Fish meat directional mass transfer processing method based on magnetic field-assisted microwave mixed ripening technology

Abstract

The invention discloses a fish meat directional mass transfer processing method based on a magnetic field-assisted microwave mixed ripening technology, and belongs to the technical field of food processing, and the method comprises the following steps: salting fish meat, washing, pre-ripening by using an alternating magnetic field, then wrapping the pre-ripening fish meat by using a ripening treatment liquid, and drying to obtain the fish meat. And then, microwave-assisted directional mass transfer ripening is adopted to obtain the ripened fish meat. The whole ripening process is short in time consumption, and the ripening astroconger eel has a proper air-dried layer, has a plant fresh scent, a light fermentation flavor, a cheese flavor and a sweet flavor, almost has no fishy smell of fish meat, is extremely soft in meat quality, relatively good in resilience, obvious in coking layer after frying and baking, rich in flavor, obvious in scorch aroma and fresh scent, fine and juicy in meat quality during chewing, and outstanding in delicate flavor. Moreover, the method provided by the invention is simple, raw materials are easy to obtain, and popularization and application are facilitated.

Description

Technical Field

[0001] The present invention belongs to the technical field of food processing, and particularly relates to a method for directional mass transfer processing of fish meat based on a magnetic field-assisted microwave hybrid aging technology. Background Art

[0002] The purpose of aging is to change the state of food materials over time, making their texture softer and flavor more intense, so as to reach the best edible state. The aging technology originated from the need for food preservation and has since spawned countless aging technologies and products. Broadly speaking, aging can be subdivided into aging methods such as drying, salting, smoking, and fermentation. Narrowly speaking, aging can be subdivided into dry aging, wet aging, salt aging, etc. In addition, butter aging, beeswax aging, wine aging, spice aging, sawdust aging, oil aging, and hybrid aging have also emerged. Although conventional aging technologies (dry aging, wet aging) can significantly improve the flavor and texture of meat, they also have disadvantages such as long aging time, flavor loss, uncontrollable texture, water loss, raw material loss, risk of microbial contamination, high cost, and difficulty in ensuring flavor consistency, and there are problems in terms of efficiency, mass transfer, and quality control.

[0003] Traditional aging technologies such as dry aging are based on evaporating the moisture of raw materials to achieve flavor concentration. After aging, the meat becomes more tender and produces unique nutty and cheesy aromas. However, the hard shell formed on the surface of the meat will reduce the yield, and the aging time required is long; wet aging generally uses vacuum sealing and low-temperature storage to retain moisture, and the aging time is short, but the improvement in flavor and tenderness is limited; salt aging can enhance the umami taste of meat products and extend the shelf life, but it may make the texture of the meat harden and cover up the original taste of the food materials; butter aging uses butter to seal and wrap the meat products to isolate the air, which can appropriately add dairy flavors and has a similar effect to wet aging in terms of moisture retention and tenderness improvement, but its cost is high, the applicability is limited, and the flavor components in butter are difficult to penetrate into the meat products well. In addition, during the grilling process of meat products (especially beef and fish with high fat content), a charred layer or a crispy layer is pursued, and dry aging is more conducive to the formation of the charred layer. Aiming at the defects in the above traditional aging methods, the application of hybrid aging technology in the aging processing of high-end meat products has high potential. Common hybrid aging technologies include the combination of wet aging and spice aging, and the combination of dry aging and wine aging. For the processing requirements of high-end aged meat products, innovation can be carried out on the aging objects.

[0004] The raw materials used in traditional aging processes mainly include beef, pork, mutton, poultry, and fish (such as salmon and tuna), etc. Among them, fish with high fat content is more suitable for aging. After aging, the flavor and texture are significantly improved. Taking Conger myriaster as a development case, it is an important economic fish, widely caught and farmed, rich in protein and fat, with delicious meat, delicate texture, and unique flavor. It is often used in Japanese cuisine, such as making sashimi, grilled eel, and stewed soup, etc., and has high potential for aging processing.

[0005] Therefore, how to provide an aging process to achieve effects such as improving aging efficiency, enhancing flavor, improving texture, and reducing water loss, as well as developing new aquatic processed products such as aged Conger myriaster is a technical problem that needs to be urgently solved by those skilled in the art. Summary of the Invention

[0006] To solve the above technical problems, the present invention proposes a method for directional mass transfer processing of fish meat based on magnetic field-assisted microwave hybrid aging technology.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A method for directional mass transfer processing of fish meat based on magnetic field-assisted microwave hybrid aging technology, comprising the following steps:

[0009] The fish meat is salted and then washed, pre-aged using an alternating magnetic field, and then the pre-aged fish meat is wrapped with an aging treatment liquid, and then microwave-assisted directional mass transfer aging is adopted to obtain aged fish meat.

