阅读说明：本技术 一种防止金枪鱼白肉氧化的保存方法 (Preservation method for preventing tuna white meat from being oxidized ) 是由 谢绍泰 于 2020-12-31 设计创作，主要内容包括：本发明公开了一种防止金枪鱼白肉氧化的保存方法。其保存方法将蒸煮后的金枪鱼白肉用保鲜袋封装并抽真空,加热进行热收缩,降温,急冻,最后冷藏保存。本发明通过将金枪鱼白肉保鲜袋封装并抽真空,热收缩后保鲜袋与鱼肉完全贴合防止保鲜袋破损；并进行降温、急冻防止金枪鱼白肉中脂肪发生氧化反应,最后冷藏经一步放置金枪鱼白肉氧化酸败；金枪鱼白肉储存期最长为12月。(The invention discloses a preservation method for preventing tuna white meat from being oxidized. The preservation method comprises packaging cooked tuna white meat with fresh-keeping bag, vacuumizing, heating for thermal contraction, cooling, rapidly freezing, and cold preserving. According to the method, the tuna white meat freshness protection package is packaged and vacuumized, and the freshness protection package is completely attached to the fish meat after thermal shrinkage, so that the freshness protection package is prevented from being damaged; cooling, quickly freezing to prevent oxidation reaction of fat in the tuna white meat, and refrigerating for one-step placing the tuna white meat to be oxidized and rancidity; the shelf life of tuna white meat is 12 months at most.)

1. A preservation method for preventing tuna white meat from being oxidized is characterized in that the cooked tuna white meat is packaged by a freshness protection package, vacuumized, heated for thermal contraction, cooled, frozen quickly, and finally refrigerated for preservation.

2. The preservation method for preventing tuna white meat from being oxidized according to claim 1, wherein the freshness protection package is a multilayer co-extruded heat-shrinkable package.

3. The preservation method for preventing tuna white meat from being oxidized according to claim 2, wherein the multilayer co-extruded heat-shrinkable bag comprises a heat-sealing layer, a core layer and a surface layer in sequence from inside to outside; the heat-sealing layer, the core layer and the surface layer are mutually attached through an adhesive.

4. The preservation method for preventing tuna white meat from oxidation according to claim 3, wherein the heat-seal layer and the surface layer are polyethylene, the core layer is polyamide, and the adhesive is a bonding resin.

5. The preservation method for preventing tuna white meat from oxidation according to claim 1, wherein the degree of vacuum of the vacuum is not less than 0.9 Mpa.

6. The preservation method for preventing oxidation of tuna white meat according to claim 1, wherein the heat shrinking is immersing the sealed freshness protection package in hot water; the temperature of the hot water is 70-80 deg.C, and the soaking time is not less than 3 min.

7. The preservation method for preventing tuna white meat from being oxidized according to claim 1, wherein the temperature is reduced to 10 ℃ or less by putting the heat-shrunk tuna white meat in ice water at 0 ℃ or less.

8. The preservation method for preventing tuna white meat from being oxidized according to claim 1, wherein the quick freezing is to place the cooled freshness protection package at a temperature of-38 ℃ or lower for 6 hours or more.

9. The preservation method for preventing oxidation of tuna white meat according to claim 1, wherein the temperature of the tuna white meat after the rapid freezing is less than or equal to-20 ℃.

10. The preservation method for preventing oxidation of tuna white meat according to claim 1, wherein the temperature for cold preservation is ≦ -20 ℃.

Technical Field

The invention relates to the field of food processing, in particular to a preservation method for preventing tuna white meat from being oxidized.

Background

The tuna meat is tender and delicious, has high protein content, is rich in DHA, EPA and other polyunsaturated fatty acids with biological activity, and is one of three kinds of nutritional fish recommended by the international society for nutrition; tuna is a kind of fish with high value, has large capture amount, is one of important fishes in ocean fishery, and has great market potential. Tuna is mainly processed into dry, canned and frozen products, wherein the canned food yield is the greatest.

In the production of the prior canned tuna, the tuna meat is easy to accumulate due to the reasons of time, manpower shortage, limited space and the like, and the high fatty acid content of the tuna meat is easy to cause fat oxidation, so that the tuna meat is yellow, peculiar smell and even putrefaction; resulting in increased costs and reduced efficiency in the production process.

