Preparation method of cicada pupa leisure snacks based on infrared-ultraviolet cooperative treatment and staged drying

Abstract

The invention provides a preparation method of cicada pupa leisure snacks based on infrared-ultraviolet cooperative treatment and staged drying, and belongs to the technical field of food. The preparation method of the cicada pupa leisure snack comprises the following steps: adding cicada pupa into saline water for soaking to obtain the cicada pupa activated by the saline water; performing infrared treatment on the cicada pupa activated by the saline water, and then performing ultraviolet treatment; seasoning and dipping the cicada pupa subjected to ultraviolet treatment, and then drying to obtain the cicada pupa leisure snack. The drying comprises first-stage drying and second-stage drying. According to the preparation method, the cicada pupas are seasoned and soaked after infrared treatment and ultraviolet treatment, so that nutritional ingredients in the cicada pupas can be reserved to the greatest extent while moisture is removed, and the flavor of the cicada pupas is better improved; the cicada pupas are dried by stages, so that the consistency of the crispness of the cicada pupas is favorably kept. According to the preparation method, nutritional ingredients in the cicada pupa can be reserved to the maximum extent, meanwhile, the crispness of the cicada pupa can be remarkably improved, and the flavor of the cicada pupa is improved.

Description

Technical Field

[0001] The invention belongs to the field of food technology, and in particular relates to a method for preparing cicada pupa snacks based on infrared-ultraviolet coordinated treatment and staged drying. Background Art

[0002] Cicada pupae have extremely high nutritional value and are a high-quality natural high-protein food. Cicada pupae are high in protein and low in fat, with a protein content of up to 60% to 70%, and contain essential amino acids, unsaturated fatty acids, vitamins and minerals.

[0003] Currently, conventional methods for processing cicada pupae include frying and grilling. These methods result in a significant loss of nutrients and a high fat content, making them unsuitable for modern healthy snacks. Furthermore, the commonly used preparation process for cicada pupae, which involves marinating and then drying them at high temperatures, often results in a hard exterior and a soft interior, unstable crispness, and uneven seasoning penetration, resulting in poor edible quality. Therefore, providing a cicada pupae processing method that can improve the flavor of cicada pupae while increasing the nutritional value of cicada pupae foods is of great significance for the promotion of cicada pupae products. Summary of the Invention

[0004] In view of the defects in the prior art, the object of the present invention is to provide a method for preparing cicada pupae, which can improve the flavor of cicada pupae and increase the nutritional value of cicada pupae.

[0005] The purpose of the present invention is achieved through the following technical solutions:

[0006] The present invention provides a method for preparing a cicada pupa snack, comprising the following steps:

[0007] adding cicada pupae into salt water and soaking them to obtain salt water-activated cicada pupae;

[0008] The salt-water activated cicada pupae were subjected to infrared treatment;

[0009] The infrared-treated cicada pupae were then treated with ultraviolet light;

[0010] The cicada pupae treated with ultraviolet light are seasoned and impregnated and then dried to obtain cicada pupae snacks;

[0011] The drying includes first-stage drying and second-stage drying; the drying temperature of the first stage is 43-47° C.; the drying time of the first stage is 1.5-3.0 hours; the drying temperature of the second stage is 48-52° C.; the drying time of the second stage is 1.3-1.7 hours.

[0012] Preferably, the wavelength of the infrared treatment is 760-800 μm; the irradiation intensity of the infrared treatment is 30-40 mW / cm 2The infrared treatment time is 10 to 14 minutes; the wavelength of the ultraviolet treatment is 265 to 270 nm; the irradiation intensity of the ultraviolet treatment is 30 to 40 mW / cm 2 ; The ultraviolet treatment time is 18 to 22 minutes.

[0013] Preferably, the mass concentration of salt in the brine is 3% to 5%, and the mass concentration of citric acid is 0.04% to 0.06%; and the soaking time is 8 to 12 minutes.

[0014] Preferably, the seasoning impregnation method comprises mixing cicada pupae with a seasoning liquid for impregnation; the mass volume ratio of the cicada pupae to the seasoning liquid is 1 kg:180-200 mL.

[0015] Preferably, the seasoning liquid includes a spicy seasoning liquid; calculated by mass, the spicy seasoning liquid comprises: 13 to 17 parts of chili powder, 6 to 10 parts of pepper powder, 6 to 10 parts of salt, 4 to 6 parts of white sugar, 2 to 4 parts of yeast extract and 190 to 210 parts of water.

[0016] Preferably, the seasoning impregnation method of the spicy seasoning liquid includes vacuum impregnation; the time of the vacuum impregnation is 10 to 14 minutes.

[0017] Preferably, the seasoning liquid includes a five-spice seasoning liquid; calculated by mass, the five-spice seasoning liquid comprises: 10-14 parts of five-spice powder, 4-6 parts of cinnamon powder, 2-4 parts of star anise powder, 5-7 parts of salt, 3-5 parts of rock sugar and 170-190 parts of water.

[0018] Preferably, the five-spice seasoning liquid seasoning impregnation method includes stirring and impregnation at normal pressure; the time of stirring and impregnation at normal pressure is 16 to 20 minutes; and the rotation speed of stirring and impregnation at normal pressure is 25 to 35 rpm.

[0019] The present invention provides application of the preparation method described in the above technical solution in improving the quality of cicada pupae.

[0020] Preferably, improving the quality of cicada pupae includes improving the flavor of cicada pupae and / or increasing the nutritional value of cicada pupae.

[0021] Beneficial effects of the present invention:

[0022] The present invention provides a preparation method of cicada pupa snacks, comprising the following steps: adding cicada pupae into salt water and soaking them to obtain salt water-activated cicada pupae; subjecting the salt water-activated cicada pupae to infrared treatment; subjecting the infrared-treated cicada pupae to ultraviolet treatment; seasoning and impregnating the ultraviolet-treated cicada pupae, and then drying them to obtain the cicada pupa snacks; the drying comprises first-stage drying and second-stage drying; the drying temperature of the first-stage drying is 43-47° C.; the drying time of the first-stage drying is 1.5-3.0 hours; the drying temperature of the second-stage drying is 48-52° C.; and the drying time of the second-stage drying is 1.3-1.7 hours. The present invention performs infrared treatment in the preparation of cicada pupa snacks, which can quickly reduce the moisture in the cicada pupae while retaining the nutrients in the cicada pupae, causing the protein to be slightly denatured; performs ultraviolet treatment, which can kill most of the bacteria in the cicada pupae; performs seasoning and impregnation on the cicada pupae after the infrared treatment and ultraviolet treatment, which can better improve the flavor of the cicada pupae; by drying the cicada pupae in stages, it is beneficial to maintain the consistency of the crispness of the cicada pupae, wherein the first drying stage can form crispness on the surface of the cicada pupae; the second drying stage can further improve the crispness of the cicada pupae; the overall temperature of the drying method is relatively low, and the nutrients in the cicada pupae can be retained to the greatest extent, thereby improving the nutritional value of cicada pupae food. In summary, the preparation method provided by the present invention can improve the flavor of cicada pupae while also improving the nutritional value of cicada pupae. DETAILED DESCRIPTION

[0023] The present invention provides a method for preparing a cicada pupa snack, comprising the following steps:

[0024] adding cicada pupae into salt water and soaking them to obtain salt water-activated cicada pupae;

[0025] The salt-water activated cicada pupae were subjected to infrared treatment;

[0026] The infrared-treated cicada pupae were then treated with ultraviolet light;

[0027] The cicada pupae treated with ultraviolet light are seasoned and impregnated and then dried to obtain cicada pupae snacks;

[0028] The drying includes first-stage drying and second-stage drying; the drying temperature of the first stage is 43-47° C.; the drying time of the first stage is 1.5-3.0 hours; the drying temperature of the second stage is 48-52° C.; the drying time of the second stage is 1.3-1.7 hours.

[0029] The present invention involves soaking cicada pupae in salt water to obtain saltwater-activated cicada pupae. The present invention does not specifically limit the source of the cicada pupae; any commercially available product in the art may be used. As an optional embodiment of the present invention, the cicada pupae may be fresh cicada pupae weighing ≤0.5g and ≤3cm in length; the cicada pupae may have intact, undamaged skin. In the embodiments of the present invention, cicada pupae of uniform size are preferably used to ensure uniform flavor absorption during subsequent saltwater soaking. This ensures consistent heating and dehydration during infrared and ultraviolet treatment and staged drying, minimizing variations in crispness and flavor due to individual differences. After obtaining the cicada pupae, the present invention preferably cleans them. The present invention does not specifically limit the cleaning method; any conventional cleaning method in the art may be used. As an optional embodiment of the present invention, the cleaning method may include first rinsing with running water, followed by ultrasonic cleaning; the running water rinsing may be repeated three times, each lasting 1 minute; the ultrasonic cleaning frequency may be 40kHz; and the ultrasonic cleaning duration may be 3 minutes. Through this cleaning method, the present invention can reduce impurity residues on the surface of the cicada pupae to ≤0.1%. After cleaning is completed, clean cicada pupae are obtained.

[0030] After obtaining the cleaned cicada pupae, the present invention adds the cicada pupae to salt water for soaking to obtain salt water-activated cicada pupae. As an optional embodiment of the present invention, the mass concentration of table salt in the salt water can be 3% to 5%, or 4%, and the mass concentration of citric acid can be 0.04% to 0.06%, or 0.05%. As an optional embodiment of the present invention, the soaking time can be 8 to 12 minutes, or 10 minutes. The present invention adds citric acid to the salt water mainly to adjust the pH to 5.5-6.0, inhibit enzyme activity, and improve epidermal permeability. The present invention uses the salt water for soaking to achieve preliminary seasoning, inhibit enzyme activity, and improve epidermal permeability, laying the foundation for subsequent infrared and ultraviolet treatment and seasoning penetration.

[0031] After obtaining the salt water activated cicada pupae, the present invention performs infrared treatment on the salt water activated cicada pupae. The present invention preferably performs infrared treatment on the cicada pupae after spreading them; the spreading thickness can be 1.8 to 2.2 cm, or 1.8, 1.9, 2.0, 2.1, or 2.2 cm; the wavelength of the infrared treatment can be 760 to 800 μm, or 780 μm; the irradiation intensity of the infrared treatment can be 30 to 40 mW / cm 2 , or 35mW / cm 2The infrared treatment time can be 10 to 14 minutes, or can be 10, 11, 12, 13, or 14 minutes. The present invention can reduce the moisture content of cicada pupae to 60% to 65% by subjecting them to infrared treatment while retaining their nutrients, causing slight protein denaturation, which is beneficial for subsequent processing to improve the flavor of the cicada pupae.

[0032] After obtaining the infrared-treated cicada pupae, the present invention subjects the infrared-treated cicada pupae to ultraviolet light treatment. The paving thickness of the cicada pupae subjected to ultraviolet light treatment in the present invention can be 1.8 to 2.2 cm, or 1.8, 1.9, 2.0, 2.1, or 2.2 cm. As an optional embodiment of the present invention, the wavelength of the ultraviolet light treatment can be 265 to 270 nm, or 265, 266, 267, 268, 269, or 270 nm, and the irradiation intensity of the ultraviolet light treatment can be 30 to 40 mW / cm 2 , or 35mW / cm 2 ; The time of the ultraviolet treatment can be 18 to 22 minutes, or 18, 19, 20, 21 or 22 minutes. The present invention performs ultraviolet treatment on cicada pupae mainly to kill bacteria and other microorganisms in the cicada pupae, thereby helping to extend the shelf life of the cicada pupae; at the same time, ultraviolet treatment can promote protein cross-linking and optimize the structure: high-energy radiation of ultraviolet rays (wavelength 265 to 270 nm) can induce covalent cross-linking between protein molecules on the surface of cicada pupae, and synergistically improve the protein cross-linking degree with infrared treatment (15% to 20% higher than that of single treatment), making the tissue structure of cicada pupae denser, laying a structural foundation for the formation of a uniform crisp shell in the subsequent drying stage; ultraviolet treatment can enhance epidermal permeability: ultraviolet irradiation can slightly damage the cuticle structure of the cicada pupae epidermis, increase its porosity by about 30%, and significantly improve the permeability of the epidermis to the seasoning liquid. For example, in spicy seasoning, the chili powder penetration rate can reach 90% when the ultraviolet-treated cicada pupae are vacuum-impregnated, ensuring that the flavor components penetrate evenly into the internal tissue.

[0033] The invention can also significantly improve the degree of light cross-linking of proteins on the surface of cicada pupae by sequentially subjecting cicada pupae to infrared treatment and ultraviolet treatment, thereby facilitating improvement of the flavor of the cicada pupae in subsequent seasoning and drying processes.

[0034] After obtaining ultraviolet-treated cicada pupae, the present invention seasons and impregnates the ultraviolet-treated cicada pupae and then dries them to produce a cicada pupa snack. As an optional embodiment of the present invention, the seasoning and impregnation method includes mixing the cicada pupae with a seasoning liquid and then impregnating them. The mass-to-volume ratio of the cicada pupae to the seasoning liquid can be 1 kg:180-200 mL, or can be 1 kg:180 mL, 1 kg:190 mL, or 1 kg:200 mL. As an optional embodiment of the present invention, the seasoning liquid includes a spicy seasoning liquid; the spicy seasoning liquid comprises, by weight, 13-17 parts chili powder, 6-10 parts Sichuan pepper powder, 6-10 parts salt, 4-6 parts white sugar, 2-4 parts yeast extract, and 190-210 parts water. As an optional embodiment of the present invention, the spicy seasoning liquid comprises, by weight, 15 parts chili powder, 8 parts Sichuan pepper powder, 8 parts salt, 5 parts white sugar, 3 parts yeast extract, and 200 parts water. As an optional embodiment of the present invention, the seasoning impregnation method of the spicy seasoning liquid includes vacuum impregnation; the vacuum impregnation time can be 10 to 14 minutes, or 12 minutes, and the vacuum impregnation pressure can be -0.09 MPa. As an optional embodiment of the present invention, the seasoning liquid includes a five-spice seasoning liquid; the composition of the five-spice seasoning liquid includes, by weight: 10 to 14 parts five-spice powder, 4 to 6 parts cinnamon powder, 2 to 4 parts star anise powder, 5 to 7 parts salt, 3 to 5 parts rock sugar, and 170 to 190 parts water. As an optional embodiment of the present invention, the composition of the five-spice seasoning liquid includes, by weight: 12 parts five-spice powder, 5 parts cinnamon powder, 3 parts star anise powder, 6 parts salt, 4 parts rock sugar, and 180 parts water. As an optional embodiment of the present invention, the five-spice seasoning liquid seasoning impregnation method includes stirring and impregnating at normal pressure; the time of the stirring and impregnating at normal pressure can be 16 to 20 minutes, or 18 minutes; the rotation speed of the stirring and impregnating at normal pressure can be 25 to 35 rpm, or 30 rpm.

[0035] After the seasoning and dipping is completed, the present invention dries the cicada pupae. In the present invention, the drying includes a first-stage drying and a second-stage drying; the temperature of the first-stage drying can be 43-47°C, or 43, 44, 45, 46, or 47°C; the time of the first-stage drying can be 1.5-3.0 hours, or 1.5, 2.0, 2.5, or 3.0 hours; the temperature of the second-stage drying can be 48-52°C, or 50°C; the time of the second-stage drying can be 1.3-1.7 hours, or 1.5 hours. In the present invention, the first drying stage can form a crispy shell on the surface of the cicada pupae; the second drying stage can further reduce the moisture content of the cicada pupae and increase their crispness. The present invention uses a staged drying process during the preparation of cicada pupa snacks to precisely control temperature and retain nutrients: the first stage of low-temperature drying (43-47°C) avoids high-temperature damage to nutrients such as protein and amino acids (protein retention rate ≥92%), while the second stage of heating (48-52°C) only removes moisture. The entire low-temperature process improves the nutrient retention rate by more than 20% compared to traditional hot air drying (80°C). The staged gradient dehydration makes the cicada pupae uniformly brittle: the staged drying uses a gradient process of "surface shaping → internal dehydration" to reduce the internal moisture distribution error of the cicada pupae to ≤±2.5% (the traditional single-stage drying error is ≥±8%), completely solving the "hard outside, soft inside" problem. The brittleness meter test value fluctuates by only ±10N (the traditional process fluctuates by ±20-25N). The staged gradient dehydration also saves energy, reduces consumption, and improves efficiency: the temperature difference between the two stages (5-9°C) forms a heat conduction gradient, which reduces energy consumption by 30% compared to single high-temperature drying. At the same time, it avoids excessive protein denaturation caused by prolonged high temperature, ensuring a balance between product crispness and nutrition.

[0036] The preparation method provided by the invention can improve the flavor of cicada pupae and enhance the nutritional value of cicada pupae through infrared treatment, ultraviolet treatment, seasoning impregnation and staged drying.

[0037] The present invention provides an application of the preparation method described in the above technical solution in improving the quality of cicada pupae. As an optional embodiment of the present invention, the improving the quality of cicada pupae includes improving the sensory evaluation of cicada pupae and / or improving the nutritional value of cicada pupae.

[0038] In order to further illustrate the present invention, the technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0039] In the following technical solution, the method for detecting the permeability of the seasoning is: the permeability of the seasoning is detected after the seasoning is soaked, and the detection is carried out by high performance liquid chromatography (HPLC). The specific steps are: take the cicada pupae after the seasoning is soaked, take the surface and internal tissues respectively, grind them, extract them with methanol, pass them through a 0.45μm filter membrane, and analyze them.

[0040] Example 1

[0041] A method for preparing cicada pupa snacks, comprising the following steps:

[0042] Select fresh cicada pupae weighing ≤0.5g and ≤3cm in length, ensuring the pupae's epidermis is intact and undamaged. Rinse the pupae three times with running water, each rinse lasting 1 minute. Ultrasonic cleaning is then performed at 40kHz for 3 minutes, ensuring that surface impurities remain ≤0.1%.

[0043] The cleaned cicada pupae are activated with saline solution. The specific operation is as follows: the cicada pupae are added into saline solution and soaked for 10 minutes. The mass concentration of the salt in the saline solution is 4%, and 0.05% citric acid is added into the saline solution.

[0044] After the cicada pupae are activated by salt water, they are spread out and then treated with infrared rays. The thickness of the spread is 2 cm, the wavelength of the infrared rays is 780 μm, and the irradiation intensity is 35 mW / cm 2 , time 12 minutes.

[0045] After the infrared treatment, the pupae were treated with ultraviolet light. The wavelength of the ultraviolet light was 265nm and the intensity was 35mW / cm 2 , time 20 minutes.

[0046] The bacteria carried by cicada pupae were tested before and after infrared treatment. The results showed that the number of live bacteria carried by cicada pupae before infrared treatment was 8×10 3 CFU / g; after treatment with infrared and ultraviolet rays, the number of live bacteria carried by cicada pupae is less than 10 CFU / g.

[0047] After UV treatment, cicada pupae were impregnated with a seasoning solution consisting of 15g chili powder, 8g Sichuan pepper powder, 8g salt, 5g sugar, 3g yeast extract, and 200mL water. The pH of the solution was 4.8-5.2. The pupae were mixed with the seasoning solution at a mass-to-volume ratio of 1kg:200mL and then vacuum impregnated at -0.09MPa for 12 minutes. After the impregnation, the capsaicinoid distribution uniformity, i.e., the penetration rate of the chili powder, was tested.

[0048] Because capsaicin is the characteristic flavor component in chili powder, its distribution on the surface and inside of cicada pupae can directly reflect the penetration degree of chili powder in cicada pupae, so the uniformity of capsaicin distribution is used as an indicator to detect the permeability of chili powder. Detection method: adopt high performance liquid chromatography (HPLC) method to detect the distribution of seasoning on the surface and inside of cicada pupae, specifically comprising the following steps: take cicada pupae after seasoning immersion, take the surface layer and internal tissue respectively, grind and extract with methanol, pass through 0.45 μm filter membrane, and analyze by sample introduction. In embodiment 1, after the above method detection, the capsaicin content of the cicada pupae surface layer after vacuum impregnation is 0.36mg / g, and the capsaicin content of the internal layer is 0.34mg / g, and the difference between the surface layer and the internal content is ≤5%, indicating that chili powder penetrates evenly. The permeability of chili powder reaches 90%.

[0049] The calculation of 90% penetration of chili powder is based on the characteristic component capsaicin as an indicator, and is obtained through high performance liquid chromatography (HPLC) quantitative analysis, as follows:

[0050] Indicator selection: Capsaicin, the characteristic ingredient in chili powder, is used as the quantitative indicator because of its stable chemical properties and can be accurately detected by HPLC.

[0051] Calculation of the theoretical total capsaicin content: Given the initial capsaicin concentration in the seasoning solution (0.25 mg / mL as determined by HPLC), combined with the mass-to-volume ratio of cicada pupae to seasoning solution (1 kg:200 mL), the theoretical total capsaicin content is calculated as 200 mL × 0.25 mg / mL = 50 mg (i.e., the total amount of capsaicin in the seasoning solution that came into contact with the cicada pupae).

[0052] Determination of actual absorption amount: Take the immersed cicada pupae, and detect the surface layer (accounting for 30% of the total mass) and the internal layer (accounting for 70%): the capsaicin content in the surface layer is 0.36 mg / g, and the total amount is 300 g×0.36 mg / g=108 mg; the internal content is 0.34 mg / g, and the total amount is 700 g×0.34 mg / g=238 mg; the actual total absorption amount is 108+238=346 mg.

[0053] Permeability calculation: Permeability = (actual total amount absorbed / theoretical total amount of capsaicin) × 100% = (346 mg / 385 mg) × 100% ≈ 90% (Note: 385 mg is the maximum theoretical value of the seasoning solution that can be absorbed by cicada pupae, that is, the total amount of capsaicin in the seasoning solution. Since the seasoning solution is not completely absorbed, it is calculated based on this).

[0054] After the seasoning and impregnation are completed, the obtained cicada pupae are dried using a belt dryer. The pupae are spread to a thickness of 2 cm during drying, the wind speed during drying is 1.5 m / s, the mesh belt speed is 0.5 m / min, and the drying is divided into the first stage drying and the second stage drying. The temperature of the first stage drying is 45°C and the time is 2 hours. Drying is carried out until the moisture content is reduced to 20% to 25%, and a brittle shell is formed on the surface of the cicada pupae. The temperature of the second stage drying is 50°C and the time is 1.5 hours. Drying is carried out until the moisture content is reduced to 12% ± 1%. After drying is completed, a cicada pupa snack is obtained.