[0010] Beneficial effects: The present invention adopts mild salting processing and alternating magnetic field treatment for fish meat segments, which can form an air-dried layer and further dissolve myofibrillar proteins and tenderize the meat quality. After removing the muscle slurry and fish meat salt with running water, the fish meat is further processed using alternating magnetic field technology to further open the internal mass transfer channels of the fish meat and enhance the activity of calpain and cathepsin inherent in the fish meat, achieving meat tenderization and flavor enhancement, and strengthening the formation of the air-dried layer. In addition, after evenly wrapping the aging treatment liquid around the fish meat segments, the obtained fish meat blocks are further processed using intermittent microwave technology to promote the directional mass transfer of moisture and flavor, further tenderize the meat quality and shorten the aging time, and the obtained shell-covered fish meat is stored at 4°C in the refrigerator. The overall aging process in the present invention takes a short time, and the obtained aged fish meat has a moderate air-dried layer, with a plant fragrance, a mild fermentation flavor, a cheese flavor, and a sweet fragrance, almost no fishy smell, extremely soft meat quality, good resilience, an obvious coking layer after frying and grilling, rich flavor, obvious caramel flavor and fragrance, delicate and juicy meat when chewing, and prominent umami.

[0011] Preferably, the raw material of the fish meat includes one or more of Conger myriaster, rainbow trout, tilapia, eel, and puffer fish.

[0012] Preferably, the salting is dry-salt salting or wet-salt salting.

[0013] Among them, for those pursuing the charred layer and rich meat aroma of aged meat products, dry-salt salting can be adopted, and for meats pursuing tenderness and juiciness, wet-salt salting can be adopted.

[0014] Preferably, the dry-salt salting is carried out using salt powder after ultrafine grinding, and the mass ratio of the fish meat to the salt powder is 20:1.

[0015] Beneficial effects: Different from conventional salted foods, in the present invention, due to the osmotic effect of salt on the surface of the fish meat and the promotion of the dissolution of salt-soluble proteins on the surface of the fish meat, coupled with the extremely strong water absorption of the ultrafine salt powder, a layer of muscle serous fluid layer is quickly formed, and a wrapping layer is formed with the salt that is not completely dissolved. Drain the water in the container and spread the fish meat flat to dry in the shade. The purpose of this step is to promote the precipitation of salt-soluble proteins on the surface of the fish meat and the air-dried layer formed due to rapid water loss. Salt dehydration will reduce the gaps between muscle fibers on the surface of the fish meat, making the surface denser. At the same time, salt can also play a role in preservation. Short-term salting also helps dissolve some myofibrillar proteins of the fish meat, increasing the tenderness of the fish meat.

[0016] Preferably, the wet-salt salting includes the following steps:

[0017] Immerse the fish meat in a 3% salt water, then perform vacuum and pulse circulation treatment, and then let it stand still stably.

[0018] More preferably, the wet-salt salting includes the following steps:

[0019] Use an excessive amount of 3% concentrated salt water, requiring the conger eel meat to be submerged. Adopt pulsed vacuum-assisted osmosis. Start the vacuum equipment, reduce the pressure in the container to 0.08 MPa, and keep it for 5 minutes to discharge the air inside the fish meat. After the vacuum stage ends, apply a positive pressure to 0.2 MPa appropriately and keep it for 5 minutes. Repeat the above vacuum and pulse circulation 3 times to promote the penetration of salt and the migration of flavor substances, and at the same time, it can improve the thermal stability of proteins. Then let it stand still stably in the salt water for 0.5 h to stabilize the salinity.

[0020] Beneficial effects: The mild salting process in the present invention is beneficial to increasing the dissolution of salt-soluble proteins, enabling the juice to be better adsorbed in the myosin fibers, promoting the release of flavor substances, and tenderizing the meat well. The salting process conforms to Fick's diffusion law. Mild salting supplemented with pulsed vacuum treatment helps promote directional mass transfer and meat quality improvement. At the same time, it is beneficial to form a water-blocking layer, increase the water-holding capacity of the meat product, and can better endow the fish meat with a crispy layer after cooking.

[0021] Preferably, the pre-cooking is to turn on the alternating magnetic field for 0.5 h, stop for 3 h, and repeat three times.

[0022] Preferably, the temperature of the pre-aging is 4°C and the humidity is 75 - 85%; the frequency of the alternating magnetic field is 50 Hz and the intensity is 0.2 T.