Due to the original production process, the cooked tuna meat is produced, the scraped white meat is packaged by a freshness protection package and then stored in a refrigeration house for temporary storage, and is unfrozen when production is needed; when the production orders are few, the storage amount of the tuna white meat is large; however, the storage method has short shelf life, and the oxidative deterioration is started to cause loss after the storage is usually carried out for 1 month, so that direct economic loss is generated.

Disclosure of Invention

The invention provides a preservation method for preventing tuna white meat from being oxidized, which can greatly prolong the storage time of the tuna white meat.

The purpose of the invention is realized by the following technical scheme:

a preservation method for preventing oxidation of tuna white meat comprises packaging cooked tuna white meat with fresh-keeping bag, vacuumizing, heating for thermal contraction, cooling, rapidly freezing, and cold preserving.

Preferably, the freshness protection package is a multilayer co-extrusion heat-shrinkable package.

Further preferably, the multilayer co-extruded heat shrinkable bag sequentially comprises a heat sealing layer, a core layer and a surface layer from inside to outside; the heat-sealing layer, the core layer and the surface layer are mutually attached through an adhesive. The heat-sealing layer and the surface layer are made of polyethylene, the core layer is made of polyamide, and the adhesive is bonding resin.

Preferably, the vacuum degree of the vacuum pumping is more than or equal to 0.9 MPa.

Preferably, the heat shrinkage is to soak the sealed freshness protection package in hot water; the temperature of the hot water is 70-80 deg.C, and the soaking time is not less than 3 min.

Preferably, the temperature reduction is to reduce the temperature of the heat-shrunk product to be less than or equal to 10 ℃ in ice water with the temperature of less than or equal to 0 ℃.

Preferably, the quick freezing is to place the cooled freshness protection package at a temperature of less than or equal to-38 ℃ for more than or equal to 6 hours.

Preferably, the temperature of the white meat of the tuna after the quick freezing is less than or equal to-20 ℃.

Preferably, the temperature for refrigerated storage is ≦ -20 ℃.

According to the method, the tuna white meat freshness protection package is packaged and vacuumized, and the freshness protection package is completely attached to the fish meat after thermal shrinkage, so that the freshness protection package is prevented from being damaged; cooling, quickly freezing to prevent oxidation reaction of fat in the tuna white meat, and refrigerating for one-step placing the tuna white meat to be oxidized and rancidity; the shelf life of tuna white meat is 12 months at most.

Detailed Description

The following specific examples are provided to further illustrate the present invention so that those skilled in the art may better understand the invention and practice it, but the examples are not intended to limit the invention. Other various modifications, substitutions and alterations of the above-described structures of the present invention will occur to those skilled in the art without departing from the basic technical spirit of the invention as described herein.

In the present invention, PE means polyethylene; PP refers to polypropylene; LDPE is low density polyethylene; PA refers to polyamide; PETE refers to polyethylene terephthalate; all plastics are food grade.

The multilayer co-extruded heat shrinkable film is divided into three layers from inside to outside, namely a heat sealing layer directly contacting the fish meat, a core layer and an outermost surface layer; wherein the surface layer and the core layer, and the core layer and the heat sealing layer are bonded together by adhesives. The heat sealing layer is made of PE; the core layer is made of PA; the surface layer is made of PE; tie (adhesive resin) is used as the adhesive. The heat-sealing layer, the core layer and the surface layer are completely attached without gaps before heat sealing.

Example 1 effect of freshness protection package on shelf life of tuna white meat.

In order to verify whether different freshness protection packages have an influence on the storage period of the tuna white meat, the following experiment was set:

(1) taking the same tuna white meat which is steamed, peeled, boned and red meat removed, dividing into 5 pieces, and recording as No. 1-5; respectively put into freshness protection bags made of different materials.

(2) And (3) vacuumizing the freshness protection package filled with the tuna white meat by using a vacuum machine until the vacuum degree reaches 0.9MPa, and sealing.

(3) And (3) soaking the freshness protection package obtained in the step (2) in hot water at 80 ℃ for 3min for thermal shrinkage, and then cooling the freshness protection package in ice water at 0 ℃ to 10 ℃.

(4) Keeping the temperature within the range of-16 deg.C to-19 deg.C, standing for a period of time, and recording the oxidation condition of tuna white meat with different labels, as shown in Table 1.

TABLE 1

And (4) conclusion: compared with the preservation bag made of other materials, the preservation condition of the multilayer co-extrusion heat-shrinkable bag is best, and oxidation does not begin until the 55 th day.

