阅读说明：本技术 一种牡蛎保鲜方法 (Oyster preservation method ) 是由 唐庆娟 李兆杰 卢娜 薛勇 薛长湖 王玉明 常耀光 于 2020-12-30 设计创作，主要内容包括：本发明涉及食品加工技术领域,尤其涉及一种牡蛎保鲜方法。本发明提供了一种牡蛎保鲜方法,包括以下步骤：(1)开壳取肉,将牡蛎开壳取肉,用清水清洗；(2)漂洗,将步骤(1)得到的牡蛎肉在漂洗液中漂洗8-12min；(3)超声处理,将步骤(2)得到的牡蛎肉进行超声波处理；(4)光动力杀菌,将步骤(3)得到的牡蛎肉放入光敏剂溶液中浸泡后立即取出,然后进行LED光源照射,完成杀菌过程。本发明提供的一种牡蛎保鲜方法,该方法能够有效提升牡蛎肉的品质,从而提高海牡蛎肉的食用品质,同时采用光动力杀菌方式可以对牡蛎进行有效的杀菌,明显延长牡蛎的货架期,提高经济效益。(The invention relates to the technical field of food processing, in particular to an oyster fresh-keeping method. The invention provides a method for preserving oysters, which comprises the following steps: (1) opening the shell to take out the meat, opening the shell of the oyster to take out the meat, and cleaning with clear water; (2) rinsing, namely rinsing the oyster meat obtained in the step (1) in a rinsing solution for 8-12 min; (3) performing ultrasonic treatment, namely performing ultrasonic treatment on the oyster meat obtained in the step (2); (4) and (4) performing photodynamic sterilization, namely putting the oyster meat obtained in the step (3) into a photosensitizer solution for soaking, immediately taking out, and then performing LED light source irradiation to finish the sterilization process. According to the oyster preservation method provided by the invention, the quality of oyster meat can be effectively improved, so that the edible quality of sea oyster meat is improved, and meanwhile, the oyster can be effectively sterilized by adopting a photodynamic sterilization mode, so that the shelf life of the oyster is obviously prolonged, and the economic benefit is improved.)

1. The oyster preservation method is characterized by comprising the following steps:

(1) opening the shell to take out meat

Opening the shell of the oyster to take out the meat, and cleaning with clear water;

(2) rinsing

Rinsing the oyster meat obtained in the step (1) in a rinsing liquid for 8-12 min;

(3) ultrasonic treatment

Carrying out ultrasonic treatment on the oyster meat obtained in the step (2);

(4) photodynamic sterilization

And (4) soaking the oyster meat obtained in the step (3) in a photosensitizer solution, immediately taking out, and then irradiating by using an LED light source to finish the sterilization process.

2. The oyster freshness keeping method according to claim 1, wherein in the step (2), the rinsing liquid comprises the following raw materials in parts by weight: 0.35-0.45 part of tea polyphenol, 1-2 parts of sodium chloride, 0.5-0.75 part of citric acid, 0.2-0.25 part of polyphosphate and 5-7 parts of trehalose.

3. The method for preserving oysters according to claim 1, wherein in the step (3), the ultrasonic treatment parameters are set as: 175-225W, 25-30 KHz.

4. The method for preserving oysters according to claim 1, wherein in the step (3), the ultrasonic treatment mode is as follows: performing ultrasound for 1min, pausing for 1min, and repeating for 5-7 times.

5. The method for preserving oysters according to claim 1, wherein in the step (4), the photosensitizer is curcumin and talaporfin sodium.

6. The method for preserving oysters according to claim 5, wherein the concentration of the photosensitizer is 20-40 μmol/L; the concentration ratio of the curcumin to the talaporfin sodium in the water is 1-2: 1-2.

7. The method for preserving oysters according to claim 5 or 6, wherein the photosensitizers curcumin and talaporfin sodium are food grade with purity above 95%.

8. The method for preserving oysters according to claim 1, wherein in the step (4), the LED light source is a red light source or a blue light source.

9. The oyster freshness keeping method according to claim 1, wherein the LED light source irradiation is: firstly, irradiating for 30-40s by using a blue light source, and then irradiating for 30-40s by using a red light source.

10. The method as claimed in claim 9, wherein the wavelengths of the LED blue light source and the LED red light source are 460nm and 680nm, respectively.

Technical Field

The invention relates to the technical field of food processing, in particular to an oyster fresh-keeping method.