[0055] The cicada pupa snack prepared in this embodiment is spicy and crispy cicada pupae.

[0056] The prepared cicada pupa snacks were evaluated on moisture content, crispness and sensory properties.

[0057] The method for determining moisture content is: direct drying method (GB 5009.3-2016). Specific operation: Take 5g of crushed cicada pupa sample, place it in a constant temperature drying oven at 105℃ and dry it to constant weight, calculate the percentage of moisture mass loss to the initial mass of the sample, that is, moisture content = (initial mass - mass after constant weight) / initial mass × 100%. The brittleness detection method is: use texture analyzer (TPA mode) for detection. Specific parameters: The probe is a P / 25 cylindrical probe, the test speed is 1mm / s, the compression distance is 50% of the sample thickness, and the maximum force value (unit N) when the sample breaks is recorded. This force value is the brittleness value. The brittleness fluctuation value detection method is: The brittleness fluctuation value detection method is: Randomly select 10 cicada pupa samples from the same batch, and use the above-mentioned texture analyzer method to determine the brittleness value, calculate the standard deviation of the 10 data, and express the brittleness fluctuation value as "± standard deviation". The sensory evaluation standards are as follows: 10 professional judges are invited to score based on four aspects: crispness (out of 10 points), flavor (out of 10 points), color (out of 5 points), and taste (out of 5 points), with a total score of 30 points.

[0058] The results showed that the moisture content of the cicada pupa snack prepared in this embodiment was 11.8%, and the brittleness was 205N (the brittleness meter test value fluctuated by ±10N). The total sensory evaluation score of this sample was 26.4 points. The scores of each dimension of the sensory evaluation of this sample are as follows: crispness 8.8 points (because the crispness is stable and moderate, and the fracture is clear); flavor 9.0 points (out of 10 points, the spicy taste penetrates evenly, and there is no green and astringent taste); color 4.3 points (natural light brown, without burnt spots); taste 4.3 points (crisp but not hard when put into the mouth, and there is no residue when chewing). The sum of the four scores is 8.8+9.0+4.3+4.3=26.4 points.

[0059] The crispness consistency, protein retention rate, fat content and protein cross-linking degree of the cicada pupa snack prepared in this example were further tested.

[0060] The method for testing crispness consistency is: the same as the crispness fluctuation value detection method, by measuring the crispness values ​​of 10 samples in the same batch, calculating 1 / 2 of the difference between the maximum and minimum values, that is, (maximum value - minimum value) / 2, and the result is expressed as "±XN".

[0061] The protein retention rate was determined using the Kjeldahl method (GB 5009.5-2016). The protein content of the raw and finished cicada pupae was determined using the formula: protein retention rate = (protein content of finished product / protein content of raw material) × 100%.

[0062] The oil and fat detection method is the Soxhlet extraction method (GB 5009.6-2016). Using ether as the extractant, extract the oil and fat from the sample and calculate the percentage of oil and fat to sample weight, i.e., oil content = (oil and fat weight / sample weight) × 100%.

[0063] Protein cross-linking was determined using sodium dodecyl sulfate (SDS) extraction. Samples were ground and extracted with 1% SDS (containing 0.1 M Tris-HCl buffer, pH 8.0) in an 80°C water bath for 30 min. Following centrifugation, the protein content of the supernatant (soluble protein) and precipitate (cross-linked protein) was determined using the Kjeldahl method. Protein cross-linking degree = (protein content in precipitate / total protein content) × 100%.

[0064] The method for detecting the internal moisture distribution error is as follows: take a single cicada pupa sample, take the surface layer (epidermis and 0.2 cm below the skin) and the interior (remaining deep tissue) respectively, use the direct drying method to determine the moisture content of the two, and calculate the error value = |surface moisture content - internal moisture content| / ((surface moisture content + internal moisture content) / 2)×100%; randomly select 10 samples and take the average value as the final internal moisture distribution error.

[0065] The results showed that the crispness consistency of cicada pupa snacks was ±10N, the protein retention rate was ≥92%, the seasoning uniformity, i.e. the difference between the surface and the interior was ≤5%, and the oil content was ≤2%.

[0066] The resulting cicada pupa snack has a protein content of 78.5%, a protein cross-linking degree of 35.4%, an 18% increase, and an internal moisture distribution error of ±2.5%. Testing of the finished product revealed a viable microbial count of less than 10 CFU / g, meeting food safety standards.

[0067] Example 2

[0068] A method for preparing cicada pupa snacks, comprising the following steps:

[0069] Take fresh cicada pupae weighing ≤0.5g and ≤3cm in length, ensuring the skin is intact and undamaged. Rinse the pupae three times with running water, each rinse lasting 1 minute. Ultrasonic cleaning is then performed at 40kHz for 3 minutes, ensuring that surface impurities remain ≤0.1%.

[0070] The cleaned cicada pupae are activated with saline solution. The specific operation is as follows: the cicada pupae are added into saline solution and soaked for 10 minutes. The mass concentration of the salt in the saline solution is 4%, and 0.05% citric acid is added into the saline solution.

[0071] After the cicada pupae are activated by salt water, they are spread out and then treated with infrared rays. The thickness of the spread is 2 cm, the wavelength of the infrared rays is 780 μm, and the irradiation intensity is 35 mW / cm 2 , time 10 minutes.

[0072] After the infrared treatment, the pupae were treated with ultraviolet light. The wavelength of the ultraviolet light was 265nm and the intensity was 35mW / cm 2 , time 15 minutes.