[0023] Beneficial effects: The present invention applies an alternating magnetic field to the aging process. Through the action of a periodically changing magnetic field, the activity of enzymes in meat products can be accelerated, promoting the decomposition of proteins and fats, and presumably shortening the aging time. The change in the magnetic field can also induce the movement of water and ions inside the meat products, accelerating the formation and penetration of flavor substances. The alternating magnetic field can change the structure of muscle fibers, making them softer and improving the tenderness of meat products. By controlling the magnetic field frequency and intensity, the texture of meat products can be precisely adjusted to avoid over-softening or hardening. During this pre-aging process, natural enzymes in the meat decompose proteins and fats. For example, the magnetic field can promote the decomposition of proteins by calpain and cathepsin, contributing to the production of amino acids and flavor substances. At the same time, the surface moisture of the fish evaporates moderately, playing a role in concentrating the flavor, and the mass transfer channels inside the fish are further opened under the action of the magnetic field.

[0024] Preferably, the aging treatment liquid is obtained by fermenting noni fruit and then mixing it with old fragrant yellow or butter.

[0025] More preferably, the aging treatment liquid includes noni fruit old fragrant yellow treatment liquid or noni fruit butter treatment liquid.

[0026] Beneficial effects: The noni fruit fermentation broth has excellent nutritional value and processing characteristics. Its raw material, noni fruit, is a tropical fruit native to Southeast Asia and Australia. In recent years, it has received extensive attention worldwide due to its unique nutritional value and health effects. Its fermentation broth contains various bioactive components such as flavonoids, polyphenolic compounds, and organic acids. The unique fermentation flavor can give the aged meat products with butter a unique flavor experience. Old fragrant yellow is a traditional Chinese medicine mainly derived from the dried ripe fruits of Rutaceae plants (such as bergamot). It has the effects of regulating qi, resolving phlegm, and strengthening the stomach. It is particularly famous in the Chaoshan area and is often made into preserved fruits or pickled foods. It has important cultural value and storage value. The longer the storage period, the higher the efficacy and economic value. The old fragrant yellow made from bergamot has a unique aroma, with the fresh fragrance of citrus plants, and at the same time combines spicy and sweet fragrances. Its taste is soft and delicate, sweet and sour, and has an extremely long storage time, making it feasible as an aging sealing wall material.

[0027] In the Noni fruit butter treatment solution, the Noni fruit fermentation broth will interact with the components of the butter, changing the fat crystallization behavior. During the solidification process, the high internal phase emulsion may form a denser fat crystal network, thereby increasing the melting point of the butter and enhancing the stability of the butter as a wall material. After the fish is coated with the Noni fruit fermentation broth mixed with the butter treatment solution layer, the conventional butter aging process is directly carried out. The microorganisms inside the introduced Noni fruit fermentation broth can accelerate the aging, increasing the buttery flavor and creaminess of the butter. The mass transfer channels inside the fish also contribute to the migration of moisture and the mass transfer of flavor substances, which is beneficial to avoiding the defect that traditional butter-aged meat products lack the butter flavor. The butter used in traditional butter aging has more technological innovation value. In this invention, the butter is combined with the Noni fruit fermentation broth to prepare a high internal phase emulsion as the wall material for meat products, which can improve the flavor, texture and nutritional value of meat products, and at the same time extend the shelf life.

[0028] More preferably, the preparation method of the Noni fruit Laoxianghuang treatment solution comprises the following steps:

[0029] (1) Preparation of Noni fruit fermentation broth: Cut the Noni fruit pulp into pieces and homogenize it, then mix it with water and sucrose and seal it for fermentation for 1 week to obtain the Noni fruit fermentation broth; among them, the Noni fruit pulp has indigenous bacteria, and the main strain is lactic acid bacteria. Therefore, in the preparation process of the Noni fruit fermentation broth in this invention, no foreign strains need to be added, and the Noni fruit can be naturally fermented to obtain the Noni fruit fermentation broth rich in lactic acid bacteria.

[0030] (2) Cut the Laoxianghuang into pieces and homogenize it, mix it with the Noni fruit fermentation broth and coconut oil, stir and heat it to 60 - 70 °C, then add a thickening agent and an emulsifier, stir evenly and filter it to obtain the Noni fruit Laoxianghuang treatment solution.

[0031] More preferably, in step (1), the mass ratio of the fruit pulp to water is 1:1, and the sucrose is 5% of the mass of the fruit pulp.

[0032] More preferably, in step (2), the thickening agent is a carrageenan solution with a concentration of 0.25 g / mL;

[0033] The emulsifier is lecithin.

[0034] Beneficial effects: The thickening agent and the emulsifier are used to stably improve the rheological properties of Laoxianghuang and make up for the difference in rheological stability between it and the butter with a lower freezing point.

[0035] More preferably, the addition ratio of the Laoxianghuang, Noni fruit fermentation broth, coconut oil, thickening agent and emulsifier is 500 g:50 mL:30 mL:20 mL:5 g.

[0036] More preferably, the sign of being stirred evenly in step (2) is to obtain a shiny, black and viscous paste-like fluid that does not stick to the spoon.

