阅读说明：本技术 一种超声辅助低温加热制备腌腊鱼的方法 (Method for preparing salted and cured fish by ultrasonic-assisted low-temperature heating ) 是由 周绪霞 储雨姗 丁玉庭 顾赛麒 吕飞 朱士臣 于 2019-11-20 设计创作，主要内容包括：本发明涉及一种超声辅助低温加热制备腌腊鱼的方法。所述方法为,经预处理、腌制、干燥后真空包装的腌腊鱼浸于超声池中进行超声处理,样品加入超声池后开启循环恒温器加热循环系统,当水温上升到40～50℃时关闭加热器并开启超声装置进行超声处理,超声功率和频率分别控制500～700W和18～20kHz,超声时间10～20min后结束处理,得到成品腌腊鱼。本发明方法不但可以缩短腌制时间,提高腊鱼肌肉弹性,而且可以解决鱼体干燥后水分分布不均的问题,同时又能保持腊鱼特有的色泽和风味。(The invention relates to a method for preparing salted and cured fish by ultrasonic-assisted low-temperature heating. The method comprises the steps of immersing the preserved fish subjected to pretreatment, pickling and drying and vacuum packaging in an ultrasonic pool for ultrasonic treatment, adding a sample into the ultrasonic pool, starting a circulating thermostat heating circulating system, turning off a heater and starting an ultrasonic device for ultrasonic treatment when the water temperature rises to 40-50 ℃, controlling the ultrasonic power and frequency to be 500-700W and 18-20 kHz respectively, and finishing treatment after the ultrasonic time is 10-20 min to obtain the finished product of the preserved fish. The method of the invention not only can shorten the pickling time and improve the muscle elasticity of the preserved fish, but also can solve the problem of uneven water distribution after the fish body is dried, and simultaneously can keep the special color and flavor of the preserved fish.)

1. A method for preparing salted and cured fish by ultrasonic-assisted low-temperature heating, which comprises the following steps:

(1) pretreatment: killing fresh fish, removing head, tail, viscera and black membrane, cutting open along vertebra, cleaning, and draining;

(2) pickling: putting the drained fish meat into a pickling liquid for pickling for 0.5-3 h; the pickling liquid comprises the following components: 4-5 parts of potassium chloride, 4-5 parts of sodium chloride, 2-3 parts of salty peptide, 2-3 parts of mushroom powder, 2-3 parts of orange peel powder, 0.5-1 part of sage powder, 2-3 parts of sodium ascorbate, 1-2 parts of garlic powder, 0.2-1 part of monascus pigment and 10-70 parts of water;

(3) drying by a heat pump: after the pickling is finished, drying the pickled vegetables by a heat pump at the temperature of 10-20 ℃ and the air speed of 1-1.5 m/s for 40-60 hours continuously;

(4) packaging: vacuum packaging the dried fish;

(5) ultrasonic-assisted low-temperature heating treatment: soaking the salted and preserved fish in vacuum package in an ultrasonic pool for ultrasonic treatment, adding a sample into the ultrasonic pool, then starting a circulating thermostat heating circulating system, turning off a heater and starting an ultrasonic device for ultrasonic treatment when the water temperature rises to 40-50 ℃, controlling the ultrasonic power and frequency to be 500-700W and 18-20 kHz respectively, and finishing the treatment after the ultrasonic time is 10-20 min to obtain a finished product of salted and preserved fish.

2. The method according to claim 1, wherein the washing in step (1) is performed with a dilute brine having a mass concentration of 2 to 3%.

3. The method of claim 1, wherein the mass composition of the pickling solution in the step (2) is as follows: 4-5% of potassium chloride, 4-5% of sodium chloride, 2-3% of salty peptide, 2-3% of mushroom powder, 2-3% of orange peel powder, 0.5-1% of sage powder, 2-3% of sodium ascorbate, 1-2% of garlic powder, 0.2-1% of monascus pigment and the balance of water.

4. The method of claim 1, wherein the mass ratio of the fish meat to the pickling liquid in the step (2) is 1: 2-4.

5. The method according to claim 1, wherein the curing in the step (2) is performed under 20-40 KHz ultrasonic conditions for 1-2 h.