Example 2 effect of vacuum on shelf life of tuna white meat.

To verify whether different vacuum levels have an effect on the shelf life of tuna white meat, the following experiment was set up:

(1) taking the same tuna white meat which is steamed, peeled, boned and red meat removed, dividing into 4 pieces, and recording as No. 1-4; respectively filling into multilayer co-extruded thermal shrinkage bags.

(2) And (3) vacuumizing the freshness protection package filled with the tuna white meat by using a vacuum machine, and sealing after the freshness protection package is vacuumized to a corresponding vacuum degree.

(3) And (3) soaking the freshness protection package obtained in the step (2) in hot water at 80 ℃ for 3min for thermal shrinkage, and then cooling the freshness protection package in ice water at 0 ℃ to 10 ℃.

(4) Keeping the temperature within the range of-16 deg.C to-19 deg.C, standing for a period of time, and recording the oxidation status of tuna white meat with different labels, as shown in Table 2.

TABLE 2

	Number 1	Number 2	No. 3	Number 4
					Degree of vacuum	0.3Mpa	0.5Mpa	0.9Mpa	1.2Mpa
Oxidation on day 3	Is free of	Is free of	Is free of	Is free of
					Oxidation on day 5	Is provided with	Is free of	Is free of	Is free of
Oxidation on day 10	Is provided with	Is free of	Is free of	Is free of
					Oxidation at day 15	Is provided with	Is provided with	Is free of	Is free of

And (4) conclusion: when the vacuum degree reaches 0.9Mpa, the lower the vacuum degree is, the faster the oxidation start time is, and after the vacuum degree reaches 0.9Mpa, the further increase of the vacuum degree does not prolong the oxidation start time; therefore, the lower limit of the vacuum degree is selected to be 0.9 MPa.

Example 3 effect of heat shrinkage on shelf life of tuna white meat.

To verify whether different heat shrinkage temperatures, times have an effect on the shelf life of tuna white meat, the following experiments were set up:

(1) taking the same tuna white meat which is steamed, peeled, boned and red meat removed, dividing into 6 pieces, and recording as No. 1-6; respectively filling into multilayer co-extruded thermal shrinkage bags.

(2) And (3) vacuumizing the freshness protection package filled with the tuna white meat by using a vacuum machine until the vacuum degree reaches 0.9MPa, and sealing.

(3) And (3) soaking the freshness protection package obtained in the step (2) in hot water at different temperatures for a period of time, and then putting the freshness protection package in ice water at the temperature of 0 ℃ to cool the freshness protection package to 10 ℃.

(4) Keeping the temperature within the range of-16 deg.C to-19 deg.C, standing for a period of time, and recording the oxidation status of tuna white meat with different labels, as shown in Table 3.

TABLE 3

And (4) conclusion: when the temperature is within 70-80 ℃, the oxidation starting time is longest, and the oxidation starting time is shortened by over-low and over-high temperatures; after the thermal shrinkage time reaches 3min, the oxidation starting time cannot be prolonged by continuously delaying the thermal shrinkage time; therefore, the heat shrinkage water temperature is selected to be 70-80 ℃, and the heat shrinkage time is more than or equal to 3 min.

Example 4 effect of temperature reduction on shelf life of tuna white meat.

In order to verify whether the temperature and time of different cooling have influence on the storage period of the white tuna meat, the following experiment is set:

(1) taking the same tuna white meat which is steamed, peeled, boned and red meat removed, dividing into 5 pieces, and recording as No. 1-5; respectively filling into multilayer co-extruded thermal shrinkage bags.

(2) And (3) vacuumizing the freshness protection package filled with the tuna white meat by using a vacuum machine until the vacuum degree reaches 0.9MPa, and sealing.

(3) And (3) soaking the freshness protection package obtained in the step (2) in hot water at 80 ℃ for 3min for thermal shrinkage, then placing the freshness protection package in an ice-water mixture at 0 ℃ for cooling for a certain time, and recording the surface temperature of the fish meat.

(4) The tuna white meat was kept at a temperature ranging from-16 ℃ to-19 ℃ for a period of time and the oxidation of the tuna white meat was recorded for different markers as shown in table 4.

