阅读说明：本技术 一种利用超声波辅助热预制牛肉的方法 (Method for preparing beef by using ultrasonic-assisted heat ) 是由 蔡丹 刘景圣 张大力 刘回民 修琳 方晓敏 杨敬博 于 2020-10-28 设计创作，主要内容包括：本发明公开了一种利用超声波辅助热预制牛肉的方法,1)选取新鲜牛肉,加工成片；2)超声：将牛肉放入水或糊化的淀粉水溶液中超声,超声频率40 kHz,超声功率200w,水温小于55℃,超声时间为11~13s；3)将超声处理后的牛肉,放入到85~95℃的水中,煮10~15s；可即食或烹饪后食用,通过超声及水煮两步处理,处理后的肉剪切力降低,嫩度增加,口感好；处理后肉片未测出活菌。(The invention discloses a method for preparing beef by using ultrasonic-assisted heat, which comprises the following steps of 1) selecting fresh beef and processing the fresh beef into slices; 2) ultrasonic: putting beef into water or gelatinized starch water solution for ultrasonic treatment, wherein the ultrasonic frequency is 40kHz, the ultrasonic power is 200w, the water temperature is less than 55 ℃, and the ultrasonic time is 11-13 s; 3) putting the beef subjected to ultrasonic treatment into water at 85-95 ℃, and boiling for 10-15 s; the meat can be eaten instantly or after being cooked, and the shearing force of the treated meat is reduced, the tenderness is increased and the taste is good through two-step treatment of ultrasound and water boiling; no viable bacteria were detected in the treated pieces.)

1. A method for preparing beef by using ultrasonic-assisted heat, which comprises the following steps:

1) selecting fresh beef and processing into slices;

2) ultrasonic: putting beef into water for ultrasonic treatment, wherein the ultrasonic frequency is 40kHz, the ultrasonic power is 200w, the water temperature is less than 55 ℃, and the ultrasonic time is 11-13 s;

3) and (3) putting the beef subjected to ultrasonic treatment into constant-temperature hot water at 85-95 ℃ and carrying out water bath for 10-15 s.

2. The method for preparing beef by using ultrasonic-assisted heat as claimed in claim 1, wherein the method comprises the following steps: the beef in the step 2) is processed into the beef with the length multiplied by the width multiplied by the thickness =7cm multiplied by 4cm multiplied by 3 mm.

3. The method for preparing beef by using ultrasonic-assisted heat as claimed in claim 2, wherein the method comprises the following steps: the ultrasonic time in the step 2) is 12 s.

4. The method for preparing beef by using ultrasonic-assisted heat as claimed in claim 3, wherein the method comprises the following steps: the water temperature in the step 2) is less than 30 ℃.

5. The method for preparing beef by using ultrasonic-assisted heat as claimed in claim 4, wherein the method comprises the following steps: the constant temperature hot water in the step 3) is 90 ℃.

6. The method for preparing beef by using ultrasonic-assisted heat as claimed in claim 5, wherein the method comprises the following steps: the water bath in the step 3) is 10 s.

7. A method for preparing beef by using ultrasonic-assisted heat according to claim 1, 2, 3, 4, 5 or 6, characterized in that: the water in the step 2) is gelatinized starch water solution, and the concentration is 0.5-1%.

Technical Field

The invention belongs to the technical field of meat product processing, and particularly relates to a method for preparing beef by using ultrasonic-assisted heat.

Background

Ultrasonic waves convert electric energy into acoustic energy through a transducer, the energy is converted into small dense bubbles through a liquid medium, the small bubbles are rapidly burst to generate energy like small bombs, and therefore the effect of breaking cells and other substances is achieved.