6. The method according to claim 1, wherein the vacuum packaging is performed in step (4) using a polyamide/polyethylene material having an oxygen permeability and a water permeability of 50cm, respectively ³/m ²24h and 2.6g/m ²/24h。

7. The method according to claim 1, wherein the step (5) of the ultrasound-assisted cryogenic heating treatment is performed in a dedicated temperature-controlled ultrasonic bath apparatus, the temperature-controlled ultrasonic bath apparatus mainly comprises an ultrasonic tank, a sample holder arranged in the ultrasonic tank, and a circulating water bath system which is communicated with the ultrasonic tank and consists of a circulating thermostat, a water tank, a plate heat exchanger and a refrigerating circulating bath, an ultrasonic generator and an amplifier are arranged at the bottom of the ultrasonic tank, the apparatus further comprises a process controller for controlling the circulating thermostat, the plate heat exchanger and the refrigerating circulating bath, the process controller is provided with a temperature sensing probe which extends into the ultrasonic tank for monitoring the temperature of the water, so as to realize automatic control of the process temperature, the ultrasonic treatment uses the water as a heating medium, the water level is controlled by the circulating thermostat, the temperature control system is arranged in the ultrasonic tank, and the water temperature is controlled by the plate heat exchanger and the refrigerating circulating bath, the flow rate of the circulating water is controlled to be 3-5L/min.

(I) technical field

The invention belongs to the technical field of aquatic product processing, and particularly relates to a method for preparing salted and cured fish through ultrasonic-assisted low-temperature heating.

(II) background of the invention

The preserved fish is a traditional preserved aquatic product with strong Chinese characteristics, and is an important component and a typical representative in the preserved aquatic product. The first people made salted and cured fish for long-term storage to prevent putrefaction. With the development of processing technology, the cured fish is developed into delicious food which is rich in nutrition, rich in flavor and convenient to store, and has a wide consumption market at home and abroad at present. However, the time for making the preserved fish is long, and epidemiological investigation shows that the incidence rate of hypertension of people who often eat the preserved aquatic products in coastal areas is high, which is closely related to the high sodium salt content in the preserved aquatic products. And the salted and cured fish is easy to soften and become sticky due to factors such as self fat oxidation, protein degradation and the like after being prepared, is not accepted by consumers and causes waste. In addition, the existing salted and preserved fish is mostly dried by hot air, and the flavor quality of the prepared salted and preserved fish is not good compared with the traditional sun-cured fish. Therefore, how to ensure the edible safety of the pickled aquatic products, reduce the content of sodium salt, shorten the process time, further improve the quality of the pickled preserved fish and prolong the shelf life is one of the problems which are urgently needed to be solved by the current processing industry of the pickled aquatic products.

At present, the salty peptide (guanamine taurine) does not contain sodium, has the taste which is the same as or stronger than the salty taste of sodium chloride, has a synergistic effect when being used with potassium chloride and sodium chloride, and can reduce the content of sodium salt; the mushroom powder is fungus food with high protein, low fat, polysaccharide, various amino acids and various vitamins, has a certain hydrogen peroxide removing effect, can inhibit oil oxidation, and has a certain freshness enhancing effect on products due to the fragrance component of mushroom essence in mushrooms; the orange peel powder, the sage powder and the sodium ascorbate also have good antioxidant effect, and can increase the flavor and improve the quality of the preserved fish; the garlic powder has good bacteriostatic effect; the monascus pigment is a natural pigment, and can make the preserved fish show good color, enhance flavor, inhibit growth of harmful microorganisms and prolong storage life.

In recent years, researches show that the low-temperature heating treatment can effectively balance the water distribution in the preserved fish and can solve the problems that the preserved fish becomes sticky and soft due to some internal factors such as low pH value, uneven water distribution and low salt concentration after processing treatment, but the heating treatment time is longer, and researches show that the heating time can be shortened by the aid of power ultrasonic (PuS) to assist the low-temperature heating. Ultrasound can increase the apparent thermal diffusivity to accelerate heat transfer, however, the higher the temperature, the lower the ultrasound intensification. However, the use of a temperature controlled ultrasonic bath avoids the increase in water temperature due to cavitation during the application of the ultrasonic waves. PuS can improve the conduction heat transfer and accelerate the uniform distribution speed of the moisture without increasing the temperature of the medium.

The invention with the application number of CN201610593044.9 discloses a preparation method of salted fish, which is prepared by the steps of removing internal organs and gills of fresh fish, cleaning, soaking, pickling, drying in sunlight, freezing and the like. The salted fish obtained by the processing method has high salt content, long preparation time, hard fish meat, poor mouthfeel and need of frozen storage.

