> sorting -> skewering -> steaming and boiling -> cooling and cleaning -> draining -> charcoal grilling -> cooling -> removal of steel needles -> re-sorting -> vacuum packaging -> freezing -> metal detection -> boxing -> finished product inspection -> frozen storage -> shipment

II. Key Operating Points

1. Raw material: use true octopus with a single specimen size of more than 1 kg, requiring a normal odor, no off-odor, a color that is the natural color of true octopus, and no reddening or other spoilage phenomena, with good freshness. Frozen raw materials should be thawed in a thawing tank with running water; the water temperature must not be higher than 10°C, and after thawing, ice should be added to keep it cool. Fresh raw materials should be processed as soon as possible after purchase.

2. Evisceration and removal of impurities: turn the octopus head over and remove the internal organs. Special attention should be paid to dangerous foreign matter such as shrimp spines and fish bones that may pierce through the internal organs into the octopus meat; do not damage the integrity of the octopus head. Then rinse the debris clean, and after cleaning add ice to keep it cool.

3. Treatment for removing sand and mucus from the arms: after cleaning, use salt, alum combined with mechanical water washing and other methods to thoroughly remove the sand and mucus from inside the octopus arms; repeat 2 to 3 times if necessary, and pay attention to controlling the water temperature.

4. Removal of mouth and beak: first cut off the nose, then make an incision from above the eyes, separate these two arms, dig out the hard beak inside, and separate the octopus head from the arms, while also cutting off the neck. Then carry out manual cleaning, using running water and brushing, mainly to wash away residual fine debris on the head skin and the suckers of the arms, and finally rinse with cleaning water.

5. Cutting: separate the cleaned true octopus head and arms, requiring the 8 arms to be separated one by one, and the head to be used for other purposes.

6. Sorting: weigh and sort each arm according to specification requirements. The specifications are generally divided into: 60 g-120 g, 120 g-200 g, and above 200 g, or handled according to special customer requirements.

7. Skewering and steaming/boiling: use stainless steel needles to skewer the octopus arms. When skewering, the octopus arms should be in a naturally contracted state, not too tight, so as to avoid contraction and breaking during steaming/boiling and charcoal grilling. Then steam/boil in hot water above 90°C; the steaming/boiling time differs slightly for different specifications. After steaming/boiling, immediately cool with ice water, clean the surface of the octopus arms, and then drain.

8. Charcoal grilling: grill over charcoal fire on special charcoal grilling equipment to make the octopus arms light yellow. The time and heat are controlled by experience and differ slightly according to size specification. After charcoal grilling, the color of the octopus arms is required to be basically consistent, with no obvious differences. After charcoal grilling, enter a cooling room and rapidly cool to below 10°C. Then remove the stainless steel needles, trying as much as possible to keep the octopus arms in the straight shape they had when skewered, and pay attention to hygiene during operation.

9. Sorting and packaging: carry out re-sorting according to specification requirements, dividing into three specifications of 7-10 pieces, 4-6 pieces, and 2-3 pieces per 500 g, or according to special customer requirements. Vacuum-pack according to each specification, requiring neat, flat placement, no overlapping, and good sealing strength. The packaged products enter a quick-freezing room for freezing, so that the center temperature of the product reaches below -18°C.

10. Metal detection: set the precision of the metal detector to Feφ1.0 mm, SUS2.5 mm, and pass the products through the metal detector one layer at a time, one by one; there must be no overlapping, otherwise detection may be incomplete and hidden quality risks may remain. When the metal detector is started, before it is shut down, and during operation every 30 minutes, use standard test blocks to test its sensitivity, so as to confirm that the metal detector is always in normal working condition.

11. Boxing: mark the products with the production date or final taste date, and pack the products into corresponding outer packaging boxes according to different specifications and packaging.

12. Finished product inspection: before entering storage, sample inspection should be carried out to check whether the weight, specification and batch number of each box and each bag of finished product conform, and whether the color and flavor are normal. In addition, the sealing and vacuum conditions are required to be checked, and microbiological and other indicators should be tested.

13. Frozen storage: store the products in a cold storage with a warehouse temperature below -20°C to keep the center temperature of the products controlled below -18°C. They are required to be stacked separately according to production date and specification to facilitate entry and exit.

14. Shipment: all refrigerated containers or transport vehicles carrying products should be pre-cooled to -7°C to 0°C before loading, and cooled to below -20°C during transport, so that the center temperature of the products is controlled below -18°C during transport, ensuring product quality.

III. Quality Indicators

1. Sensory indicators:

The finished product should have the natural charcoal-grilled color of octopus, light yellow, basically consistent in color, with a glossy appearance; the arms should be complete in shape, basically consistent in size within the same specification, relatively crisp in texture, and good in toughness; the odor and taste should be good, with no undesirable off-odor and no foreign impurities.

2. Hygiene indicators

The total bacterial count must be lower than <=3×104 cfu/g; coliform bacteria must not be higher than 30 MPN/100 g; Escherichia coli and pathogenic bacteria (Salmonella, Staphylococcus aureus, Vibrio parahaemolyticus) must not be detected; volatile basic nitrogen lower than 30 mg/kg; inorganic arsenic (calculated as As) lower than 0.5 mg/kg; mercury (calculated as Hg) lower than 0.3 mg/kg.

3. Shelf life

When the product is stored frozen at -18°C, the shelf life can reach 12 months.