A process for the production of air-dried meat by contact ultrasonic coupling infrared assisted hot air drying

Abstract

The application discloses a kind of contact type ultrasonic coupling infrared auxiliary hot air drying production air-dried meat processes, belong to food processing technical field.The application is prepared by using the method of contact type ultrasonic coupling infrared auxiliary hot air drying, and the beef jerky obtained compared with traditional hot air drying method, drying time is significantly shortened to 360min, and product brightness is 1.2 times of hot air drying.At the same time, the texture and flavor substance content of the obtained product are obviously improved, and the product obtained by the method of the application shows significantly higher umami and salty taste than other groups.

Description

Technical Field

[0001] This invention relates to the field of food processing technology, specifically to a process for producing air-dried meat using contact ultrasonic coupled infrared-assisted hot air drying. Background Technology

[0002] As a typical naturally fermented cured meat product, the production process of dried meat involves dynamic changes in the microbial ecosystem. During the long fermentation process, through natural selection and prolonged domestication, a rich microbial community accumulates within the meat, including beneficial microbial communities such as lactic acid bacteria and yeasts. However, due to the open nature of the natural air-drying process, meat products are susceptible to insect infestation and environmental contamination. These instabilities pose challenges to the quality control and standardized production of dried meat in the context of modern industrialized production.

[0003] The existing technologies for drying meat mainly include the following methods:

[0004] In commercial practice, convection drying or hot air drying at around 35°C is widely adopted as the traditional mainstream processing method for air-dried meat products. However, this method has the following drawbacks: (1) Due to the low thermal conductivity of food, the limited heat transfer inside the product during convection heating leads to low energy utilization efficiency and a long drying time. (2) Long-term high-temperature treatment not only accelerates non-enzymatic browning and other heat-induced reactions, but also leads to the deterioration of food quality in many aspects, such as loss of flavor components (fat oxidation), color fading, and hardening of the outer shell.

[0005] Patent CN115997895A discloses a method for preparing microwave-infrared combined drying beef jerky with ultrasonic pretreatment. This method uses microwave heating and infrared combined heating to dry beef. However, this method has the following drawbacks: (1) The method is cumbersome to operate and requires frequent turning during the drying process; (2) The working temperature is high, which will cause energy waste and is not conducive to production in actual production; (3) Compared with the traditional hot air modification, this method has limited improvement in brightness value, only 9%; (4) This method has limited improvement in the texture and flavor of the obtained product.

[0006] In summary, there is an urgent need to provide a process for producing dried meat that can further improve the color, texture, and flavor of the product. Summary of the Invention

[0007] [Technical Issues]

[0008] The technical problem to be solved by the present invention is to provide a simple process for producing air-dried meat that improves color, texture and flavor.

[0009] [Technical Solution]

[0010] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0011] In a first aspect, the present invention provides a method for preparing air-dried meat, comprising the following steps:

[0012] Step S1: Cut the meat into strips to obtain a sample;

[0013] Step S2: The sample described in S1 is subjected to contact ultrasound-assisted infrared-hot air combined drying to obtain air-dried meat;

[0014] The contact ultrasound-assisted infrared-hot air combined drying includes: placing the sample on a contact ultrasonic vibration plate and performing infrared drying and hot air drying under ultrasonic conditions.

[0015] In one embodiment, step S1 includes: cutting the meat into strips, removing visible fat and fascia to obtain a sample.

[0016] In one embodiment, the infrared drying temperature is 30-40°C. Optionally, the infrared drying temperature is 35°C.

[0017] In one embodiment, the ultrasonic power distribution of the contact ultrasonic vibrating plate is 12.6 W / dm2.

[0018] In one embodiment, the contact ultrasonic vibrating plate has a diameter of 25 cm and a frequency of 20 kHz.

[0019] In one implementation, the ultrasound is performed under the following conditions: ultrasound for 5 seconds, then off for 5 seconds, and this cycle is repeated.

[0020] In one embodiment, the hot air drying temperature is 30-40°C. Optionally, the hot air drying temperature is 35°C.

[0021] In one embodiment, the sample weighs 5-15g. Optionally, the sample weighs 10g.

[0022] In one embodiment, the sample is a strip with a shape of 15mm × 15mm × 40mm.

[0023] In one embodiment, the contact ultrasonic-assisted infrared-hot air combined drying time is 320-400 min. Optionally, it is 360 min.

[0024] In one embodiment, the drying process is stopped when the moisture content of the sample drops to 50%.

[0025] In one embodiment, the meat mentioned in step S1 is beef.

[0026] In one embodiment, the dried meat has an umami amino acid content of not less than 23.58 mg / 100g, an amylose amino acid content of not less than 190.704 mg / 100g, and a bitter amino acid content of not less than 116.083 mg / 100g. Optionally, the dried meat has an umami amino acid content of 23.58 mg / 100g, an amylose amino acid content of 190.704 mg / 100g, and a bitter amino acid content of 116.083 mg / 100g.

[0027] In a second aspect, the present invention also provides dried meat prepared using the method described in the first aspect.

[0028] It should be understood that, within the scope of this invention, the above-described technical features of this invention and the technical features specifically described below (such as in the embodiments) can be combined with each other to form new or preferred technical solutions. Due to space limitations, they will not be described in detail here.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] (1) The method provided by the present invention significantly shortens the drying time and increases the drying uniformity.

[0031] (2) The method of the present invention can effectively improve the browning degree of the product color. CU-IRD can significantly improve the brightness value of the product. The brightness value of the CU-IRD group is 1.15 times that of the CT group and 1.20 times that of the HAD group. In addition, compared with other treatment groups, CU-IRD can also significantly improve the redness value of the product. The redness value of the CU-IRD group is 1.47, 1.42, and 1.15 times that of the HAD group, CU-HAD group, and IRD group, respectively.

[0032] (3) The method of the present invention can significantly reduce the shear force, hardness and chewiness of the product, while the elasticity and cohesiveness are not significantly affected, thereby reducing the hardening of the dried meat shell and improving the texture of the product.

[0033] (4) The method of the present invention can play a synergistic role, significantly increase the content of umami amino acids, sweet amino acids and free amino acids in the product, and reduce the content of bitter amino acids; at the same time, it increases the types and contents of volatile flavor substances.

[0034] (5) The method of the present invention can increase the umami and saltiness of the product by increasing the content of umami amino acids and reduce the bitterness of the product by decreasing the content of bitter amino acids. The method of the present invention can effectively avoid the use of sodium chloride by increasing the content of umami amino acids and reduce the requirements for the salt concentration of the pickling liquid. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of a device for contact ultrasonic-assisted infrared hot air drying (a. oven shell; b. internal structure), where 1-control panel, 2-axial fan, 3-air inlet, 4-K-type thermocouple, 5-infrared lamp, 6-ultrasonic vibrating plate, 7-beef sample, 8-air outlet.

[0036] Figure 2 This is a beef drying-time curve. HAD represents 35℃ hot air drying, CU-HAD represents contact ultrasound-assisted hot air drying, IRD represents infrared-assisted hot air drying, and CU-IRD represents contact ultrasound coupled with infrared-assisted hot air drying.

[0037] Figure 3 The moisture distribution of air-dried meat under different drying conditions is shown. 0, 25%, and 50% represent the weight loss during the drying process. HAD indicates 35℃ hot air drying, CU-HAD indicates contact ultrasound-assisted hot air drying, IRD indicates infrared-assisted hot air drying, and CU-IRD indicates contact ultrasound coupled with infrared-assisted hot air drying.

[0038] Figure 4 The effects of different drying methods on the types (A) and contents (B) of different volatile flavor compounds.