The invention of application No. CN201410111801.5 discloses a method for pickling low-salt marine fish, which uses fresh fish or frozen fish as raw material, and the raw material is pretreated, pickled, desalted, packaged and stored to obtain pickled fish. The preparation method of the desalting solution has complicated process, complicated operation, long preparation time of salted fish, and requirement for freezing storage.

The salted and preserved fish prepared by power ultrasonic-assisted low-temperature heating has the advantages of balanced water distribution, moderate muscle hardness, low sodium salt content, excellent taste and capability of being stored at normal temperature. The method for making cured fish with these advantages is the development direction of the modern curing process.

Disclosure of the invention

In order to overcome the defects of the prior art and solve the problems of high sodium salt content, long pickling time, uneven water distribution of dried fish bodies and the like of the traditional pickled fish, the invention provides a method for preparing the pickled fish by power ultrasonic-assisted low-temperature heating.

The technical scheme adopted by the invention is as follows:

a method for preparing salted and cured fish by ultrasonic-assisted low-temperature heating, which comprises the following steps:

(1) pretreatment: killing fresh fish, removing head, tail, viscera and black membrane, cutting open along vertebra, cleaning, and draining;

(2) pickling: putting the drained fish meat into a pickling liquid for pickling for 0.5-3 h; the pickling liquid comprises the following components in parts by mass: 4-5 parts of potassium chloride, 4-5 parts of sodium chloride, 2-3 parts of salty peptide (guanamine taurine), 2-3 parts of mushroom powder, 2-3 parts of orange peel powder, 0.5-1 part of sage powder, 2-3 parts of sodium ascorbate, 1-2 parts of garlic powder, 0.2-1 part of monascus pigment and 10-70 parts of water;

(3) drying by a heat pump: after the pickling is finished, drying the pickled vegetables by a heat pump at the temperature of 10-20 ℃ and the air speed of 1-1.5 m/s for 40-60 hours continuously;

(4) packaging: vacuum packaging the dried fish;

(5) ultrasonic-assisted low-temperature heating treatment: soaking the salted and preserved fish in vacuum package in an ultrasonic pool for ultrasonic treatment, adding a sample into the ultrasonic pool, then starting a circulating thermostat heating circulating system, turning off a heater and starting an ultrasonic device for ultrasonic treatment when the water temperature rises to 40-50 ℃, controlling the ultrasonic power and frequency to be 500-700W and 18-20 kHz respectively, and finishing the treatment after the ultrasonic time is 10-20 min to obtain a finished product of salted and preserved fish.

The step (5) is carried out by adopting a special temperature control ultrasonic bath device, the temperature control ultrasonic bath device mainly comprises an ultrasonic pool, a sample frame arranged in the ultrasonic pool, and a circulating water bath system which is communicated with the ultrasonic pool and consists of a circulating thermostat, a water tank, a plate heat exchanger and a refrigeration circulating bath (cold ethylene glycol circulating bath (-2 ℃), wherein an ultrasonic generator and an amplifier are arranged at the bottom of the ultrasonic pool, the temperature control ultrasonic bath device also comprises a process controller used for controlling the circulating thermostat, the plate heat exchanger and the refrigeration circulating bath, the process controller is provided with a temperature sensing probe which extends into the ultrasonic pool and is used for monitoring the water temperature, the automatic control of the process temperature is realized (if heat is generated due to ultrasonic cavitation and the water temperature in the ⑦ ultrasonic bath exceeds a preset temperature, the ⑤ refrigeration circulating bath (set point is automatically opened by a ① process controller, the water temperature in the ⑤ refrigeration circulating bath is provided for the ultrasonic bath according to the temperature of the ultrasonic bath, the water temperature in the ⑦ ultrasonic bath is timely adjusted), the ultrasonic treatment takes water as a heating medium, the height is controlled by the water level of the circulating thermostat, the temperature control system is arranged in the ultrasonic pool, the plate heat exchanger, the water temperature control system is arranged in.

The special device has the following advantages: (1) automatic control: the device is provided with a process controller, and the temperature is sensed by a connected temperature sensor which is placed in the ultrasonic bath, so that the process is automatically controlled; (2) recycling of water: the ultrasonic bath, the refrigeration circulator, the circulating thermostat and the water tank are used for realizing the recycling of water. (3) And realizing accurate temperature control: under the action of the ultrasonic bath, heat is generated due to the ultrasonic cavitation, so that the temperature is raised, and the temperature of the ultrasonic bath is stable and the error is reduced by adjusting the refrigeration circulator. (4) Energy conservation and environmental protection: cold water and hot water are directly contacted by using the plate heat exchanger, so that the water temperature is in dynamic balance, and the energy consumption of the circulating thermostat and the refrigeration circulator is reduced.

