A method for directional charring of chilli based on structure regulation drying and application thereof in composite seasoning

Abstract

This invention belongs to the field of food processing, specifically relating to a method for directional caramelization of chili peppers based on structure-controlled drying and its application in compound seasonings. The processing technology provided by this invention, under the action of vacuum pulses, causes the cells inside the chili pepper tissue to undergo periodic expansion and contraction, thereby forming a microporous structure and microchannel structure. This porous structure can significantly improve the adsorption and diffusion efficiency of flavor substances in the smoke during the smoking process. During the smoking stage, volatile flavor substances in the smoke are adsorbed onto the surface of the chili pepper; during the diffusion stage, the flavor components of the smoke migrate into the interior of the chili pepper tissue under the action of a concentration gradient, thereby improving the uniformity of the distribution of smoked flavor within the chili pepper.

Description

Technical Field

[0001] This invention belongs to the field of food processing, specifically relating to a method for directional caramelization of chili peppers based on structure-controlled drying and its application in compound seasonings. Background Technology

[0002] chili( Capsicum spp. Chili peppers are an important and widely used spice ingredient globally. Their main flavor comes from capsaicinoids, volatile aroma components, and various secondary metabolites. Traditional chili processing typically involves sun-drying or hot-air drying to produce dried chilies, which are then further ground into chili powder or chili flakes. However, this method primarily focuses on moisture removal, offering limited control over the internal structure and flavor profile of the chili pepper. The resulting products are often characterized by a single spiciness and chili aroma, resulting in a relatively simple flavor profile. Existing technologies also include methods that utilize smoking to impart a smoky flavor to chilies.

[0003] US Patent 20210368813A1 discloses a method for preparing compound flavorings by smoking dried chili peppers with hardwood. This method typically uses already dried chili peppers as raw material and imparts a smoky flavor through continuous smoking. However, due to the relatively dense structure of dried chili peppers, the volatile flavor compounds in the smoke mainly deposit on the surface of the peppers, making it difficult to effectively penetrate into the internal structure. This results in uneven distribution of the smoky flavor and limited flavor profile. Furthermore, continuous smoking can easily lead to over-smoking of the surface or the formation of bitterness, which is detrimental to obtaining a stable and high-quality flavor structure. It also makes stable industrial production and standardized quality control difficult to achieve.

[0004] Therefore, developing a chili seasoning that uses fresh chili peppers as raw material and rationally controls processing steps such as drying, smoking, and charring to allow the smoky flavor to penetrate deep into the chili pepper tissue while simultaneously building a stable charred flavor layer on the surface of the chili pepper, thus forming a complex flavor structure of smoky, charred, and chili pepper aroma, is of great significance for improving product flavor quality and achieving large-scale industrial application. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a method for directional charring of chili peppers based on structure-controlled drying. This method uses fresh chili peppers as raw materials and adjusts the chili pepper tissue structure through structure-controlled drying technology to improve the penetration ability of smoky flavor substances. Subsequently, the volatile flavor compounds generated by the thermal decomposition of wood are uniformly introduced into the interior of the chili pepper tissue through a smoking aroma process. Furthermore, a caramel flavor layer is constructed through surface directional charring technology, thereby obtaining a chili pepper seasoning with a complex flavor characteristics of smoky aroma, caramel aroma and chili pepper aroma.

[0006] The present invention further provides a chili pepper with a complex flavor of smoky aroma, caramel aroma and chili aroma prepared by the above method.

[0007] Another objective of this invention is to provide a compound seasoning containing the aforementioned chili peppers, which is suitable for sauerkraut soup, stews, barbecue seasoning, and the development of various compound seasonings.