TABLE 4

	Number 1	Number 2	No. 3	Number 4	Number 5
						Water temperature (. degree.C.)	0	0	0	0	0
Time (min)	3	5	10	15	20
						Surface temperature (. degree.C.) of fish meat	20	15	10	5	0
Oxidation on day 10	Is free of	Is free of	Is free of	Is free of	Is free of
						Oxidation at day 15	Is free of	Is free of	Is free of	Is free of	Is free of
Oxidation on day 25	Is provided with	Is provided with	Is free of	Is free of	Is free of
						Oxidation at day 30	Is provided with	Is provided with	Is free of	Is free of	Is free of

And (4) conclusion: when the surface temperature of the fish meat after vacuum heat shrinkage in a fish packaging bag is reduced to below 10 ℃, the oxidation starting time is longest, then the temperature is 10 ℃, 5 ℃ and 0 ℃, the effect of prolonging the oxidation time is not obvious, and the surface temperature of the fish meat is selected to be less than or equal to 10 ℃ for the reason of production efficiency.

Example 5 effect of quick freezing on shelf life of tuna white meat.

In order to verify whether different quick freezing temperatures and times have influence on the storage period of the white tuna meat, the following experiment is set:

(1) taking the same tuna white meat which is steamed, peeled, boned and red meat removed, dividing into 6 pieces, and recording as No. 1-6; respectively filling into multilayer co-extruded thermal shrinkage bags.

(2) And (3) vacuumizing the freshness protection package filled with the tuna white meat by using a vacuum machine until the vacuum degree reaches 0.9MPa, and sealing.

(3) And (3) soaking the freshness protection package obtained in the step (2) in hot water at 80 ℃ for 3min for thermal shrinkage, and then cooling the freshness protection package in ice water at 0 ℃ to 10 ℃.

(4) Placing the cooled freshness protection package into a quick freezing warehouse for quick freezing, setting different quick freezing temperatures and time, recording the central temperature of the freshness protection package after quick freezing, and then placing the freshness protection package into the cold warehouse for storage; the storage temperature of the cold storage is-18 ℃; and the oxidation of the tuna white meat was recorded as shown in table 5.

TABLE 5

Number 1

Number 2

No. 3

Number 4

Number 5

Number 6

Temperature of quick freezing (. degree. C.)

-30

-38

-38

-38

-42

-42

Quick freezing time (h)

6

5

6

7

6

6

Center temperature (. degree. C.)

-15.2

-18.1

-20.3

-22.5

-20.8

-20.6

Oxidation on day 3

Is free of

Is free of

Is free of

Is free of

Is free of

Is free of

Oxidation on day 5

Is free of

Is free of

Is free of

Is free of

Is free of

Is free of

Oxidation on day 10

Is provided with

Is free of

Is free of

Is free of

Is free of

Is free of

Oxidation at day 15

Is provided with

Is provided with

Is free of

Is free of

Is free of

Is free of

And (4) conclusion: the temperature of the quick freezing warehouse is higher than-38 ℃, and the quick freezing time is less than 6 h. Finally, the central temperature of the tuna white meat is higher than-20 ℃; this results in a shorter oxidation start time; when the central temperature is less than or equal to minus 20 ℃, the further reduction of the central temperature can not lead to the prolongation of the oxidation starting time, thereby limiting the quick freezing temperature of the tuna to be less than or equal to minus 38 ℃, the quick freezing time to be more than or equal to 6 hours and the central temperature of the fish to be less than or equal to minus 20 ℃.

Example 6 the experiment was validated.

To verify the parameters obtained in examples 1 to 5, the following experiments were set up:

(1) and putting the white tuna meat which is steamed, peeled, boned and red meat removed in the same piece into a multilayer co-extrusion thermal contraction bag fresh-keeping bag.

(2) And (3) vacuumizing the freshness protection package filled with the tuna white meat by using a vacuum machine until the vacuum degree reaches 0.9MPa, and sealing.

(3) And (3) soaking the freshness protection package obtained in the step (2) in hot water at 80 ℃ for 3min for thermal shrinkage, and then cooling the freshness protection package in ice water at 0 ℃ to 10 ℃.

(4) Placing the cooled freshness protection package into a quick freezing warehouse for quick freezing at the quick freezing temperature of minus 36 ℃ for 6 hours, recording the central temperature of the freshness protection package after quick freezing, and then placing the freshness protection package into the cold warehouse for storage; the storage temperature of the cold storage is-19 ℃; and the oxidation of the tuna white meat was recorded.

The results showed that the center temperature of the bag after the quick freezing was-18 ℃ and the tuna white meat began to oxidize after 367 days.