The method of the invention not only can shorten the pickling time and improve the muscle elasticity of the preserved fish, but also can solve the problem of uneven water distribution after the fish body is dried, and simultaneously can keep the special color and flavor of the preserved fish.

The ultrasonic cavitation is utilized to have a certain erosion effect on the surface of the fish meat to form a plurality of permeation pore channels, so that the permeation of the pickling liquid into the fish meat is facilitated, the pickling time of the existing industrial production of pickled and cured fish is required to be 2-5 days, and the pickling time is shortened and the production efficiency is improved by only 0.5-3 hours.

And (2) cleaning with dilute saline water with the mass concentration of 2-3% in the step (1).

The mass composition of the pickling liquid in the step (2) is as follows: 4-5% of potassium chloride, 4-5% of sodium chloride, 2-3% of salty peptide, 2-3% of mushroom powder, 2-3% of orange peel powder, 0.5-1% of sage powder, 2-3% of sodium ascorbate, 1-2% of garlic powder, 0.2-1% of monascus pigment and the balance of water. The invention provides a safe, healthy and delicious pickling agent, wherein salty peptides have double effects of salty taste and delicate taste, can replace table salt to a certain extent to be used for cooking food, can be well absorbed and utilized by a human body, and are safer due to the effect of replacing nitrite with monascus pigment; the mushroom powder can inhibit the oxidation of grease, and the fragrant component in the mushroom is mushroom essence, which has a certain effect of enhancing the freshness of the product; the orange peel powder, the sage powder and the sodium ascorbate also have good antioxidant effect, and can increase the flavor and improve the quality of the preserved fish; the garlic powder has good bacteriostatic effect; the monascus pigment is a natural pigment, and can make the preserved fish show good color, enhance flavor, inhibit growth of harmful microorganisms and prolong storage life.

In the step (2), the mass ratio of the fish meat to the pickling liquid is 1: 2-4.

In the step (2), pickling is carried out under the ultrasonic condition of 20-40 KHz, and the pickling time is 1-2 h.

Vacuum packaging is carried out by using a polyamide/polyethylene material in the step (4), wherein the oxygen permeability and the water permeability of the polyamide/polyethylene material are respectively 50cm ³/m ²24h and 2.6g/m ²/24h。

The invention has the following beneficial effects:

(1) the use of the compound salt in the curing agent adopted by the invention is found to have a synergistic effect by measuring the content of sodium ions, the use of single sodium chloride is replaced, the content of sodium salt can be reduced by 60 percent, the curing agent accords with the healthy consumption appearance, and the ultrasonic treatment can accelerate the curing process.

(2) The invention adopts natural substances such as mushroom powder, orange peel powder, sage powder, sodium ascorbate, garlic powder and the like, so that the product has good color, aroma and taste.

(3) According to the invention, the dried salted and cured fish is subjected to power ultrasonic-assisted low-temperature heating treatment, so that the water distribution in the salted and cured fish can be effectively balanced, the problems of viscosity and softness of the salted and cured fish caused by some internal factors (such as low pH value, uneven water distribution and low salt concentration) after processing treatment can be solved, and the quality of the salted and cured fish is further improved.

(IV) description of the drawings

FIG. 1 shows a temperature-controlled ultrasonic bath apparatus of the present invention, ① process controller, ② circulating thermostat, ③ water tank, ④ plate heat exchanger, ⑤ refrigerating circulating bath, ⑥ sample holder, ⑦ ultrasonic cell, ⑧ ultrasonic transducer, ⑨ ultrasonic generator and amplifier.

FIG. 2 is a graph showing the change in the center temperature of the salted and cured fish under CV (conventional heat treatment) and PuS (power ultrasonic assistance) treatments. A: graph of change of central temperature of salted and preserved fish with time at 40 deg.C by CV (conventional heat treatment) and PuS (power ultrasonic assisted); b: graph of change of central temperature of salted and preserved fish under CV (conventional heat treatment) and PuS (power ultrasonic assisted) treatment at 45 ℃; c: graph of the temperature of the core of the cured fish with time at 50 ℃ under CV (conventional heat treatment) and PuS (power ultrasound assisted) treatment.

(V) detailed description of the preferred embodiments

The invention will be further described with reference to specific examples, but the scope of the invention is not limited thereto: