JPS5953803B2 - Method for preventing blackening of squid in boiled canned squid - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for preventing blackening in boiled canned squid, and more specifically, during the heat sterilization process in the production of boiled canned squid, hemocyanin-based blood containing copper ions and squid protein are decomposed from squid protein. The present invention relates to a method for producing boiled squid that can effectively prevent black or gray discoloration caused by reaction with generated hydrogen sulfide and has a high commercial value.

Squid, like other seafood, is generally fresh and large in size and eaten raw (such as sashimi), prepared dishes, or as raw materials for high-grade processing. Smaller ones are used for general processing.

Among these, raw squid for canning is generally used for processing, but a large amount of hydrogen sulfide is generated during heat sterilization during canned production.

In addition, many of the squid raw materials for membrane processing are frozen squids that are thawed, potted (removed internal organs), and then refrozen, and a large amount of hydrogen sulfide is released during the heat treatment of this refrozen squid raw material. Occur.

However, if a large amount of hydrogen sulfide is generated during heat sterilization, the meaty part of the squid will turn black or gray, and the product value will be lost when boiled. Hardly sold.

Therefore, when considering the cause of the black discoloration, it seems to be as follows.

This discoloration is thought to be caused by the reaction between copper ions present in the squid's hemocyanin blood and hydrogen sulfide decomposed from proteins during heat sterilization to produce copper sulfide, which appears black or gray. It will be done.

Therefore, in order to prevent this discoloration, it is effective to remove as much copper ion from the squid's blood as possible in advance, and to generate as little hydrogen sulfide as possible during heat sterilization.

The present invention was established based on the above knowledge, and specifically, uncooked squid is immersed in an alkaline solution containing phosphate, etc. to swell the flesh, and then soaked in running water. The blood, especially the copper ions contained in it, are removed and the remaining copper ions in the blood are fixed as metal complex salts.Then, the squid is heated in an acidic solution to make the squid meat acidic, and then it is further heated in an acidic aqueous solution when stuffing the meat. We propose a method for preventing black discoloration, which is characterized by suppressing the amount of hydrogen sulfide generated during heat sterilization treatment and preventing black or gray discoloration by injecting hydrogen sulfide.

The method of the present invention will be explained in detail below.

First, before manufacturing canned squid boiled in water, the inedible parts (cartilage, internal organs, etc.) of the squid are removed in an unheated state, i.e. in the raw state if it is raw, or after thawing if it is frozen. The squid is washed with water, and the pH of the squid is 7.5-9, which contains phosphates, etc.
．． The fleshy part is swollen by immersing it in the alkaline solution of step 5.

When this pre-swelling treatment is performed, the blood flows out from the fleshy part and the copper ions contained therein are removed, and the remaining copper ions in the blood form a metal complex salt with the phosphate in the solution. Fixed.

That is, in an alkaline solution, the fleshy part swells and blood flows out from the blood vessels.

However, even though most of the blood has drained out, some blood still remains in the fleshy parts, and during the heat sterilization process, this reacts with hydrogen sulfide produced by decomposition of proteins, producing black or gray sulfide.

In this regard, when phosphate is included in the solution, the reaction activity of copper ions is suppressed, and even if hydrogen sulfide is generated during the heat sterilization process, black or gray sulfide is not produced.

At this time, the alkaline solution has a pH of 7.5 due to the phosphate.
It is sufficient if the concentration of the phosphate is adjusted to about 9.5%, but the concentration of the phosphate is 0.05% to 3.0% by weight (hereinafter, % by weight is expressed as %), preferably 0.1% to 1.0%. It is preferable to add

Furthermore, during the swelling process, any proportion may be used as long as the blood in the fleshy part can swell in the alkaline solution to the extent that it can flow out by washing with water, but usually the alkaline solution is used in an amount of 1 to 3 parts by weight per 1 part by weight of the squid meat. , the temperature of the solution is 0 to 1
Preferably, the temperature is 0°C and the immersion time is 8 to 36 hours.

In addition, after the swelling treatment as described above, the soaking liquid and blood can be removed by transferring the squid to a water tank and exposing it to running water for 30 minutes, but it is not necessary to drain it by any means other than exposing it to water.

Next, after the blood has drained out, the squid is heated in an acidic solution so that the pEA' of the fleshy part is 5.4 or higher and as low as possible.

This acidic solution is usually adjusted to pH 2.0-4 by adding phosphate.
．． Adjust the temperature to about 0 and boil for 2 to 8 minutes at a temperature of 97°C. After boiling, cool the squid with water.

That is, the temperature of unheated squid meat is about 6.8 to 7.1, and in this state, a large amount of hydrogen sulfide is generated during heat sterilization.

Therefore, it is preferable to adjust the content of the fleshy part to be as low as possible during heat sterilization.

In this regard, considering the buffer action of proteins,
By boiling in an acidic solution, the quality of squid meat can be effectively adjusted to a low level of acidity in a short period of time, the amount of hydrogen sulfide generated during heat sterilization can be reduced, and discoloration such as black or gray can be prevented.

The reason why the lower limit of squid meat is set to 5.4 or less is because if it is lower than that, the meat becomes hard and brittle and loses its value as a food.