[0037] More preferably, the preparation method of the noni fruit butter treatment liquid comprises the following steps:

[0038] (1) Preparation of noni fruit fermentation liquid: Cut the noni fruit pulp into pieces, homogenize it, then mix it with water and sucrose, seal and ferment for 1 week to obtain the noni fruit fermentation liquid;

[0039] (2) Melt the butter, add the noni fruit fermentation liquid obtained in step (1), mix evenly, and then add an emulsifier for homogenization to obtain the noni fruit butter treatment liquid.

[0040] More preferably, the mass ratio of the butter to the noni fruit fermentation liquid is 4:1.

[0041] The rotation speed of the homogenization is 10,000 rpm and the time is 3 min.

[0042] The emulsifier is lecithin.

[0043] More preferably, the aged treatment liquid can be coated with old fragrant yellow in two ways: manual coating and soaking. When the treatment amount is small, the manual coating method is adopted. Place the fish fillets on a rack with a tray, use a clean spatula or spoon, take an appropriate amount of old fragrant yellow that has been left standing at room temperature, start from one end of the fish fillet, and evenly apply it to the other end to ensure complete coverage of the surface. Repeat this operation four times to ensure the formation of a relatively dense and uniform-thickness old fragrant yellow layer. In large-scale commercial production, the soaking method can be adopted. Immerse the fish fillets completely in the old fragrant yellow, take them out after 15 seconds, and repeat this operation 4 times.

[0044] Preferably, the power of the microwave-assisted directional mass transfer aging is 300 W, and the intermittent start-stop method of working for 15 s and stopping for 15 s is adopted, and the cycle is 5 times.

[0045] Preferably, during the microwave-assisted directional mass transfer aging process, the internal temperature of the fish < 45 °C.

[0046] Beneficial effects: The microwave used in the microwave technology is a high-frequency electromagnetic wave, which can penetrate food and make the internal polar molecules (such as water molecules) vibrate rapidly, thereby generating heat. The application of microwave technology in aging processing has significant feasibility, and there have been research reports on microwave-assisted aging processing. It can realize heat generation from the inside out, can improve mass transfer, increase the aging efficiency and improve the tenderness of fish. This technology has strong controllability, and the aging process can be precisely controlled by adjusting the microwave power, frequency and time. However, it is difficult to control the direction of water migration in conventional microwave treatment, and the penetration depth of the magnetic field alone is insufficient. Therefore, the present invention adopts the combined technology of magnetic field and microwave, magnetic field pretreatment for aging, and microwave-assisted directional mass transfer aging. The microwave-assisted aging treatment liquid is directionally aged, which helps to accelerate the interaction between the wall material content in the aging treatment liquid and the starry flounder meat, and improve the flavor and texture.

[0047] Compared with the prior art, the present invention has the following advantages and technical effects:

[0048] The present invention uses magnetic field and microwave technologies as pretreatment and process - assisting technologies, enhancing the aging efficiency and controllability; adopts a hybrid aging technology, drawing on the advantages of technologies such as salt - aging, wet - aging, dry - aging, and butter - aging, greatly improving the texture, flavor, and taste of the aged products. At the same time, the present invention innovatively applies the traditional Chinese medicine and food homology of "Laoxianghuang" as the coating wall material for imitation butter - aging. The unique cultural heritage and economic value of "Laoxianghuang" can effectively echo the attributes of the aged meat products, amplifying the cultural characteristics. The present invention adds Noni fruit fermentation broth to the aging wall material, and the cellulose and polysaccharides therein can play a certain thickening and emulsifying role, endowing the aging - required wall material with good physical and chemical properties. Moreover, the abundant lactic acid bacteria in the fermentation broth contribute to the decomposition of proteins and fats, accelerating aging, tenderizing fish meat, enhancing flavor, and the lactic acid fermentation process can reduce the pH value of fish meat and inhibit the growth of harmful microorganisms. Finally, the method provided by the present invention is simple, the raw materials are easily available, and it is convenient for popularization and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The drawings forming a part of this application are used to provide a further understanding of this application. The schematic embodiments and descriptions thereof of this application are used to explain this application and do not constitute an improper limitation to this application. In the drawings:

[0050] Figure 1 It is a radar chart of the sensory evaluation of the aged Conger myriaster meat obtained in Example 1 and Comparative Examples 1 - 2;

[0051] Figure 2 It is a result chart of the weight loss rate during the aging process of the aged Conger myriaster meat obtained in Example 1 and Comparative Examples 1 - 2;

[0052] Figure 3 It is an image of the cross - section of muscle fibers at 100× taken under a microscope after the aged Conger myriaster meat obtained in Example 1 and Comparative Examples 1 - 2 is stained with HE;

[0053] Among them, A is Comparative Example 1, B is Comparative Example 2, and C is Example 1;

[0054] Figure 4 It is an SEM result chart of the aged Conger myriaster meat obtained in Example 1 and Comparative Example 1 at a magnification of 300×;

[0055] Figure 5 It is a diagram of the directional mass transfer mechanism during the aging process of Example 1. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0056] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0057] In order to make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0058] Unless otherwise specified, the raw materials in the embodiments of the present invention are all obtained through commercial channels.