[0039] Figure 5 This is a heatmap representing the volatile flavor compounds in dried meat. The relative contents were calculated by globally standardizing all substances using the logarithm to base 4. Detailed Implementation

[0040] The present invention will now be described in further detail with reference to specific embodiments. The given embodiments are merely illustrative of the invention and not intended to limit its scope. The embodiments provided below can serve as a guide for further improvements by those skilled in the art and do not constitute a limitation of the invention in any way.

[0041] In this invention, the term "about" or "approximately" should be understood to include all values ​​within the permissible range of measurement error.

[0042] Unless otherwise specified, the experimental methods used in the following examples are conventional methods, performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Unless otherwise specified, the materials and reagents used in the following examples are commercially available.

[0043] Example:

[0044] Example 1

[0045] A method for producing dried meat using contact ultrasonic coupled infrared assisted hot air drying (CU-IRD), the method comprising the following steps:

[0046] (1) Raw material pretreatment: Remove visible fat and fascia from the raw beef and store it in a cold storage at -18℃. Before drying, thaw the meat at 4℃ and then cut it into strips of 15mm×15mm×40mm in size and weighing about 10±0.6g.

[0047] (2) Place the beef sample processed in step 1 in an oven. Figure 1 In this process, contact ultrasound-assisted infrared-hot air combined drying is performed. Specifically, the beef is placed on a contact ultrasonic vibrating plate, and infrared and hot air drying are coupled under ultrasonic conditions, as follows:

[0048] Ultrasonic conditions: The ultrasonic mode of the ultrasonic vibrating plate was set to 5s on and 5s off. The actual ultrasonic power distribution on the surface of the ultrasonic vibrating plate was 12.6 W / dm².

[0049] Infrared conditions: The infrared heating device consists of three identical infrared lamps. By adjusting the lamp parameters to a rated voltage of 74V, a rated power of 115W, a total length of 300mm, and a heating length of 230mm, and applying a voltage of 120V (actual power of 140W) to both ends of the series lamps, the final temperature of the beef sample on the ultrasonic vibration plate remained around 35℃ without significant fluctuations.

[0050] Hot air drying: regulated by an air conditioning unit, which includes an axial fan for a preheating device and a K-type thermocouple. The K-type thermocouple is connected to the dryer control panel to maintain the temperature of the dried air in the hot air drying system at a constant 35°C.

[0051] Following the standard isothermal drying procedure, the samples were placed in an oven at 105 degrees Celsius for 24 hours for constant temperature heat treatment. The average initial wet basis moisture content of the beef samples was measured to be 74.82 ± 0.63% (equivalent to approximately 297.14% dry basis moisture content). In this embodiment, the target drying degree for all samples was set to reduce the original weight by 50%, i.e., the desired moisture content was reduced to 50% (wb).

[0052] In order to obtain comprehensive data on the dynamic changes of moisture content of beef samples over time during the drying process, the samples were uniformly and evenly distributed in the drying container, and accurately weighed every 30 minutes.

[0053] Comparative Example 1

[0054] A method for commercially producing air-dried meat using hot air drying (HAD) drying, comprising the following steps:

[0055] The specific implementation method is the same as in Example 1, except that in step (2), ultrasonic and infrared drying are not used, and only hot air drying is used.

[0056] Comparative Example 2

[0057] A method for producing dried meat using ultrasound-assisted hot air drying (CU-HAD), the method comprising the following steps:

[0058] The specific implementation method is the same as in Example 1, except that in step (2), infrared drying is not used, but only ultrasonic and hot air drying are coupled.

[0059] Comparative Example 3

[0060] A method for producing dried meat by infrared-assisted hot air drying (IRD), the method comprising the following steps:

[0061] The specific implementation method is the same as in Example 1, except that in step (2), ultrasound is not used, and only infrared drying and hot air drying are coupled.