Background

Oyster (ostragigastnub) is commonly called oyster and oyster, belongs to the phylum mollusca, class bivalvia, order pearl oyster, is the first cultured shellfish in the world, is one of the important marine biological resources available to human beings, and is a globally distributed variety. The oyster is not only fresh and delicious in meat and rich in nutrition, but also has unique health care function and medicinal value, and is a seafood with high nutritional value. Due to self-pollution of cultivation production, land-source pollution and the like, the bacteria in the oysters are relatively complex and are extremely easy to decay. Therefore, the sale range of the fresh oysters is limited to coastal provinces. How to effectively prolong the shelf life of the fresh oysters and expand the sales range of the fresh oysters becomes a topic of great attention. 85-90% of the oyster yield in China is mainly used for fresh marketing with shells and barbecue eating, so that effective sterilization of oysters is necessary.

For example, CN201811255805.5 discloses a technique for sterilizing oysters, in which fresh oysters are cleaned and sterilized with ozone water, but the preparation and storage of ozone are complicated and the production cost is high. Chinese invention CN201510803314.X discloses a method for preparing smoked oyster cans, which comprises the steps of placing oyster meat in saline water for ultrahigh pressure treatment, wherein the oyster ultrahigh pressure treatment sterilization and preservation technology has little influence on the quality of oysters, can keep the original taste of the oysters, but has expensive equipment and high production cost. Chinese invention CN200810219126.2 discloses a method for processing instant high-moisture oyster food, in which oyster meat is immersed in boiled salt water for blanching and dehydration, but the processed oyster cannot be eaten fresh.

Photodynamic sterilization is a new technology which is developed internationally at present, is successfully applied to the treatment of tumors, and becomes a fourth therapy except for operation, radiotherapy and chemotherapy. The basic principle is that a Photosensitizer (PS) crosses from a ground state to a triplet state through a very short-lived singlet state under irradiation of a suitable light source. The light excited triplet photosensitizer can produce two kinds of reaction to produce a series of toxic active products represented by singlet oxygen, which can react with cell or microbe's phospholipid, nucleic acid, protein and other biological macromolecules to destroy biomembrane structure or other functional units and kill cell or microbe, so as to reach the therapeutic effect. In the prior art, the method is mostly applied to the field of medicine, and the application of photodynamic sterilization to oyster preservation is not available.

Therefore, how to provide a method for keeping oysters fresh by utilizing the photodynamic sterilization technology to prolong the shelf life of the oysters, and the method is simple and low in production cost, which is a problem to be solved urgently by technical personnel in the field.

Disclosure of Invention

In view of the above, the invention provides the oyster preservation method which is simple to operate and can obviously improve the quality of oysters and effectively prolong the shelf life of the oysters.

In order to achieve the purpose, the invention adopts the following technical scheme:

a method for keeping oysters fresh comprises the following steps:

(1) opening the shell to take out meat

Opening the shell of the oyster to take out the meat, and cleaning with clear water;

(2) rinsing

Rinsing the oyster meat obtained in the step (1) in a rinsing liquid for 8-12 min;

(3) ultrasonic treatment

Carrying out ultrasonic treatment on the oyster meat obtained in the step (2);

(4) photodynamic sterilization

And (4) soaking the oyster meat obtained in the step (3) in a photosensitizer solution, immediately taking out, and then irradiating by using an LED light source to finish the sterilization process.

Preferably, in the step (2), the rinsing liquid comprises the following raw materials in parts by weight: 0.35-0.45 part of tea polyphenol, 1-2 parts of sodium chloride, 0.5-0.75 part of citric acid, 0.2-0.25 part of polyphosphate and 5-7 parts of trehalose.

Further preferably, the phosphate polymer is one of sodium pyrophosphate, sodium tripolyphosphate and sodium polyphosphate.

Further preferably, in the step (2), the rinsing liquid comprises the following raw materials in parts by weight: 0.4 part of tea polyphenol, 1.5 parts of sodium chloride, 0.6 part of citric acid, 0.225 part of polyphosphate and 6 parts of trehalose.

Preferably, in the step (3), the ultrasonic processing parameters are set as follows: 175-225W, 25-30 KHz.

Further preferably, in the step (3), the ultrasonic processing parameters are set as follows: 200W, 28 KHz.

Preferably, in the step (3), the ultrasonic treatment method is: performing ultrasound for 1min, pausing for 1min, and repeating for 5-7 times.

More preferably, in the step (3), the ultrasonic treatment method is: sonication for 1min, pausing for 1min, repeating for 6 times.

Preferably, in the step (4), the photosensitizer is curcumin and talaporfin sodium.