[0073] After UV treatment, cicada pupae were seasoned and impregnated with a seasoning solution consisting of 12g five-spice powder, 5g cinnamon powder, 3g star anise powder, 6g salt, 4g rock sugar, and 180mL of water. The pH of the seasoning solution was 5.5-6.0. The seasoning impregnation method involved mixing the cicada pupae with the seasoning solution at a mass-to-volume ratio of 1kg:180mL. The impregnation was performed under normal pressure for 18 minutes with stirring at 30 rpm. After the seasoning impregnation was completed, the five-spice powder penetration rate was measured. The five-spice powder penetration rate was determined by GC-MS analysis of the eugenol content, and the results showed that the five-spice powder had a penetration rate of 88%.

[0074] GC-MS detection showed that after the normal pressure stirring and impregnation in Example 2, the content of eugenol (a characteristic component of five-spice powder) in the surface layer of cicada pupae was 0.23 mg / g, and the content of eugenol in the interior was 0.21 mg / g, with a content difference of about 9.5% between the surface layer and the interior.

[0075] After the seasoning and impregnation process, the resulting cicada pupae were dried to a thickness of 2 cm using a belt dryer. The drying process was performed at a wind speed of 1.5 m / s and a mesh belt speed of 0.5 m / min. The drying process consisted of a first drying stage and a second drying stage. The first drying stage was performed at 40°C for 3 hours. The second drying stage was performed at 50°C for 1 hour. After drying, the cicada pupae snack was obtained.

[0076] The cicada pupa snack prepared in this embodiment is crispy cicada pupae with a five-spice flavor.

[0077] The prepared cicada pupa snacks were evaluated for moisture content, crispness, and sensory evaluation using the same sensory evaluation criteria as in Example 1.

[0078] The results showed that the moisture content of the finished cicada pupa snack was 12.5%, and the crispness was 190N (the brittleness meter test value fluctuated by ±10N), which is suitable for elderly consumers to chew.

[0079] The sensory evaluation results of this embodiment are as follows: the total sensory evaluation score of this sample is 25.7 points.

[0080] The sample's sensory evaluation scores for each dimension are as follows: crispness 8.5 (crispness 190N with minimal fluctuation, soft texture, suitable for chewing by elderly consumers); flavor 8.8 (harmonious five-spice flavors, with even penetration of cinnamon and star anise); color 4.2 (light brown, uniform color without burn marks); and taste 4.2 (moderate crispness, no hardness or residue, and easy chewing). The total score for these four dimensions is 8.5 + 8.8 + 4.2 + 4.2 = 25.7 points.

[0081] After testing, the number of viable microorganisms is less than 10 CFU / g, which meets the food safety standards.

[0082] The crispness consistency, protein retention rate, seasoning uniformity, fat content and protein cross-linking degree of the cicada pupa snack prepared in this example were further tested. The method was the same as that in Example 1.

[0083] The results showed that the crispness consistency of cicada pupa snacks was ±10N, the protein retention rate was ≥92%, the seasoning uniformity, i.e. the difference between the surface and the interior was ≤5%, and the oil content was ≤2%.

[0084] The protein content of the prepared cicada pupa snack is 76.8%, the protein cross-linking degree is 34.8%, which is increased by 16%, and the internal moisture distribution error is ±2.8%.

[0085] Comparative Example 1

[0086] A method for preparing a cicada pupa snack comprises the same steps as in Example 1, with the only difference being that the seasoning and impregnation process is performed under normal pressure for 36 minutes, with stirring at 30 rpm. After the seasoning and impregnation process is completed, the capsaicinoid distribution uniformity, i.e., the permeability of the chili powder, is tested. The results show that the permeability of the chili powder during the seasoning and impregnation process using this method is 30%.

[0087] The detection method of capsaicin was the same as that in Example 1. After detection by high performance liquid chromatography (HPLC), in Comparative Example 1, after normal pressure immersion, the capsaicin content of the surface layer of cicada pupae was 0.45 mg / g, while the capsaicin content inside was only 0.15 mg / g. The content on the surface was three times that of the inside, and the difference was significant, indicating that the seasoning was unevenly penetrated under normal pressure immersion.

[0088] Comparative Example 2

[0089] A method for preparing cicada pupa snacks, comprising the following steps:

[0090] Select fresh cicada pupae weighing ≤0.5g and ≤3cm in length, ensuring the pupae's epidermis is intact and undamaged. Rinse the pupae three times with running water, each rinse lasting 1 minute. Ultrasonic cleaning is then performed at 40kHz for 3 minutes, ensuring that surface impurities remain ≤0.1%.

[0091] The cleaned cicada pupae were added to a 5% saline solution (without citric acid) and soaked at room temperature for 30 minutes without stirring. The pupae were taken out and the surface moisture was drained to complete the pickling.

[0092] Spread the pickled cicada pupae flat on a tray, place them in a hot air drying oven, and dry them at 80°C for 6 hours.

[0093] The prepared cicada pupae are hard on the outside and soft on the inside, with unstable brittleness, and the brittleness test value fluctuates by ±20N. The seasoning penetration is uneven, and the seasoning content on the surface is 2 to 3 times that of the inside.

[0094] The microorganisms in the prepared cicada pupae were detected, and the results showed that the number of viable microorganisms was 5×10 3 CFU / g, protein retention rate 75%.

[0095] The cicada pupae prepared in Comparative Example 2 were subjected to a sensory evaluation, and the sensory evaluation criteria were the same as those in Example 1. The total score of the sensory evaluation was 18 points (out of 30 points, with a lower score due to the hard outside and soft inside and uneven seasoning).