[0062] Example 3

[0063] The performance parameters of the experimental process and the final product of Examples 1 and Comparative Examples 1-3 were measured as follows:

[0064] 1. Determination of drying time and drying uniformity of products obtained by different drying methods

[0065] Experimental methods:

[0066] Drying time determination: Following the drying procedure in Example 1, the sample was accurately weighed every 30 minutes. The drying time is the time required for the sample to achieve a target dryness of 50% reduction in its original weight.

[0067] Drying uniformity determination: Two-dimensional proton density imaging analysis was performed on samples at the initial, mid-drying, and final stages (representing 0%, 25%, and 50% weight loss states, respectively) using a low-field nuclear magnetic resonance imaging analyzer (model NMI20-040H-I) at a constant temperature of 32℃. Specific pulse parameters for the SPIN-ECHO sequence were configured as follows: field of view (FOV) of 60 mm × 60 mm, repetition time (TR) of 500 ms, spin echo time (TE) of 20 ms, and number of repetitions (NS) of 4. For each sample, a 2 mm wide intermediate slice was selected. To improve image contrast, the generated original two-dimensional grayscale images were enhanced with pseudo-color using ImageJ image processing software to facilitate clearer and more intuitive identification and analysis of the proton density distribution characteristics within the samples.

[0068] Experimental results:

[0069] Beef drying-time curve as follows Figure 2 As shown, from Figure 2 The drying times for HAD, CU-HAD, IRD, and CU-IRD methods are 570 min, 480 min, 420 min, and 360 min, respectively. It is evident that the addition of contact ultrasound and infrared radiation in the CU-IRD method significantly shortens the total time, reducing the time cost by 36.84% compared to HAD.

[0070] Moisture distribution of air-dried meat under different drying conditions, as follows Figure 3 As shown, the redder the image, the higher the moisture content in that area; the bluer the image, the lower the moisture content. The signal intensity on the upper surface and side edges of the HAD group samples was significantly lower than that inside and at the bottom of the samples, accompanied by significant shrinkage. This is mainly because the hot air can only effectively remove moisture from the surface and sides of the samples, thus forming a hard shell on the surface of the HAD group samples. The uneven temperature distribution inside the samples hinders effective moisture transport, resulting in a larger moisture gradient inside. In contrast, the moisture gradient characteristics and shrinkage of the CU-IRD group samples were significantly reduced.

[0071] 2. Color detection of products obtained by different drying methods

[0072] Experimental method: The color attributes of the sample surface under different drying conditions were measured using a portable colorimeter (CR-400). Color values ​​are expressed as L* (brightness / darkness), a* (redness / greenness), and b* (yellowness / blueness).

[0073] Experimental results:

[0074] The results of brightness, redness, and yellowness values ​​of products obtained by different drying methods are shown in Table 1. Different letters in the same column indicate significant differences. CT represents fresh samples, HAD represents 35℃ hot air drying, CU-HAD represents contact ultrasound-assisted hot air drying, IRD represents infrared-assisted hot air drying, and CU-IRD represents contact ultrasound-coupled infrared-assisted hot air drying. As shown in Table 1, CU-IRD significantly improves the brightness value of the products; the brightness value of the CU-IRD group is 1.15 times that of the CT group and 1.20 times that of the HAD group. Furthermore, compared to other treatment groups, CU-IRD also significantly improves the redness value of the products; the redness value of the CU-IRD group is 1.47, 1.42, and 1.15 times that of the HAD, CU-HAD, and IRD groups, respectively.

[0075] Table 1. Results of lightness, redness, and yellowness values ​​of air-dried meat under different drying conditions.

[0076]

[0077] 3. Texture testing of products obtained by different drying methods

[0078] Experimental Methods: After drying, the beef jerky was cut into 10mm×10mm×10mm samples perpendicular to the fiber direction. The hardness, elasticity, cohesiveness, and chewiness were measured using a TA-XT Plus texture analyzer. Measurement Conditions: A P5 probe was used; the pre-measurement velocity was 2.0mm / s, the test velocity was 2.0mm / s, the post-measurement velocity was 10.0mm / s, the compression ratio was 40%, the shear induction force (trigger force) was 5.0g, and the measurement interval was 5.00s. Each sample was measured three times.