[0008] The technical solution adopted by the present invention to achieve the above objectives is as follows: This invention provides a method for directional caramelization of chili peppers based on structure-controlled drying, comprising the following steps: (1) Use fresh red chili peppers as raw materials, spray the surface of the chili peppers with calcium citrate solution, and let them dry; (2) Place the chili peppers in a pulse vacuum drying equipment for vacuum hot air drying; (3) The chili peppers that have undergone structural regulation and drying are transferred to a smoking equipment for pulsed smoke diffusion treatment; (4) After the smoking treatment is completed, the flavor precursor solution is sprayed evenly on the surface of the chili peppers, and then the chili peppers are subjected to electromagnetic instantaneous caramelization treatment. After the treatment is completed, the chili peppers are crushed to obtain chili powder that combines smoking and roasting.

[0009] Preferably, in step (1), the mass concentration of the calcium citrate aqueous solution is 15% to 18%.

[0010] Preferably, in step (2), the vacuum hot air drying process is carried out in a pulse vacuum drying device with the following parameters: hot air temperature 55-70 ℃, vacuum degree −60-−90 kPa, vacuum pulse cycle 5-15 min, and drying until the moisture content of the chili peppers is 25%-35%.

[0011] Preferably, in step (3), the pulse fumigation and diffusion treatment alternates between a fumigation stage and a diffusion stage, with the fumigation stage lasting 8 to 12 minutes and the diffusion stage lasting 15 to 25 minutes, for a total of 15 to 30 cycles, and the fumigation temperature being 80 to 100 ℃.

[0012] Preferably, in step (3), the smoke comes from the oxygen-controlled pyrolysis of hardwood materials during the smoking process; the smoke source is one or more of oak, birch, apple and cherry wood.

[0013] Preferably, in step (3), the smoke source is composed of 30% to 60% oak, 10% to 30% birch, 10% to 30% apple wood, and 5% to 20% cherry wood; the oxygen-controlled pyrolysis has a pyrolysis temperature of 320 to 450 ℃ and an oxygen concentration of 2% to 8%.

[0014] Preferably, in step (4), the flavor precursor solution is composed of the following raw materials in percentage: 0.5-3% reducing sugar, 0.2-1.5% amino acids, 0.05-0.3% guar gum, and the balance being water; the reducing sugar is one or more of glucose, fructose, and maltose; the amino acid is one or more of glycine, alanine, and cysteine.

[0015] Preferably, in step (4), the parameters of the electromagnetic instantaneous coking treatment are: surface temperature 320~450 ℃ and treatment time 5~30 s.

[0016] The present invention also provides a chili pepper with a complex flavor of smoky aroma, caramel aroma and chili aroma prepared by the above method.

[0017] The present invention further provides a compound seasoning containing the above-mentioned chili peppers, the raw material composition being: 40% to 80% chili powder, 10% to 30% salt, 2% to 10% garlic powder, 2% to 8% onion powder, 1% to 5% black pepper, 1% to 6% cumin, 0.5% to 3% Sichuan peppercorns, and 0.5% to 3% coriander seed powder.

[0018] The processing technology provided by this invention involves the periodic expansion and contraction of cells within the chili pepper tissue under vacuum pulse action, thereby forming a microporous and microchannel structure. This porous structure significantly improves the adsorption and diffusion efficiency of flavor compounds in the smoke during the smoking process. During the smoking stage, volatile flavor compounds in the smoke are adsorbed onto the surface of the chili pepper; during the diffusion stage, flavor components migrate into the interior of the chili pepper tissue under the influence of a concentration gradient, thus improving the uniformity of the smoked flavor distribution within the chili pepper.

[0019] The chili pepper varieties used in this invention include long chili peppers, horn chili peppers, or bird's eye chili peppers.

[0020] Compared with the prior art, the present invention has the following advantages: (1) The present invention forms a porous structure by pulsed vacuum hot air drying, which improves the penetration ability of smoked flavor; and the pulsed smoked diffusion treatment can make the distribution of smoke flavor substances in the chili tissue more uniform. (2) Based on the surface flavor directional charring technology, the present invention can generate char volatiles in a directional manner, thereby improving the flavor level; the product has a complex flavor structure of tobacco aroma, char aroma and chili aroma. Detailed Implementation

[0021] The technical solution of the present invention will be further explained and described below through specific embodiments.