Ultrasonic wave is an elastic mechanical wave in a substance medium, and is a wave form, so that it can be used for detecting physiological and pathological information of human body, i.e. diagnosing ultrasonic wave. Meanwhile, the ultrasonic energy is also an energy form, and when a certain dose of ultrasonic waves is transmitted in a living body, the function and the structure of the living body can be changed through the interaction between the ultrasonic energy and the energy, namely, the ultrasonic biological effect. The effect of ultrasound on cells mainly has thermal, cavitation and mechanical effects. The thermal effect is that when the ultrasound is transmitted in the medium, the friction force hinders the molecular vibration caused by the ultrasound, and part of the energy is converted into local high heat (42-43 ℃), because the critical lethal temperature of the normal tissue is 45.7 ℃, and the sensitivity of the tumor tissue is higher than that of the normal tissue, the metabolism of the tumor cells is obstructed at the temperature, the synthesis of DNA, RNA and protein is influenced, and the cancer cells are killed, and the normal tissue is not influenced. The cavitation effect is that under ultrasonic irradiation, vacuoles are formed in organisms, and mechanical shearing pressure and agitation are generated along with the vibration and violent implosion of the vacuoles, so that tumors bleed and tissues are disintegrated to cause necrosis. In addition, the cavitation bubbles generate instantaneous high temperature (about 5000 ℃) and high pressure (up to 500 × 104 Pa) when they rupture, which can thermally dissociate water vapor to generate OH radicals and H atoms, and the redox reaction caused by the OH radicals and H atoms can lead to polymer degradation, enzyme inactivation, lipid peroxidation and cell killing. The mechanical effect is the primary effect of ultrasound, and during the propagation process of the ultrasound, medium particles are alternately compressed and stretched to form pressure change, which causes damage to cell structures. The strength of the killing effect is closely related to the frequency and the intensity of the ultrasound.

In the process of processing the fresh meat, microorganisms on the surface of the fresh meat often exceed the national specified microorganism standards due to the cross contamination of the microorganisms on the body surface of slaughtered animals to the slaughtered fresh meat. The prior measures for removing the pollution by microorganisms can influence the quality of fresh meat. During the processing of the fresh meat, substances which are harmful to the health of operators and consumers are not generated.

Tenderness of meat is the old and tender taste of meat when eating, reflects the texture of meat, and is determined by structural characteristics of various proteins in muscle. It determines the final sensory quality of cooked and processed meat products, and is the most common index for consumers to judge the quality of meat. Factors affecting the tenderness of meat include animal species, age, sex, genotype, feeding mode, meat mass location, ketone body suspension mode, electrical stimulation, collagen amount and its solubility, sarcomere length, mechanical action, chemical action, freezing, etc.

Ultrasonic tenderization is a new technology, and is gradually applied to food processing. The main principle of ultrasonic tenderization is the cavitation effect and the mechanical effect of ultrasonic waves. There are often small bubbles of liquid that are vacuum or contain small amounts of gas or vapor, and these small bubbles are not of uniform size. When ultrasonic wave with a certain frequency acts on liquid, only small bubbles with proper size can generate resonance phenomenon, and the small bubbles with the size larger than the resonance size gradually become bigger under the action of the ultrasonic wave. The maximum value of the shearing force can be reduced in the shortest maturation time by applying ultrasonic treatment, the beef cooking loss is reduced, and the color is not influenced. Generally, the low-frequency (20-100 kHz) and high-power (100W-10 kW) ultrasonic treatment is effectively and feasible for improving the muscle tenderness. The proposed tenderization mechanism is mainly that the ultrasonic wave generates high-speed shearing, pressure and temperature effects to break the myofibril structure through the cavitation effect, weaken connective tissues and increase the release of calcium ions in sarcoplasm, and promote the activity of muscle endogenous protease such as cathepsin and calcium-activated protease.

However, in the ultrasonic process, a large amount of heat is generated in a short time under the action of ultrasonic waves, and the temperature during ultrasonic treatment is difficult to control. Therefore, domestic and foreign research has focused on the effect of changes in frequency and power on meat tenderization.

Disclosure of Invention

The invention aims to provide a method for preparing beef by using ultrasonic-assisted heat in order to solve the problem of poor temperature control during ultrasonic treatment of the beef.

A method for preparing beef by using ultrasonic-assisted heat, which comprises the following steps:

1) selecting fresh beef and processing into slices;

2) ultrasonic: putting beef into water for ultrasonic treatment, wherein the ultrasonic frequency is 40kHz, the ultrasonic power is 200w, the water temperature is less than 55 ℃, and the ultrasonic time is 11-13 s;

3) putting the beef subjected to ultrasonic treatment into constant-temperature hot water at 85-95 ℃ and carrying out water bath for 10-15 s;

step 2) beef is processed into a length multiplied by width multiplied by thickness =7cm multiplied by 4cm multiplied by 3 mm;

the ultrasonic time in the step 2) is 12 s;

the water temperature in the step 2) is less than 30 ℃;

the constant temperature hot water in the step 3) is 90 ℃;

the water bath in the step 3) is 10 s;

the water in the step 2) is gelatinized starch water solution, and the concentration is 0.5-1%.