[0059] Unless otherwise specified, the room temperature or normal temperature in the embodiments of the present invention refers to 25 ± 3°C.

[0060] Example 1

[0061] A method for directional mass transfer processing of Conger myriaster meat based on magnetic field-assisted microwave hybrid aging technology, comprising the following steps:

[0062] (1) Raw material trimming: Take fresh Conger myriaster (1.5 - 2 catties per fish, preferably Conger myriaster with accumulated fat during the overwintering period), remove the head, tail, and skin, cut it open, remove the internal organs and flatten it, wash it with running water, and cut it into sections every 30 cm.

[0063] (2) Dry salt salting: Use ultrafinely ground salt powder, and quickly coat the fish meat segments with salt according to the ratio of fish meat to salt of 20:1 (w / w). Then, in a sealed plastic container, stack the fish in a form of one layer of fish and one layer of salt, with the original fish skin side facing down, and place it at 4°C for 1 h. Then, quickly wash it with running water to remove the excess saltiness, drain it, and perform subsequent processing.

[0064] (3) Alternating magnetic field pretreatment: Place an alternating magnetic field generator in an adjustable constant temperature and humidity chamber, then stack the fish meat after dry salt salting obtained in step (2) on a bracket, and then place it in the constant temperature and humidity chamber for aging. Among them, the aging temperature is 4°C, the humidity is 75 - 85%, the magnetic field frequency is 50 Hz, and the magnetic field intensity is 0.2 T. Intermittently apply the magnetic field to the fish meat, turn it on for 0.5 h and stop for 3 h, and repeat three times. Obtain pre-aged Conger myriaster meat.

[0065] (4) Preparation of Noni Fermented Liquid: Select fresh Noni fruit, wash and cut it into pieces, use a food processor to homogenize the pulp, then put the fruit puree into a pre-sterilized fermentation tank, add purified water at a mass ratio of 1:1, and add 5% sucrose by weight of Noni fruit as a fermentation carbon source. Then seal the container and place it in a cool and dry place for fermentation for 1 week. During this period, observe the fermentation status every day and shake the container gently. Normal fermented liquid should have a moderate sour taste and bubble generation. After fermentation, filter the fermented liquid with 2 layers of 80-mesh gauze, let the filtrate stand and filter it again with 120-mesh gauze to obtain Noni Fermented Liquid, which is stored in a refrigerator (4°C).

[0066] (5) Preparation of the old fragrant yellow processing liquid of Noni fruit: 500g of three-year-old fragrant yellow was cut into small pieces and homogenized in a food processor for 2 minutes, during which the "black oil" in the storage process of the old fragrant yellow was appropriately added to increase the flavor and color. After sufficient homogenization, the mixture was transferred to a pot, 50mL of the Noni fruit fermentation liquid obtained in step (4) was added, and 30mL of coconut oil was added to increase the oiliness and unique flavor. The mixture was stirred continuously, and after the temperature was raised to 60°C to 70°C, 5g of carrageenan pre-melted in 20mL of water was added as a thickener, and 5g of lecithin was added as an emulsifier. The mixture was stirred thoroughly until a glossy black viscous paste-like fluid was obtained, which was preferably not sticky to a spoon, and then sieved through a 20-mesh coarse sieve to make its texture more delicate, thereby obtaining the old fragrant yellow processing liquid of Noni fruit.

[0067] (6) Ripening treatment: Wipe the surface moisture of the pre-ripened conger eel meat obtained in step (3), and then use the Noni fruit old fragrant yellow processing liquid obtained in step (5) to wrap the pre-ripened conger eel meat to form a covering shell about 3 to 6 cm thick, seal it with plastic wrap, and then place it in a microwave device after refrigeration and shaping. Under low power conditions of 300 W, microwave treatment is carried out with an intermittent start-stop strategy of working 15s / stopping 15s, and the number of cycles is 5 times. At the same time, a central thermometer is inserted to ensure that the internal temperature of the fish meat does not exceed 45°C to avoid protein denaturation and hardening of the meat. After the microwave-assisted aging is completed, the old fragrant yellow croaker meat segment is placed in a refrigerated environment at 4°C and continues to mature for 6 hours, that is, the aging treatment is completed to obtain mature conger eel meat.

[0068] (7) The mature conger eel meat is packaged in a vacuum bag, the air is removed, the bag is sealed, and the bag is refrigerated for storage. The old yellow layer needs to be removed before consumption, and the adhesion between the fish meat and the old yellow layer can be appropriately cut off before cooking.