[0022] Example 1 (1) Raw material preparation Select mature, fresh long peppers as raw materials, and spray the surface evenly with a 15% calcium citrate aqueous solution. (2) Pulse vacuum-hot air synergistic drying (structure-controlled drying) Chili peppers were placed in a pulsed vacuum drying apparatus for vacuum-hot air synergistic drying. The drying conditions were as follows: hot air temperature 55–70 °C, vacuum degree −60–−90 kPa, vacuum pulse cycle 10 min, drying time 6 hours, until the chili pepper moisture content reached 25%. Under the action of the vacuum pulse, the cells inside the chili pepper tissue underwent periodic expansion and contraction, thereby forming a microporous structure and microchannel structure. This porous structure can significantly improve the adsorption and diffusion efficiency of flavor substances in the smoke during the smoking process.

[0023] (3) Pulse smoke diffusion treatment The chili peppers, after undergoing structural regulation and drying, were transferred to a smoking equipment for pulsed smoking and diffusion treatment. The smoking process alternated between a smoking stage and a diffusion stage: the smoking stage lasted 12 minutes; the diffusion stage lasted 20 minutes, with 15 cycles performed. The smoking temperature was 80~100 ℃.

[0024] During the smoking stage, volatile flavor compounds in the smoke are adsorbed onto the surface of the chili peppers; during the diffusion stage, the flavor components of the smoke migrate into the interior of the chili pepper tissue under the influence of the concentration gradient, thereby improving the uniformity of the distribution of the smoked flavor inside the chili pepper.

[0025] (4) Oxygen-controlled pyrolysis fumigation technology (smoke source control) During the smoking process, the smoke originates from the controlled-oxygen pyrolysis of hardwood materials. The preferred smoke source is one or more of the following woods: oak, birch, apple, and cherry. The preferred mass ratio is: oak 50%, birch 30%, apple 10%, and cherry 10%. The pyrolysis temperature is 320–450 °C, and the oxygen concentration is 8%.

[0026] Under these conditions, the wood undergoes a thermal decomposition reaction, producing a variety of smoky flavor compounds, including phenolic compounds, aldehydes, ketones, and furans. Among these, phenolic substances can interact weakly with lipids and proteins in the chili pepper tissue, thereby improving the stability of the smoky flavor.

[0027] (5) Surface flavor-oriented coking treatment After smoking, the chili peppers undergo surface-oriented charring treatment to enhance their flavor. First, a small amount of flavor precursor solution (1% glucose, 0.5% glycine, 0.1% guar gum, and the remainder water) is sprayed onto the chili pepper surface; spray volume: 2.0% (mass ratio). Subsequently, the chili peppers undergo electromagnetic instantaneous charring treatment, with heating methods including infrared radiation heating, microwave-assisted infrared heating, and medium-wave or far-infrared radiation heating. The treatment conditions are: surface temperature 320–450 °C, treatment time 5–30 s. Under these conditions, a rapid Maillard reaction and mild charring reaction occur on the surface of the chili peppers, generating volatile compounds such as pyrazines, furans, and pyrroles, thus forming a typical charred flavor.

[0028] Since charring mainly occurs on the surface of the chili pepper, while the interior retains its smoky structure, a layered flavor structure is formed, consisting of a charred layer, a smoked layer, and a chili pepper tissue layer.

[0029] (6) Crushing and compounding The smoked and roasted chilies are then pulverized.

[0030] Comparative Example 1 (Drying without Structure Control) The difference compared to Example 1 is that step (2) uses conventional hot air drying at a temperature of 60 ℃. The time was 6 hours, with no vacuum pulse, and the remaining steps were the same.

[0031] Comparative Example 2 (No Pulse Smoke Diffusion) Compared with Example 1, the difference is that step (3) uses continuous fumigation at a temperature of 90 °C for 10 h, without alternating fumigation / diffusion, while the other steps are the same.