Preferably, the concentration of the photosensitizer is 20-40 mu mol/L; the concentration ratio of the curcumin to the talaporfin sodium in the water is 1-2: 1-2.

Further preferably, the concentration of the photosensitizer is 30 mu mol/L; the concentration ratio of the curcumin to the talaporfin sodium in the water is 1: 1.

Preferably, the photosensitizer curcumin and talaporfin sodium are food grade, and the purity is more than 95%.

Preferably, in the step (4), the LED light source is a red light source or a blue light source.

Preferably, the LED light source irradiates: irradiating with blue light for 30-40s, and irradiating with red light for 30-40 s.

Further preferably, the LED light source irradiates: blue light was used to illuminate 35s first, and then red light was used to illuminate 35 s.

Preferably, the wavelength ranges of the LED blue light source and the LED red light source are 460nm and 680nm respectively at 450-.

Further, curcumin is a natural diketone compound extracted from rhizomes of plants of curcuma genus of zingiberaceae family, is orange yellow crystalline powder, and is mainly used for coloring sausage, can, marinated products and other products in food production. Curcumin has wide pharmacological activities of anti-inflammation, antioxidation, anti-infection, anti-tumor, anticoagulation, anti-atherosclerosis and the like, and has low toxicity and weak adverse reaction. Is one of the popular natural edible pigments in the world at present and is a food additive which is licensed by the world health organization and multiple countries.

Talaporfin sodium is a natural water-soluble photosensitizer extracted from plant chlorophyll, is dark blue-green powder, has the advantages of single composition, small absorption wavelength (664nm), small skin phototoxicity, short administration and illumination time and the like, is a hot spot for treating tumor diseases by photodynamic therapy as the photosensitizer, and is mainly used for coloring products such as beverages, cans, cakes, biscuits and the like.

According to the technical scheme, compared with the prior art, the invention has the following beneficial effects:

1. the method for preserving oysters is simple to operate, can effectively improve the meat quality of oyster meat, so that the edible quality of sea oyster meat is improved, and meanwhile, the shelf life of oysters can be remarkably prolonged by adopting a photodynamic sterilization mode to effectively sterilize the oyster meat, so that the economic benefit is improved.

2. During storage, oysters undergo two forms of fat change, mainly oxidation and hydrolysis. The fat hydrolysis reaction is that the viscera of the oyster contain fat hydrolase and phospholipid hydrolase, the enzymes can cause the hydrolysis of fat during the storage process of the oyster, the free acid generated after the hydrolysis can promote the denaturation of protein, and the speed of the free acid combined with oxygen is higher than that of the fatty acid combined with the oxygen, so that micromolecular aldehyde and alcohol are generated more and more quickly, and the fragrance and the quality of the oyster are seriously affected.

3. Oyster has an increasing trend of amino acids during storage, and the main reason is that proteins generate amino acids, peptides and volatile nitrogen in the decomposition process. When the oysters enter the autolysis period, microorganisms in the oysters start to propagate in a large amount to generate volatile basic nitrogen such as ammonia, methylamine and trimethylamine, and when the volatile basic nitrogen is accumulated to a certain degree, the oysters enter the putrefaction period and cannot be eaten. The trehalose added in the invention forms a protective film on the surface of a cell membrane under the environment of high osmotic pressure, effectively keeps water and protects protein molecules from being inactivated without denaturation.

4. The addition of citric acid can prevent the browning of oysters, and has good fresh-keeping and color-protecting effects.

5. The polymerized phosphate has an antioxidant effect because the acid phosphate integrates metal ions and the metal ions which promote the oxidation of the oil are deactivated, thereby reducing the oxidation of the oysters.

6. The invention not only is an effective cleaning process for oysters by an intermittent ultrasonic process, but also has a certain killing effect on bacteria and microorganisms in food due to the existence of the ultrasonic wave energy field. Meanwhile, it is a tenderization process of oyster meat, but if continuous ultrasound is performed, the oyster meat becomes too loose.

7. The invention combines two natural photosensitizers curcumin and talaporfin sodium, and is matched with the corresponding visible monochromatic light source blue light and red light for use, thereby being a new formula and new application, and being a safe, economic and reliable sterilization method with broad-spectrum sterilization effect. The photosensitizer curcumin and talaporfin sodium belong to food-grade photosensitizers, are safe and nontoxic, are low in cost, belong to visible light sources, and are safe and reliable.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

A method for keeping oysters fresh comprises the following steps:

(1) opening the shell to take out meat

Opening the shell of the oyster to take out the meat, and cleaning with clear water;

(2) rinsing

Rinsing the oyster meat obtained in the step (1) in a rinsing liquid for 8 min; the rinsing liquid comprises the following raw materials in parts by weight: 0.35 part of tea polyphenol, 1 part of sodium chloride, 0.5 part of citric acid, 0.2 part of polyphosphate and 5 parts of trehalose.