[0069] Example 2

[0070] A method for processing conger eel meat by directional mass transfer based on magnetic field-assisted microwave mixing and ripening technology, which is different from Example 1 only in that the noni fruit old fragrant yellow processing liquid is replaced with the noni fruit fermentation liquid mixed with butter processing liquid, and the preparation method of the noni fruit fermentation liquid mixed with butter processing liquid comprises the following steps:

[0071] Cut the butter into small pieces and melt it in a pot at low temperature. Put the melted butter into a container and add the Noni fruit fermentation broth, with a ratio of 4:1 (butter:fermentation broth). Use a stirrer to stir at low speed to initially mix evenly. Transfer the mixture to a homogenizer. During homogenization, add 1% lecithin to increase the emulsion stability and other emulsifying properties. Set the homogenizer speed to 10,000 rpm and homogenize for 3 minutes to obtain the Noni fruit fermentation broth mixed butter treatment liquid. The remaining process steps and parameters are the same as those in Example 1.

[0072] Example 3

[0073] A method for directional mass transfer processing of Conger myriaster meat based on magnetic field-assisted microwave hybrid aging technology, which is different from Example 2 only in that: replace the Noni fruit fermentation broth mixed butter treatment liquid with butter, without adding the Noni fruit fermentation broth, which is a traditional butter aging process, and add spices such as rosemary and vanilla to enhance the flavor of the butter. The remaining process steps and parameters are the same as those in Example 1.

[0074] Comparative Example 1

[0075] A method for directional mass transfer processing of fish meat, which is different from Example 1 only in that: steps (3)-(6) are not included, and the Conger myriaster meat obtained in step (2) is directly placed in a constant temperature and humidity box at 4°C and 75% humidity for dry aging for 18 h. The remaining process steps and parameters are the same as those in Example 1.

[0076] Comparative Example 2

[0077] A method for directional mass transfer processing of fish meat includes the following steps:

[0078] (1)-(3) are the same as in Example 1;

[0079] (4) Aging treatment: Gently wipe the surface moisture of the pre-aged Conger myriaster meat obtained in step (3), place it in a microwave device after cold storage and shaping, and perform microwave treatment under the low-power condition of 300 W with an intermittent start-stop strategy of working for 15 s / stopping for 15 s. The number of cycles is 5 times. At the same time, insert a central thermometer for sampling to ensure that the internal temperature of the fish meat does not exceed 45°C to avoid protein denaturation and hardening of the meat quality. After the microwave-assisted aging is completed, place the fish meat segments in a refrigerated environment at 4°C and continue to age for 6 h to complete the aging treatment and obtain the aged Conger myriaster meat.

[0080] (7) is the same as in Example 1.

[0081] Technical effects:

[0082] 1. Sensory evaluation form

[0083] The conger eel meat obtained in step (10) of Example 1 was labeled as Group 1, the conger eel meat obtained in Comparative Example 1 was labeled as Group 2, and the conger eel meat obtained in Comparative Example 2 was labeled as Group 3. Sensory evaluation was carried out on the above five groups of aged fish meat. Sensory evaluation of the product was carried out from five aspects: color, odor, texture, tissue state, and acceptability. The evaluation of each dimension was on a 20-point scale, and the evaluation indexes are shown in Table 1.

[0084] Table 1 Sensory evaluation indexes of conger eel meat with different aging methods

[0085]

[0086]

[0087] The sensory evaluation radar chart of the aged conger eel meat obtained in Example 1 and Comparative Examples 1-2 is as Figure 1 shown. It can be seen from Figure 1 that all indexes of the aged conger eel meat obtained in Example 1 are relatively prominent. The scores of its odor and acceptability are much higher than those of Comparative Examples 1 and 2. This may be related to the rich plant fragrance, sour and sweet taste, fermentation flavor and even cheese flavor and other sensory excellent flavor characteristics brought by the aging with old fragrant yellow. While greatly improving the aging efficiency in Example 1, the specific microbial environment such as lactic acid bacteria brought by old fragrant yellow and noni fruit fermentation broth will be much faster than the fermentation efficiency of microorganisms proliferated from the air and the fish meat surface in traditional dry aging. And pulse vacuum-assisted salting, magnetic field pretreatment, microwave-assisted aging, etc. have realized the directional mass transfer of meat products, greatly promoting the internal water migration of fish meat, the decomposition of proteins and fats, and the exudation and infiltration of flavor substances. By comparing Example 1 and Comparative Example 2, it can be concluded that without old fragrant yellow as the wall material, directly using microwave-assisted aging may face the problems of controlling the texture and color of fish meat. And as the wall material, the rich fat-soluble components of old fragrant yellow greatly improve the gloss of the fish meat surface and play a good barrier protection role on the fish meat surface tissue.