The invention provides a method for preparing beef by using ultrasonic-assisted heat, which comprises the following steps of 1) selecting fresh beef and processing the fresh beef into slices; 2) ultrasonic: putting beef into water or gelatinized starch water solution for ultrasonic treatment, wherein the ultrasonic frequency is 40kHz, the ultrasonic power is 200w, the water temperature is less than 55 ℃, and the ultrasonic time is 11-13 s; 3) putting the beef subjected to ultrasonic treatment into water at 85-95 ℃, and boiling for 10-15 s; the meat can be eaten instantly or after being cooked, and the shearing force of the processed meat is reduced, the tenderness is increased and the taste is good through two-step processing of ultrasound and water bath; no viable bacteria were detected in the treated pieces.

Drawings

FIG. 1 the effect of different ultrasonic frequencies on beef tenderness;

FIG. 2 the effect of different ultrasonic powers on beef tenderness;

FIG. 3 the effect of different ultrasound temperatures on beef tenderness;

FIG. 4 the effect of different ultrasound media on the tenderness of fresh meat;

FIG. 5 effect of different ultrasound media on water binding of fresh meat;

FIG. 6 the effect of different ultrasound media and pH on the tenderness of fresh meat;

FIG. 7 the effect of different ultrasound media and pH on the water binding capacity of fresh meat;

FIG. 8 results of the effect of two pretreatment methods on tenderness of meat slices;

figure 9 results of the effect of two pretreatment methods on the water binding capacity of meat slices.

FIG. 10 results of the effect of two different media on tenderness of meat pieces.

Detailed Description

Example 1 optimization experiment of fresh meat processing conditions

Experimental equipment: KQ-300VDE type double-frequency numerical control ultrasonic cleaner (frequency is 45KHz, 28 KHz) ultrasonic instruments of Kunshan city, Inc.; KQ-3200B ultrasonic cleaner (40 KHz) Tianjin Atlants instruments ltd; ultrasonic cell crusher (20 KHz) Ningbo Xinzhi Biotech Co., Ltd.

The fresh meat is treated by ultrasonic waves, and because factors influencing the quality of the fresh meat comprise ultrasonic frequency, ultrasonic power, ultrasonic time, temperature and the like, experiments are designed according to the factors, and the influence of the factors on the tenderness and the water retention of the fresh meat is discussed;

pretreatment: selecting fresh beef (cucumber strips) purchased from a supermarket; processing beef on clean meat cutting plate, cutting into slices with length × width × thickness =7cm × 4cm × 3mm, and removing tendon, fat tissue and inedible part; immersing meat in a beaker filled with water or other solution, wherein the direction of muscle fiber is parallel to the direction of an ultrasonic probe, and placing the beaker on a tank rack in an ultrasonic machine, wherein the temperature of a machine tank is room temperature; setting ultrasonic frequency, ultrasonic power and ultrasonic time; the control is carried out by taking untreated fresh meat slices as follows:

influence of different ultrasonic frequencies on tenderness of beef

Setting ultrasonic frequency as variable, 20, 28, 40, 45KHz respectively, and setting at room temperature (without addingHeat) and 200w, respectively carrying out ultrasonic treatment for 6, 8, 10, 12, 14, 16 and 18s, measuring the shearing force by using a shearing force measuring instrument, and evaluating the tenderness of the fresh meat; the results are shown in FIG. 1; as can be seen from FIG. 1, the shear force values of all groups of meat samples tend to decrease and then increase along with the ultrasonic treatment, and the difference is significant when the meat samples are treated at 20 KHz and 28KHz compared with the meat samples without ultrasonic treatment (P is a significant difference)<0.05), the shear force value was higher than that of the control group, probably because the tenderizing effect of the low-frequency, short-time ultrasonic treatment on the beef was limited to the surface only, and the tenderizing effect was not so significant. 40. The shear force of the meat sample of the 45 KHz-treated group was significantly lower than that of the un-sonicated group (PLess than 0.05), the microstructure of the muscle fiber can be destroyed due to ultrasonic treatment with certain intensity, and the myofibril is broken, thereby improving the beef tenderness. The lowest shear value of 12s ultrasonic shear force is the best meat tenderness under the condition of 40 KHz.