(3) Ultrasonic treatment

Carrying out ultrasonic treatment on the oyster meat obtained in the step (2); the ultrasonic treatment parameters are set as follows: 175W, 25 KHz; the ultrasonic treatment method comprises the following steps: sonication for 1min, pausing for 1min, and repeating for 5 times.

(4) Photodynamic sterilization

Soaking the oyster meat obtained in the step (3) in a curcumin and talaporfin sodium (food grade, purity is more than 95%) solution, immediately taking out, then irradiating for 30s by using a blue light source (450-680 nm), and then irradiating for 30s by using a red light source (620-680nm), thereby completing the sterilization process; the concentration of the photosensitizer is 20 mu mol/L; the concentration ratio of the curcumin to the talaporfin sodium in the water is 1: 1.

Example 2

A method for keeping oysters fresh comprises the following steps:

(1) opening the shell to take out meat

Opening the shell of the oyster to take out the meat, and cleaning with clear water;

(2) rinsing

Rinsing the oyster meat obtained in the step (1) in a rinsing solution for 12 min; the rinsing liquid comprises the following raw materials in parts by weight: 0.45 part of tea polyphenol, 2 parts of sodium chloride, 0.75 part of citric acid, 0.25 part of polyphosphate and 7 parts of trehalose.

(3) Ultrasonic treatment

Carrying out ultrasonic treatment on the oyster meat obtained in the step (2); the ultrasonic treatment parameters are set as follows: 225W, 30 KHz; the ultrasonic treatment method comprises the following steps: sonication for 1min, pausing for 1min, and repeating for 7 times.

(4) Photodynamic sterilization

Soaking the oyster meat obtained in the step (3) in a curcumin and talaporfin sodium (food grade, purity is more than 95%) solution, immediately taking out, then irradiating for 40s by using a blue light source (450-680 nm), and then irradiating for 40s by using a red light source (620-680nm), thereby completing the sterilization process; the concentration of the photosensitizer is 40 mu mol/L; the concentration ratio of the curcumin to the talaporfin sodium in the water is 1: 1.

Example 3

A method for keeping oysters fresh comprises the following steps:

(1) opening the shell to take out meat

Opening the shell of the oyster to take out the meat, and cleaning with clear water;

(2) rinsing

Rinsing the oyster meat obtained in the step (1) in a rinsing liquid for 10 min; the rinsing liquid comprises the following raw materials in parts by weight: 0.4 part of tea polyphenol, 1.5 parts of sodium chloride, 0.625 part of citric acid, 0.225 part of polyphosphate and 6 parts of trehalose.

(3) Ultrasonic treatment

Carrying out ultrasonic treatment on the oyster meat obtained in the step (2); the ultrasonic treatment parameters are set as follows: 200W, 28 KHz; the ultrasonic treatment method comprises the following steps: sonication for 1min, pausing for 1min, repeating for 6 times.

(4) Photodynamic sterilization

Soaking the oyster meat obtained in the step (3) in a curcumin and talaporfin sodium (food grade, purity is more than 95%) solution, immediately taking out, then irradiating for 35s by using a blue light source (450-680 nm), and then irradiating for 35s by using a red light source (620-680nm), thereby completing the sterilization process; the concentration of the photosensitizer is 30 mu mol/L; the concentration ratio of the curcumin to the talaporfin sodium in the water is 1: 1.

Example 4

A method for keeping oysters fresh comprises the following steps:

(1) opening the shell to take out meat

Opening the shell of the oyster to take out the meat, and cleaning with clear water;

(2) rinsing

Rinsing the oyster meat obtained in the step (1) in a rinsing liquid for 10 min; the rinsing liquid comprises the following raw materials in parts by weight: 0.4 part of tea polyphenol, 1.5 parts of sodium chloride, 0.625 part of citric acid, 0.225 part of polyphosphate and 6 parts of trehalose.

(3) Ultrasonic treatment

Carrying out ultrasonic treatment on the oyster meat obtained in the step (2); the ultrasonic treatment parameters are set as follows: 200W, 28 KHz; the ultrasonic treatment method comprises the following steps: sonication for 1min, pausing for 1min, repeating for 6 times.