[0079] Experimental results:

[0080] The texture test results of products obtained by different drying methods are shown in Table 2. Different letters in the same column indicate significant differences. HAD represents 35℃ hot air drying, CU-HAD represents contact ultrasonic-assisted hot air drying, IRD represents infrared-assisted hot air drying, and CU-IRD represents contact ultrasonic-coupled infrared-assisted hot air drying. As shown in Table 2, CU-IRD significantly reduces the shear force, hardness, and chewiness of the product, while elasticity and cohesiveness are not significantly affected. In other words, CU-IRD can reduce the hardening of the dried meat's outer shell, thereby improving the product texture.

[0081] Table 2 Texture characteristics of air-dried meat under different drying conditions

[0082]

[0083]

[0084] 4. Detection of flavor substance content in products obtained by different drying methods

[0085] Experimental methods:

[0086] Determination of free amino acids: 4 g of dried meat sample was homogenized with 20 mL of 3% (w / v) sulfosalicylic acid (10000 rpm, 30 s). The homogenate was then centrifuged at 4 °C and 10000 rpm for 15 min using an Avanti JXN-26 ultra-high-speed refrigerated centrifuge. The supernatant was mixed with n-hexane, allowed to stand, and the lower aqueous phase was filtered through a 0.22 μm filter membrane. The concentration was determined using an automated amino acid analyzer (L-8900).

[0087] Determination of volatile flavor compounds: Volatile flavor compounds were extracted from the dried meat using headspace solid-phase microextraction (HS-SPME) with a gas chromatography-mass spectrometry (TSQ9000). 2g of minced meat sample was placed in a 20mL headspace vial, and 5μL of o-dichlorobenzene-methanol solution (100mg / L) was added as an internal standard. The headspace vial was equilibrated at 40℃ for 10min, and then the extraction head was exposed to the top of the vial for 5min. Finally, the SPME fiber head was transferred to the gas chromatograph inlet, and desorption was performed at 240℃ for 5min. Temperature program: Initial temperature 38℃, held for 13min, increased to 100℃ at a rate of 3℃ / min, held for 5min; then increased to 150℃ and 240℃ at rates of 4℃ / min and 10℃ / min, respectively. The carrier gas (He) flow rate was 1.0mL / min. Mass spectrometry conditions: EI, transfer line temperature 240℃, ion source temperature 240℃, mass scan range m / z 35~450. The spectra of the detected volatile substances were compared with the NIST I7 standard library for qualitative analysis.

[0088] Experimental results:

[0089] The amino acid content of products obtained by different drying methods is shown in Table 3. Different superscript letters in the same row represent significant differences (P<0.05). UAA: Umami amino acid (Asp, Glu); SAA: Sweet amino acid (Thr, Ser, Ala, Gly, Pro); BAA: Bitter amino acid (Lys, Ile, Val, Leu, Tyr, Phe, His, Arg, Met); OAA: Other amino acid (Cys); FAA: Free amino acid. As shown in Table 3, compared to the CU-HAD and IRD groups, the CU-IRD group showed a significant increase in the content of umami amino acids, sweet amino acids, and free amino acids, and the increase was greater than the sum of the increases in the CU-HAD and IRD groups. This indicates that the contact ultrasonic coupled infrared-assisted hot air drying method has a significant synergistic effect, which can increase the content of umami amino acids, sweet amino acids, and free amino acids in the product through synergistic effects. Furthermore, Table 3 shows that the content of bitter amino acids in both the CU-HAD and IRD groups increased significantly compared to the HAD group, with the IRD group showing the most significant increase, reaching 121.660±2.527 mg / 100g. However, the content of bitter amino acids in the CU-IRD group, which underwent ultrasonic treatment in addition to IRD treatment, decreased compared to IRD (116.083±1.660 mg / 100g). This indicates that the contact ultrasonic coupled infrared-assisted hot air drying method has a synergistic effect and can reduce the increase in bitter amino acid content caused by IRD.