Second, influence of different ultrasonic powers on beef tenderness

Setting ultrasonic power as variable, respectively 200, 300, 400 and 500w, respectively performing ultrasonic treatment for 6, 8, 10, 12, 14, 16 and 18s at room temperature (without heating) and 40KHz, measuring shearing force with a shearing force measuring instrument, and evaluating the tenderness of fresh meat; the results are shown in FIG. 2;

as can be seen from fig. 2, the shear force values of all the groups of meat samples tend to decrease and then increase as the ultrasonic treatment progresses; after the ultrasonic time exceeds 10s, the meat sample is processed at the power of 300w-500w, and the shearing force value is obviously larger than that of the un-ultrasonic group (p < 0.05), probably because the protein in the meat is denatured due to the overhigh ultrasonic power and the tenderness of the meat is adversely affected; when the power is 200w, the measured shear force value is obviously lower than that of a non-ultrasonic group (p is less than 0.05), the shear force value is the smallest at 12s ultrasonic time, the tenderness of meat is the best, and the cavity effect generated by ultrasonic treatment with certain intensity enables myofibrils to be broken at a Z line, the muscle structure tissue becomes loose, and the beef tenderizing effect can be well achieved.

Influence of different ultrasonic temperatures on beef tenderness

Setting ultrasonic temperature as variable, respectively 60, 70, 80, 85, 90, 95 and 100 ℃, respectively performing ultrasonic treatment for 6, 8, 10, 12, 14, 16 and 18 seconds under the condition of 40KHz 200w, measuring the shearing force by using a shearing force measuring instrument, and evaluating the tenderness of fresh meat; as shown in FIG. 3, it can be seen that the shear force value is the smallest and the meat tenderness is the best when the temperature is 90 ℃ and ultrasonic waves are applied for 12s, which indicates that the ultrasonic treatment under the condition has good tenderizing effect on the meat sample, because the salt-soluble protein in the muscle is dissolved out under the condition of 90 ℃, the tenderness and the water retention of the meat can be improved.

In summary, the conditions for the selected sonication were: the ultrasonic power is 200w, the ultrasonic frequency is 40KHz, and the ultrasonic temperature is 90 ℃.

Influence of four, different ultrasonic media on fresh meat quality

1. Effect of different ultrasonic media on tenderness of fresh meat

Adding 5g of flour into 500mL of water, stirring uniformly, heating to boil, cooling to room temperature, and supplementing water to 500 mL; adding 5g of starch into 500mL of water, stirring uniformly, heating to boil, cooling to room temperature, and then supplementing water to 500 mL; respectively putting the sliced meat into two media (replacing water) of flour or starch solution, and carrying out ultrasonic treatment on the fresh meat;

respectively carrying out ultrasonic treatment for 6, 8, 10, 12, 14, 16 and 18 seconds at the temperature of 90 ℃ at 40KHz and 200w, measuring the shearing force by using a shearing force measuring instrument, and evaluating the tenderness of the fresh meat; the results are shown in fig. 4, which shows that when meat pieces are placed in flour or starch solution for ultrasonic treatment, the shear force values are significantly lower than those of the ultrasonic group without ultrasonic treatment and with water as a medium (P < 0.05), indicating that starch and flour both act to tenderize beef, and that starch is more effective than flour in tenderizing beef, and that at 12s starch has the lowest shear force value and beef tenderness is the best.