[0096] The sample received the following sensory evaluation scores: Crispness 5.0 (hard on the outside, soft on the inside, large fluctuations in crispness, and uneven snapping); Flavor 5.5 (uneven seasoning penetration, too salty on the outside, bland on the inside); Color 3.0 (dark brown with slight burn marks in some areas); and Taste 3.5 (hard on the outside, soft on the inside, with a noticeable crumbly feel when chewed). The total of these four scores is 5.0 + 5.5 + 3.0 + 3.5 = 17 points, giving the overall evaluation of "hard on the outside, soft on the inside, and uneven seasoning."

[0097] The protein content, protein cross-linking degree and internal moisture distribution error of the cicada pupae prepared in Comparative Example 2 were tested, and the results showed that the protein content of the prepared cicada pupa snack was 65.2%, the protein cross-linking degree was 31.5%, an increase of 5%, and the internal moisture distribution error was ±10%.

[0098] Comparative Example 3

[0099] A method for preparing cicada pupa snacks, comprising the following steps:

[0100] Select fresh cicada pupae weighing ≤0.5g and ≤3cm in length, ensuring the pupae's epidermis is intact and undamaged. Rinse the pupae three times with running water, each rinse lasting 1 minute. Ultrasonic cleaning is then performed at 40kHz for 3 minutes, ensuring that surface impurities remain ≤0.1%.

[0101] The cleaned cicada pupae were added to a 5% saline solution (containing only salt without citric acid) and soaked at room temperature for 20 minutes without stirring. After being taken out, the surface moisture was drained to complete the pickling.

[0102] Fry the cicada pupae in oil at 180°C to 200°C for 15 to 20 minutes, remove them from the oil, and then season them.

[0103] The protein denaturation rate in cicada pupa snacks is ≥40%, the protein retention rate is 60%-70%, the amino acid loss is ≥25%, and the oil absorption rate is ≥15%, which is about 15%-20%. The frizzometer test value fluctuates by ±25N, and the seasoning uniformity difference, that is, the difference between the surface and the interior is 20%-30%, which does not meet the needs of modern healthy snacks.

[0104] The prepared cicada pupa snack has a protein content of 55% to 60%, a protein cross-linking degree increased by about 5%, and an internal moisture distribution error of ±15%.

[0105] Sensory evaluation: The total score is 12 to 16 points (out of 30 points), including 4 to 5 points for crispness (the surface is too hard and the inside is soft), 3 to 4 points for flavor (the oily taste covers the original aroma), 2 to 3 points for color (uneven browning), and 3 to 4 points for taste (obvious greasy feeling).

[0106] Comparative Example 4

[0107] A method for preparing a cicada pupa snack comprises the same steps as in Example 1, with the only difference being that microwave sterilization is used instead of ultraviolet sterilization. The microwave sterilization method comprises microwave treatment at a power of 700-800W and a frequency of 2450MHz for 3-4 minutes.

[0108] The total number of colonies of the prepared cicada pupa snacks is 10 2CFU / g, which did not reach the bactericidal effect of the present invention, and the cicada pupa was yellowish in color and had a brittleness of 170N.

[0109] The protein content of the prepared cicada pupa snack is 70% to 72%, the protein cross-linking degree is increased by about 10%, and the internal moisture distribution error is ±7% (uneven microwave heating leads to inconsistent moisture removal).

[0110] The total score is 18 to 22 points (out of 30 points), including 5 to 6 points for crispness (crispyness 170N, lower than 205N of the embodiment), 5 to 6 points for flavor (microwave causes a slight burnt smell), 3 to 4 points for color (yellowish and dark), and 5 to 6 points for taste (poor crispness consistency).

[0111] Crispness consistency: ±18N (uneven microwave heating causes crispness fluctuations greater than ±10N in the example);

[0112] Seasoning uniformity: The difference between the surface and the interior is 15% to 20%. Microwave treatment does not improve the permeability of the epidermis, and the seasoning penetration effect is worse than that of ultraviolet treatment.

[0113] Grease content: ≤2% (same as Example 1, without frying step).

[0114] Comparative Example 5

[0115] A method for preparing a cicada pupa snack comprises the same steps as in Example 1, with the only difference being that hot air drying is used instead of infrared treatment, and the hot air drying method comprises: hot air drying at a temperature of 60° C. to 65° C. and a wind speed of 1.0 to 1.2 m / s for 25 to 30 min.

[0116] The prepared cicada pupa snack has an internal moisture content reduced to 68%, a crispness of 160N, and a moisture distribution error of ±8%.

[0117] The prepared cicada pupa snack has a protein content of 70% to 73%, and the protein cross-linking degree is increased by 12%.

[0118] Sensory evaluation: Total score 20-24 points (out of 30 points), including 6-7 points for crispness, 6-7 points for flavor (slightly dry and hard taste due to hot air), 5-6 points for color (light color), and 3-4 points for taste (poor crispness consistency);

[0119] Crispness consistency: ±15N (the temperature gradient of hot air drying causes the crispness fluctuation to be greater than ±10N in the embodiment);

[0120] Seasoning uniformity: 10% to 12% difference between the surface and the interior (hot air did not improve the epidermal structure, and the permeability was lower than that of the infrared + ultraviolet treatment group);

[0121] Grease content: ≤2%.

[0122] Comparative Example 6

[0123] A method for preparing a cicada pupa snack comprises the same steps as in Example 1, with the only difference being that a single-stage drying is adopted after the seasoning impregnation is completed. The specific conditions are: a belt dryer is used, a paving thickness of 2 cm, a wind speed of 1.5 m / s, a mesh belt speed of 0.5 m / min, a drying temperature of 45° C., and a drying time of 4.5 h.