Example 5

A method for keeping oysters fresh comprises the following steps:

(1) opening the shell to take out meat

Opening the shell of the oyster to take out the meat, and cleaning with clear water;

(2) rinsing

Rinsing the oyster meat obtained in the step (1) in a rinsing liquid for 10 min; the rinsing liquid comprises the following raw materials in parts by weight: 0.4 part of tea polyphenol, 1.5 parts of sodium chloride, 0.625 part of citric acid, 0.225 part of polyphosphate and 6 parts of trehalose.

(3) Ultrasonic treatment

Carrying out ultrasonic treatment on the oyster meat obtained in the step (2); the ultrasonic treatment parameters are set as follows: 200W, 28 KHz; the ultrasonic treatment method comprises the following steps: sonication for 1min, pausing for 1min, repeating for 6 times.

(4) Soaking the oyster meat obtained in the step (3) in a curcumin and talaporfin sodium (food grade, purity is more than 95%) solution, and then immediately taking out the oyster meat, wherein the concentration of the photosensitizer is 30 mu mol/L; the concentration ratio of the curcumin to the talaporfin sodium in the water is 1: 1.

Example 6

The fresh-keeping capacity of the oyster fresh-keeping method is experimentally verified.

Wherein oysters treated according to the method of example 3 were used as group 1; oysters without any treatment were used as group 2; oysters treated according to the method of example 4 were used as group 3; example 5 the oysters obtained were treated as group 4; according to the method of example 3, but without soaking by using photosensitizer solution, the oysters irradiated and treated by LED light source are directly used as the 5 th group, each group is provided with 3 parallel experiments, each group of treated oysters are placed in a constant temperature incubator at 25 ℃ for 48h, the number of colonies of each group is counted, the results of the three parallel experiments of each group are averaged, and the results are shown in Table 1:

TABLE 1

	Number of colonies (cfu/g)
		Group 1	1.00×103
Group 2	2.05×105
		Group 3	1.71×105
Group 4	7.00×104
		Group 5	1.61×105

As can be seen from the data in Table 1, the colony count of the oysters treated by the method is significantly less than that of the oysters in groups 2, 3, 4 and 5, which indicates that the oyster sterilizing agent has excellent sterilizing effect; the colony number of the group 4 is obviously less than that of the group 2, which indicates that the photosensitizer has a certain bactericidal effect; the comparison of the data in group 3 with that in group 2 shows that the rinsing process or ultrasonic process of the present invention also has a certain sterilization effect; the comparison between the 3 rd group and the 5 th group shows that the influence of the pure LED light source irradiation treatment on the sterilization effect is small.

Example 7

By a one-factor experiment, oysters obtained from the treatment group and the control group were stored in a refrigerator at-4 ℃ for 10 days by the method of example 3 as treatment group 1 and example 3 but not rinsed as treatment group 2 and untreated oysters as control group, and after thawing, the oysters were observed for appearance, color, odor, morphological integrity, and the like, immediately taken out by boiling with brine, and tasted for flavor, umami, mouthfeel elasticity, and the like, and the results are shown in table 2:

TABLE 2

Therefore, the method for preserving oysters can prolong the shelf life of the oysters, and can keep the original color, taste, shape and integrity of the oysters even if the oysters are frozen at low temperature for a period of time. It can be seen from the comparison between the treatment group 1 and the treatment group 2 that the oysters after the rinsing process can maintain the elasticity and good taste of the oyster meat for a long time, and the oysters without the rinsing process lose the taste after eating, but have no peculiar smell, and although the normal eating of the oyster meat is not affected, the oyster meat has a large sensory effect, and the selling process of the oysters is further affected.

Example 8

In a one-factor experiment, oysters obtained by the treatment method of example 3 were used as an experimental group and the treatment method of example 3 was used, but the ultrasonic treatment was replaced with continuous ultrasonic treatment for 6min, and other experimental conditions were the same as in example 3, and as a control group, the oysters were observed for appearance, color, smell, morphological integrity and other items, and then immediately fished out by boiling in saline water, and items such as flavor, umami, mouthfeel elasticity and the like were tasted, and the results are shown in table 3:

TABLE 3

The invention utilizes ultrasonic technology to treat oysters, mainly utilizes the high-frequency mechanical shock wave generated by an ultrasonic generator to impact meat to generate forced vibration, so that connective tissues and myofibrils are broken, lysosomes are broken at the same time, cathepsin is released, the tenderization effect of oyster meat is achieved, and the oyster meat is tenderized by adopting intermittent ultrasonic treatment without being too soft, so that the oyster meat treated by the method can keep the original flavor of the oyster for a long time.

The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.