[0088] 2. Weight loss rate:

[0089] The weight loss rate during the aging process was obtained by comparing the weight loss of conger eel meat before and after aging, and measured in parallel 3 times. The formula is as follows:

[0090]

[0091] The weight loss rates of Example 1 and Comparative Examples 1-2 during the fish meat aging process are as Figure 2 shown. It can be seen from Figure 2It can be seen that compared with the two comparative examples, Example 1 effectively reduces the weight loss during aging. During dry aging, the fish meat is directly exposed to the environment, and a large amount of moisture is lost through evaporation and surface air drying. As a natural fermentation product, laoxianghuang has certain moisture retention and sealing properties, which can effectively reduce the evaporation of moisture on the surface of the fish meat, thereby reducing the weight loss rate. In addition, traditional dry aging mainly relies on the action of microorganisms and enzymes in the environment, and this process may lead to further loss of internal moisture and nutrients in the fish meat. However, the beneficial microorganisms (such as lactic acid bacteria) in the laoxianghuang aging of the present invention produce metabolites during the fermentation process to form a protective layer, reducing the loss of internal moisture in the fish meat and promoting the formation of flavor at the same time.

[0092] 3. Microstructure:

[0093] HE staining: Cut the aged Conger myriaster meat into small pieces with dimensions of 1 cm × 1 cm × 1 cm, soak in paraformaldehyde fixative at 4°C for 8 h, dehydrate in a gradient manner in 75% to 100% ethanol, then embed the sample in paraffin, stain the cross-section with a thickness of about 4 μm with hematoxylin and eosin solution, and take images using an optical microscope.

[0094] Scanning electron microscope (SEM): Cut the aged Conger myriaster meat into sheet samples with dimensions of 4.0 mm × 4.0 mm × 1 mm, fix in 0.1 mol / L phosphate buffer solution (pH 7.2) containing 2.5% glutaraldehyde at 4°C for 24 h, then rinse with 0.1 mol / L phosphate buffer solution (pH 7.2), and then perform gradient elution with 30% to 100% ethanol solution. After dehydration, the sample is freeze-dried, fixed, and sputter-coated with gold, and then observed using SEM.

[0095] Figure 3 are images of the cross-section of muscle fibers at 100× taken under a microscope after HE staining of the aged Conger myriaster meat obtained in Example 1 and Comparative Examples 1-2. After staining, the muscle fibers appear red, the white irregular areas between the muscle fibers are the gaps formed between the dehydrated muscle fibers, and the white reticular structure corresponds to the endomysium (cell gap). From Figure 3It can be seen that, compared with Comparative Examples 1 and 2, the white irregular areas in Example 1 are very obvious, and the gaps between muscle fibers are larger, indicating more protein decomposition, such as protein salting out and enzymatic degradation of muscle structure components, which increases the gaps between muscle fibers. This helps water migration and improves the water-holding capacity inside the fish meat. With protein decomposition and water migration, some muscle fibers will swell, increasing the fiber width. The comparison of the three groups of pictures shows that magnetic field and microwave treatment help the physical destruction of the myofibril structure and the creation of microchannels. The addition of lao xiang huang as a ripening wall material provides a hydrophobic layer shell for the fish meat and increases the microbial fermentation effect during the ripening process, increasing the decomposition of proteins and fats and enlarging the gaps between muscle fibers.

[0096] Figure 4 Figure 4 shows the SEM results of the ripened Conger myriaster meat of Example 1 and Comparative Example 1 at a magnification of 300×. Figure 4 It can be seen that after magnetic field pretreatment and microwave-assisted lao xiang huang ripening, the fiber pores on the cross-section of the fish meat are more and more obvious, which may help to open the mass transfer channels, that is, it is beneficial to the outward migration of polar molecules such as water, making the water distribution in the fish meat more uniform. And both magnetic field and microwave treatment can improve cell permeability, which helps to improve the ripening efficiency and the transfer of flavor substances.

[0097] 4. Bidirectional mass transfer mechanism:

[0098] The overall processing process in the present invention involves a large number of mass transfer processes, all of which follow Fick's diffusion law, and substances diffuse driven by the concentration gradient. With the help of the magnetic field-assisted microwave mixing ripening technology, the directional mass transfer of water, salt, heat, fat-soluble components, nutrients and flavor substances is better realized. The directional mass transfer mechanism during the ripening process is as Figure 5As shown. For example, during the process of pulsed vacuum treatment assisted by mild salting treatment, salt gradually penetrates from the surface of the fish meat into the interior of the fish meat, and flavor substances (such as amino acids, nucleotides, lipids, etc.) diffuse from the interior of the fish meat to the low-concentration area (i.e., the surface of the fish meat). The alternating magnetic field pretreatment also promotes directional mass transfer, enhances the movement of polar molecules in the fish meat and the cell membrane permeability, and through the setting of specific frequencies and intensities, guides the molecules to move in a specific direction. During the microwave-assisted aging process of Laoxianghuang, the present invention uses a Laoxianghuang treatment solution that is a homogeneous mixture of Noni fruit fermentation broth and presents a viscous paste as the wall material. Thanks to the quality improvement of the aging process by microwave technology, the present invention proposes a two-way mass transfer and directional mass transfer mechanism during the aging mass transfer process. Among them, the two-way mass transfer process is as follows: Microwaves selectively heat water molecules, and the temperature gradient formed from the inside out forms a temperature gradient inside the fish meat. The wall material layer rich in fat-soluble flavor substances and the hydrophilic protein layer inside the fish meat form a chemical potential difference, generating a concentration gradient that drives the transfer of flavor substances. Water migration: The water in the myofibril gaps diffuses along the temperature gradient, and microwave pulses help to improve the cell membrane permeability characteristics; Flavor infiltration: The fat-soluble flavor substances in Laoxianghuang gradually migrate into the interior of the fish meat under the drive of the concentration gradient. The directional mass transfer process is as follows: Under the drive of the microwave field, some polar components form a molecular-level "transport channel", and the microwave non-thermal effect activates the cell membrane ion channels, which can promote the active transport of flavor components. The temperature gradient, the thermodynamic property difference between the fish meat and Laoxianghuang, and the microwave intermittent heating help to form an interface layer that maintains a semi-solid state, that is, the Laoxianghuang close to the fish meat may form a network structure, allowing the selective passage of small molecule nutrients and flavor substances in the wall material, while blocking the loss of large molecule proteins in the fish meat. The temperature difference with the Noni fruit Laoxianghuang treatment solution helps to concentrate the flavor substances inside the fish meat, and the osmotic pressure formed by the concentration gradient directionally guides the one-way penetration of the flavor components of Laoxianghuang and Noni fruit fermentation broth in the Noni fruit Laoxianghuang treatment solution. Subsequently, with the help of mass transfer kinetics and thermodynamics research, the quantitative monitoring of the aging process can be further realized, and the best aging state can be controlled by deeply exploring the product quality parameters.

[0099] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed in the present application should be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A fish meat directional mass transfer processing method based on magnetic field assisted microwave mixing cooking technology, characterized in that: The following steps are involved: The fish meat is salted and then washed, pre-ripened using an alternating magnetic field, and then wrapped with a ripening treatment liquid, followed by microwave-assisted directional mass transfer ripening to obtain cooked fish meat.

2. The method for directional mass transfer processing of fish meat based on magnetic field-assisted microwave mixing and cooking technology according to claim 1, characterized in that: The raw materials of the fish meat include one or more of conger eel, rainbow trout, tilapia, eel and puffer fish.

3. The method for directional mass transfer processing of fish meat based on magnetic field-assisted microwave mixing and ripening technology according to claim 1, characterized in that: The salting is dry salt salting or wet salt salting.

4. The method for directional mass transfer processing of fish meat based on magnetic field-assisted microwave mixing and cooking technology according to claim 3 is characterized in that: The dry salting is performed by using ultrafinely crushed salt powder, and the mass ratio of the fish meat to the salt powder is 20:

1.

5. The method for directional mass transfer processing of fish meat based on magnetic field-assisted microwave mixing and ripening technology according to claim 3 is characterized in that: The wet salting comprises the following steps: The fish meat was immersed in 3% by mass salt water, and then subjected to vacuum and pulse circulation treatments, and then allowed to stand still.

6. The method for directional mass transfer processing of fish meat based on magnetic field-assisted microwave mixing and ripening technology according to claim 1, characterized in that: The pre-cooking is performed by turning on the alternating magnetic field for 0.5 h and stopping it for 3 h, which is repeated three times.

7. The method for directional mass transfer processing of fish meat based on magnetic field-assisted microwave mixing and cooking technology according to claim 1, characterized in that: The pre-cooking temperature is 4° C. and the humidity is 75-85%. The frequency of the alternating magnetic field is 50 Hz and the intensity is 0.2T.

8. The method for directional mass transfer processing of fish meat based on magnetic field-assisted microwave mixing and cooking technology according to claim 1, characterized in that: The ripening treatment liquid is obtained by fermenting the noni fruit and mixing it with old fragrant yellow or butter.

9. The method for directional mass transfer processing of fish meat based on magnetic field-assisted microwave mixing and cooking technology according to claim 1, characterized in that: The power of the microwave-assisted directional mass transfer ripening is 300 W, and an intermittent start-stop method of working for 15 seconds and stopping for 15 seconds is adopted, and the cycle is repeated 5 times.

10. The method for directional mass transfer processing of fish meat based on magnetic field-assisted microwave mixing and cooking technology according to claim 9, characterized in that: During the microwave-assisted directional mass transfer cooking process, the internal temperature of the fish meat is less than 45°C.

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