[0090] Table 3. Free amino acid content in dried meat

[0091]

[0092] The results of the volatile flavor compound content detection of products obtained by different drying methods are shown in Table 4. Figure 4 , Figure 5 As shown, by Figure 4 and Figure 5 It was found that, compared with other groups, the CU-IRD group increased the diversity (39 substances) and total content (2568.10 μg / kg) of volatile flavor compounds in the dried meat. The addition of infrared radiation and ultrasound both had a positive impact on flavor, mainly due to changes in the types and amounts of some alkanes and esters. Throughout the drying process, the CU-IRD group accumulated the most abundant ketones, aldehydes, and esters; that is, the CU-IRD method results in a product with better aroma characteristics.

[0093] Table 4. Content and types of volatile flavor compounds in dried meat.

[0094]

[0095]

[0096] 5. Electronic tongue taste feature detection

[0097] Experimental Methods: An electronic tongue (SA402B) equipped with five potentiometric sensors (Umami AAE, Saltiness CT0, Sourness CA0, Bitterness CO0, and Astringency AE1) was used to determine the taste characteristics of different air-dried samples. The specific method is as follows: 5g of the pulverized sample was weighed and mixed thoroughly with 100mL of deionized water (12000rpm, 20s). The mixture was centrifuged in an ultra-high-speed refrigerated centrifuge (Avanti JXN-26) at 13000×g for 15min. The supernatant was filtered through a 0.22μm aqueous filter membrane and used for analysis.

[0098] Experimental results:

[0099] The results of the electronic tongue taste characteristic detection are shown in Table 5. Different superscript letters in the same row represent significant differences (P<0.05). As can be seen from the data in Table 5, the CU-IRD group exhibited the highest umami (11.217) and saltiness (7.497). This is because the content of umami amino acids (Asp, Glu) in the CU-IRD group was significantly higher than in other groups. Umami amino acids not only enhance umami but are also key to the formation of saltiness. Umami amino acids can be used as substitutes to reduce sodium content and retain saltiness. In Table 5, the CU-IRD group showed a significantly higher effect on increasing umami and saltiness compared to the HAD group, which further proves that the CU-IRD group can play a synergistic role, further increasing the umami and saltiness of the product. Bitterness is a common sensory defect in dried beef. In the electronic tongue scoring, the bitterness response values ​​and trends of different treatment groups differed from the content of bitter amino acids. This may be due to interference from other flavors (sweet amino acids). However, it can be clearly seen from Table 5 that the introduction of ultrasound in the CU-IRD group can further reduce the bitterness in the IRD group.

[0100] Table 5. Electronic tongue taste characteristics of air-dried meat after different treatments

[0101]

[0102] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the claims.

Claims

1. The application of a method for preparing air-dried meat in enhancing the flavor of air-dried beef, characterized in that, Includes the following steps: Step S1: Cut the beef into strips to obtain a sample; Step S2: The sample described in S1 is subjected to contact ultrasound-assisted infrared-hot air combined drying to obtain air-dried meat; The contact ultrasound-assisted infrared-hot air combined drying includes: placing the sample on a contact ultrasonic vibration plate and performing infrared drying and hot air drying under ultrasonic conditions. The enhancement of the flavor of dried beef includes increasing the umami and saltiness of dried beef and reducing the bitterness of dried beef. The infrared drying temperature is 30-40℃; The ultrasonic power distribution of the contact ultrasonic vibrating plate is 12.6 W / dm. 2 ; The ultrasound conditions are: ultrasound for 5 seconds, then off for 5 seconds, and this cycle repeats. The temperature of the hot air drying is 30-40℃; The contact ultrasonic-assisted infrared-hot air combined drying time is 320-400 min.

2. The application according to claim 1, characterized in that, The sample weighs 5-15 g.

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