2. Effect of different ultrasound Medium on Water holding Properties of fresh meat

Adding 5g of flour into 500mL of water, stirring uniformly, heating to boil, cooling to room temperature, and supplementing water to 500 mL; adding 5g of starch into 500mL of water, stirring uniformly, heating to boil, cooling to room temperature, and then supplementing water to 500 mL; respectively putting the sliced meat into two media (the function of replacing water) of flour or starch solution, and carrying out ultrasonic treatment on the fresh meat;

respectively carrying out ultrasonic treatment for 6, 8, 10, 12, 14, 16 and 18 seconds at the temperature of 90 ℃ at 40KHz and 200w, respectively measuring the weight of the sliced meat before and after the ultrasonic treatment, calculating the cooking loss, and evaluating the water retention; as a result, as shown in fig. 5, as the ultrasonic treatment proceeded, the cooking loss of the meat samples of all groups decreased, and the meat samples treated with flour and starch were significantly lower than that of the non-ultrasonic group (P < 0.05), and the water retention was higher than that of the non-ultrasonic group; when the ultrasonic wave is carried out for 6s, the cooking loss of the meat slices added with the starch is less than that of the meat slices added with the flour; during the ultrasonic treatment for 8-18 s, the water holding effect of the meat slices added with the flour is better than that of the meat slices added with the starch, and the difference value of the cooking loss is minimum during the ultrasonic treatment for 12 s; the ultrasonic treatment with certain intensity and the auxiliary action of flour or starch can change the microstructure of muscle tissue, break muscle fiber and improve the water retention of meat.

3. Effect of different ultrasound Medium and PH on beef quality

According to the experiment, the starch has better effect on tenderness and water retention after the meat slices are subjected to ultrasonic treatment; therefore, preparing starch solution with the concentration of 1 percent and starch solution with the concentration of 2 percent respectively and fine powder solution with the concentration of 1 percent and fine powder solution with the concentration of 2 percent respectively, stirring uniformly, heating to boil, cooling to room temperature, and supplementing water to the corresponding volume to ensure that the concentration is not changed; respectively putting the sliced meat into the solution (replacing the action of water) to carry out ultrasonic treatment on the fresh meat;

taking the pH value of the solution as a variable, wherein the pH values are respectively 6, 6.5, 7, 7.5 and 8, and carrying out ultrasonic treatment for 12s at the temperature of 90 ℃ under the conditions of 40KHz and 200 w; after ultrasonic processing, measuring the shearing force by using a shearing force measuring instrument, and evaluating the tenderness of the fresh meat; the results are shown in FIG. 6, which shows that the shear force values of physiological saline, 1% clarified flour and 2% clarified flour tend to increase and decrease first and then, and 1% starch and 2% starch tend to decrease and increase first and then, respectively, by ultrasonication under different pH conditions; at pH 7, the 1% starch shear value is lowest and the meat tenderness is best.

Evaluating the water holding capacity of the sliced meat by calculating the cooking loss; the results (FIG. 7) show that the cooking loss of the meat pieces in the starch and farinaceous solutions increases and the water binding capacity decreases, both with increasing pH, and at pH 6, the cooking loss of 1% starch is the lowest and the water binding capacity is the best; the cooking loss of the meat slices in the normal saline tends to increase after decreasing, the cooking loss is minimum when the pH is 7, and the 1% starch solution is slightly higher than the normal saline.

In summary, the optimized ultrasound conditions were: the ultrasonic frequency is 40KHz, the ultrasonic power is 200w, the temperature is 90 ℃, the ultrasonic medium is 1% starch solution, and the pH value of the solution is 6-7.

Example 2 method for preparing beef by using ultrasonic-assisted heat

1) Pretreatment: selecting fresh beef (cucumber strips) purchased from a supermarket; processing beef on clean meat cutting plate, cutting into slices with length × width × thickness =7cm × 4cm × 3mm, and removing tendon, fat tissue and inedible part;

2) ultrasonic: putting beef into 500mL of water, and performing ultrasonic treatment at the ultrasonic frequency of 40kHz, the ultrasonic power of 200w, the water temperature of 24 ℃ and the ultrasonic time of 12 s;

3) putting the beef subjected to ultrasonic treatment into constant-temperature hot water at 90 ℃ and heating for 10 s;

4) the heated sliced meat can be eaten.