Table 1 shows an example of the relationship between the solution state during boiling in an acidic solution, the boiling time, and the state of the char meat after boiling.

In Table 1, the boiling temperature is 97℃, and the boiling solution is squid meat 1
This was done using 8 parts by weight, and the amount of squid meat before boiling was 60.

Next, after boiling and cooling the squid meat, remove the skin etc. if necessary, and then pack the meat into canning cans. Adjust so that it is within the range of ~6.8.

Therefore, the injection aqueous solution is usually adjusted to the acidic side, but it is usually sufficient to adjust the acidity to 3.5 to 5.5.

After stuffing the meat, it is heat sterilized by a conventional method, but at this time it does not turn black like in conventional methods.

Next, an example will be described.

Example 1 First, small-sized frozen Japanese squid weighing an average of 150 g per pie were thawed in water, the legs were removed, and the internal organs and cartilage were extracted and removed from the body.

Next, wash the torso and legs with water and drain, and the concentration is 0 at a temperature of 8.0.
．． It was immersed in an alkaline solution containing 45% phosphate, etc. (equal composition of sodium pyrophosphate and sodium pholyphosphate) to swell.

In this case, the amount of dipping liquid was 3 parts by weight per 1 part by weight of squid meat, and the temperature of the solution was 5° C., and the dipping time was 18 hours.

Next, after soaking, put the squid meat that you want to swell into a water tank and rinse with running water for 3 minutes.
The sample was soaked in water for 0 minutes to remove the immersion liquid and blood, and then drained.

Next, the squid meat was boiled for 6 minutes at 97°C in an acidic solution containing 0.3% phosphate (a mixture of 93% sodium metaphosphate and 7% sodium pyrophosphate) with a pH of 2.5. After cooling with water, the skin was peeled using a rotary peeler, washed with water, and drained.

Next, 130g of this meat was stuffed into No. 7 fruit cans (diameter 65.4mm x height 81.3mm), and further ll (
Inject 110g of water adjusted to 4.0, add 3.3g of salt and 0.3g of liquid, tighten and rotate.
- Heat sterilized at 120°C for 25 minutes in a vacuum oven and cooled with water.

When the canned meat was stored at room temperature for 30 days and then opened, the squid meat inside the can showed no black or gray discoloration, and could be deliciously served as a cooking ingredient in salads, boiled dishes, stir-fried dishes, etc. done.

Example 2 First, the frozen squid was thawed at a processing plant at the landing site, the legs were removed, the internal organs and cartilage were extracted and removed from the body, the squid was washed and drained, and only the body was refrozen and thawed again. Slice into 4mm wide squid rings using a slicer.

The squid rings were washed with water, drained, and then immersed in an alkaline solution containing phosphate and the like at a pH of 7.8 and a concentration of 0.25% to swell.

After this, an alkaline solution containing phosphate, etc. at a ratio of 2 parts by weight per 1 part by weight of squid rings is used, and the temperature of the solution is 8°C.
The immersion time was 12 hours, and the composition of the phosphate was 40% sodium pyrophosphate and 20% sodium polyphosphate.
, sodium acid pyrophosphate 4%, and others 36%.

Next, the swollen squid rings were placed in a water tank and exposed to running water for 20 minutes to remove the soaking liquid and blood, and then drained.

Next, the squid rings were boiled for 3 minutes at 97°C in an acidic solution containing 0.2% phosphate (a mixture of 93% sodium metaphosphate and 7% sodium pyrophosphate) at a pH of 3. Cooled and drained.

After that, put the squid rings in a No. 13 can (diameter 74.1 mm
65g of meat is stuffed into a 34.2mm (34.2mm in height), and 4.
45 g of water adjusted to 5.5 g was injected, and 3 g of common salt was added, followed by tightening.

This was sterilized using a rotary machine at 115° C. for 25 minutes and cooled with water.

When the above-mentioned canned food was opened after being stored at room temperature for 30 mouths, no black or gray discoloration was observed in the fleshy part of the squid rings, and the squid had its original texture, flavor, and color.
When used in marinades, vinegared dishes, and other dishes, it was found to be edible with a beautiful appearance and delicious taste.

As explained above in detail, the method of the present invention removes blood from the fleshy part of squid before heat sterilization and fixes the remaining body ions in the blood, while also fixing the remaining body ions in the blood during heat sterilization. Treated to prevent the formation of sulfides.

For this reason, it is possible to obtain canned squid that does not turn black or natural during heat sterilization after stuffing the meat, has no problems even when boiled in water, and retains its original flavor sufficiently.

Claims (1)

[Claims] 1. Prior to heat sterilizing the squid that is stuffed into cans during the production of canned squid, immerse the unheated squid in an alkaline solution containing phosphate with a pH of 7.5 to 9.5.
The meat of the squid is swollen to drain the blood, and then heated in an acidic solution so that the thickness of the squid meat is I) H5.4 or higher and as low as possible. A method for preventing blackening of squid in boiled canned squid, which is characterized by injecting an acidic aqueous solution so that the temperature of the squid meat is adjusted to 5.5 to 6.8.