[0124] Test results:

[0125] Moisture content: 12.0%;

[0126] Brittleness: 160N, the brittleness meter test value fluctuation is ±15N;

[0127] Internal moisture distribution error: ±6.2%;

[0128] Protein retention: 91.5%;

[0129] Sensory evaluation: The total score was 22.0 points, including 7.0 points for crispness (the surface crispness is not obvious, and the cracking feeling is weak), 8.2 points for flavor (the seasoning penetration is slightly poor), 4.0 points for color, and 2.8 points for taste (the interior is soft and has a sticky feeling when chewed).

[0130] Defect analysis: Single 45℃ drying has no heating stage, so the crispy shell cannot form quickly on the surface, and the internal moisture is removed slowly and unevenly, resulting in low crispness and poor consistency. The extended drying time also causes a slight loss of some nutrients.

[0131] Comparative Example 7

[0132] A method for preparing a cicada pupa snack comprises the same steps as in Example 1, with the only difference being that a single-stage drying is adopted after the seasoning impregnation is completed. The specific conditions are: a belt dryer is used, a paving thickness of 2 cm, a wind speed of 1.5 m / s, a mesh belt speed of 0.5 m / min, a drying temperature of 50° C., and a drying time of 3.0 h.

[0133] Test results:

[0134] Moisture content: 11.9%;

[0135] Brittleness: 180N, the brittleness meter test value fluctuates ±18N;

[0136] Internal moisture distribution error: ±8.0%;

[0137] Protein retention: 85.0%;

[0138] Sensory evaluation: Total score: 21.0, including 6.5 points for crispness (excessively dry and hard on the outside, soft on the inside), 7.8 points for flavor (high temperature causes some spices to evaporate, making the flavor fade), 3.5 points for color (some burnt spots), and 3.2 points for texture (hard on the outside, soft on the inside, difficult to chew).

[0139] Defect analysis: Single 50℃ drying causes the surface moisture to evaporate quickly due to the continuously high temperature, forming a hard shell, which hinders the removal of internal moisture, resulting in "hard outside and soft inside" and large fluctuations in crispness; high temperature also intensifies protein denaturation, reduces nutrient retention, and causes flavor substances to be lost due to long-term volatilization at high temperature.

[0140] In summary, by comparing Example 1 (stage drying) with Comparative Examples 6 and 7 (single stage drying), it can be seen that stage drying can significantly reduce the internal moisture distribution error, reduce crispness fluctuations, and increase protein retention through the gradient process of "low temperature setting → heating to crispen". This fully demonstrates the advantages of stage drying in uniform crispening, nutrient retention and flavor stability.

[0141] Although the above embodiment provides a detailed description of the present invention, it is only a part of the embodiments of the present invention, not all of the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the scope of protection of the present invention.

Claims

1. A method for preparing cicada pupa snacks, characterized in that: The following steps are involved: adding cicada pupae into salt water and soaking them to obtain salt water-activated cicada pupae; The salt-water activated cicada pupae were subjected to infrared treatment; The infrared-treated cicada pupae were then treated with ultraviolet light; The cicada pupae treated with ultraviolet light are seasoned and impregnated and then dried to obtain cicada pupae snacks; The drying includes first-stage drying and second-stage drying; the drying temperature of the first stage is 43-47° C.; the drying time of the first stage is 1.5-3.0 hours; the drying temperature of the second stage is 48-52° C.; the drying time of the second stage is 1.3-1.7 hours.

2. The preparation method according to claim 1, characterized in that The wavelength of the infrared treatment is 760-800 μm; the irradiation intensity of the infrared treatment is 30-40 mW / cm 2 The infrared treatment time is 10 to 14 minutes; the wavelength of the ultraviolet treatment is 265 to 270 nm; the irradiation intensity of the ultraviolet treatment is 30 to 40 mW / cm 2 ; The ultraviolet treatment time is 18 to 22 minutes.

3. The preparation method according to claim 1, characterized in that: The mass concentration of common salt in the brine is 3% to 5%, and the mass concentration of citric acid is 0.04% to 0.06%. The soaking time is 8 to 12 minutes.

4. The preparation method according to claim 1, characterized in that The seasoning impregnation method comprises mixing cicada pupae with a seasoning liquid for impregnation; the mass volume ratio of the cicada pupae to the seasoning liquid is 1 kg:180-200 mL.

5. The preparation method according to claim 4, characterized in that: The seasoning liquid includes a spicy seasoning liquid; calculated by weight, the spicy seasoning liquid comprises: 13 to 17 parts of chili powder, 6 to 10 parts of pepper powder, 6 to 10 parts of table salt, 4 to 6 parts of white sugar, 2 to 4 parts of yeast extract and 190 to 210 parts of water.

6. The preparation method according to claim 5, characterized in that: The seasoning impregnation method of the spicy seasoning liquid includes vacuum impregnation; the time of the vacuum impregnation is 10 to 14 minutes.

7. The preparation method according to claim 4, characterized in that: The seasoning liquid includes a five-spice seasoning liquid; calculated by mass, the five-spice seasoning liquid comprises: 10 to 14 parts of five-spice powder, 4 to 6 parts of cinnamon powder, 2 to 4 parts of star anise powder, 5 to 7 parts of salt, 3 to 5 parts of rock sugar and 170 to 190 parts of water.

8. The preparation method according to claim 7, characterized in that: The five-spice seasoning liquid seasoning impregnation method comprises stirring and impregnating at normal pressure; the time of stirring and impregnating at normal pressure is 16 to 20 minutes; and the rotation speed of stirring and impregnating at normal pressure is 25 to 35 rpm.

9. Use of the preparation method according to any one of claims 1 to 8 in improving the quality of cicada pupae.

10. The use according to claim 9, characterized in that: Improving the quality of cicada pupae includes improving the flavor of cicada pupae and / or increasing the nutritional value of cicada pupae.