Example 3 method for preparing beef by using ultrasonic-assisted heat

1) Pretreatment: selecting fresh beef (cucumber strips) purchased from a supermarket; processing beef on clean meat cutting plate, cutting into slices with length × width × thickness =7cm × 4cm × 3mm, and removing tendon, fat tissue and inedible part;

2) solution preparation: adding 5g of starch into 500mL of water, stirring uniformly, heating to boil, cooling to room temperature, and then supplementing water to 500 mL;

3) ultrasonic: immersing meat into a beaker of the starch solution prepared in the step 2), placing the beaker on a tank bracket in an ultrasonic machine, controlling the temperature of a machine tank to be less than 10 ℃, and measuring by using a wall-hanging thermometer; setting ultrasonic frequency of 40KHz, ultrasonic power of 200w and ultrasonic time of 12 s;

4) after the ultrasonic treatment is stopped, taking out the meat slices, adding the meat slices into constant-temperature hot water at 90 ℃, and heating for 12 s;

5) the heated meat slices can be eaten instantly or cooked.

Example 4 method for preparing beef by using ultrasonic-assisted heat

1) Pretreatment: selecting fresh beef (cucumber strips) purchased from a supermarket; processing beef on clean meat cutting plate, cutting into slices with length × width × thickness =7cm × 4cm × 3mm, and removing tendon, fat tissue and inedible part;

2) solution preparation: adding 5g of starch into 500mL of water, stirring uniformly, heating to boil, cooling to room temperature, and then supplementing water to 500 mL;

2) ultrasonic: immersing meat into a beaker of the starch solution prepared in the step 2), placing the beaker on a tank bracket in an ultrasonic machine, controlling the temperature of a machine tank to be 90 ℃, and measuring by using a wall-mounted thermometer; setting ultrasonic frequency of 40KHz, ultrasonic power of 200w and ultrasonic time of 12 s;

4) the heated sliced meat can be eaten.

Example 5 comparison of fresh meat tenderness to Water holding Properties

Tenderness was determined using the meat slices prepared in examples 2 and 3 (at least 10 slices per group) as sample 1 and sample 2, respectively (untreated meat slices were used as control groups); tenderness results are shown in fig. 10; as can be seen from the figure, the shear force of both samples 1 and 2 is significantly reduced compared to the control, with sample 1 having a slightly lower shear force than sample 2; the results show that the addition of starch is beneficial to improving the tenderness of the meat slices;

the meat pieces prepared in examples 3 and 4 (at least 10 pieces per group) were used as sample a and sample b, respectively (untreated meat pieces were used as control group), and tenderness and water holding capacity were measured; tenderness results are shown in FIG. 8; as can be seen from the figure, the shear force of samples a and b is significantly reduced compared to the control group, and the shear force of sample a is slightly higher than that of sample b but the difference is not significant; the results show that ultrasound is beneficial to improving the tenderness of the meat slices; the water binding capacity was measured, and the results are shown in FIG. 9; as can be seen from the figure, the cooking loss of the samples a and b is significantly reduced compared to the control group, and is significantly lower than the control group, which indicates that the microstructure of the muscle tissue can be changed due to the ultrasonic treatment with a certain intensity, so that the muscle fiber is broken, and the water holding capacity of the meat is improved; the boiling loss of the sample a is less than that of the sample b, and the water retention is better, which indicates that the mouthfeel is influenced because the sample b is subjected to ultrasonic treatment at 90 ℃, and the ultrasonic treatment can generate heat to cause instantaneous temperature rise and temperature is not easy to control, so that the water retention of the meat slices is reduced.

EXAMPLE 6 Total colony count determination

The number of colonies was determined using the meat slices prepared in examples 2, 3 and 4 (at least 10 slices per group) as samples 1 to 3 (untreated meat slices were used as a control group). The slices with the same size are selected from the slices with the size of length, width and thickness =7cm, 4cm and 3 mm. Ensuring that the quality difference is not more than 0.1g, adding the sample into a sterile homogenizing bottle, adding sterile diluent to 250g, homogenizing for 1-2 min to ensure that the sample is well dispersed, wherein the dilution is 1: 10; and (3) putting 1.0mL of the diluent into 2 sterilization plates respectively, pouring the composite culture medium with the total number of bacterial colonies, culturing for 12 hours in an incubator at 36 +/-1 ℃, and counting to obtain the detection result of the total number of the bacterial colonies. The results of the total number of colonies are shown in table 1, and the presence of colonies was not detected in any of the treated meat slices, so that the meat slices treated by the above method had a good bacteriostatic effect.

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