[0032] Comparative Example 3 (Non-directional coking) Compared with Example 1, the difference is that step (5) is changed to: flavorless precursor spraying, baking with ordinary hot air (250 ℃, 2 min), and the rest of the steps are the same.

[0033] Comparative Example 4 (Adjusted precursor spray composition) Compared with Example 1, the difference is that step (5) is changed to: the flavor precursor spray composition is: 1% glucose, 0.5% glycine and the remainder water, and the rest of the steps are the same.

[0034] Example 1 The examples and comparative examples were tested, and the main test indicators included total phenolic (fumigation phenol) content, pyrazine compounds, and sensory evaluation. The specific test methods are as follows: Phenolic (fumigated phenol) content: The volatile phenolic compounds in the sample were qualitatively and quantitatively analyzed by gas chromatography-mass spectrometry (GC-MS), with guaiacol as the representative compound for quantification.

[0035] Pyrazine compounds: The content of volatile pyrazine compounds was analyzed by GC-MS, with 2,5-dimethylpyrazine as a representative for quantification.

[0036] Sensory evaluation: A 10-person training evaluation team evaluated the smoky aroma (0–10), caramel aroma (0–10), and flavor harmony (0–10).

[0037] Experimental results show that, compared with Comparative Example 1, the present invention, through pulsed vacuum drying to form a porous structure, increases the content of smoky phenolic substances by approximately 40%, indicating that structural regulation significantly enhances the penetration ability of smoky flavor; compared with Comparative Example 2, the present invention employs pulsed smoke diffusion technology, resulting in a more uniform distribution of smoky flavor and a significant increase in total phenolic content; compared with Comparative Example 3, the present invention, through flavor precursor enhancement and electromagnetic instantaneous charring treatment, increases the content of pyrazine compounds by more than two times, significantly enhancing the caramel aroma; compared with Comparative Example 4, the present invention improves the overall flavor harmony. Sensory evaluation results show that the chili peppers prepared by the present invention are significantly superior to the comparative examples in terms of smoky aroma, caramel aroma, and overall flavor harmony. Experimental results indicate that there is a significant synergistic effect among the various technical steps of the present invention.

[0038] Example 2 The chili peppers prepared in Example 1 were used to make a compound seasoning. The specific raw material composition was as follows: 63% chili powder, 10% salt, 10% garlic powder, 8% onion powder, 1% black pepper, 4% cumin, 2% Sichuan pepper, and 2% coriander seed powder.

[0039] A control group was set up, and the chili powder in the control group was made from the chili prepared in Comparative Example 3.

[0040] Accelerated storage experiments were conducted on the compound seasoning and the seasoning powder prepared from the control group: storage at 37℃ and 60% RH for 1 month. The characteristic compounds of pyrazine caramel aroma were detected, and the content of volatile pyrazine compounds was analyzed by GC-MS. Specific detection conditions were: column: DB-5, HP-5MS; temperature program: 40℃ for 3 min → 5℃ / min to 250℃; carrier gas: He; qualitative analysis: NIST library comparison. The relative content was represented by the sum of the peak areas of the caramel aroma markers, and the caramel aroma retention rate was calculated.

[0041] ; In the formula, ∑A 前 : Initial total peak area of ​​caramel compounds; ∑A 后Total peak area after storage. See Table 2 for specific results.

[0042] Table 2

Claims

1. A method for directional caramelization of chili peppers based on structure-controlled drying, characterized in that, Includes the following steps: (1) Use fresh red chili peppers as raw materials, spray the surface of the chili peppers with calcium citrate solution, and let them dry; (2) Place the chili peppers in a pulse vacuum drying equipment for vacuum hot air drying; (3) The chili peppers that have undergone structural regulation and drying are transferred to a smoking equipment for pulsed smoke diffusion treatment; (4) After the smoking treatment is completed, the flavor precursor solution is sprayed evenly on the surface of the chili peppers, and then the chili peppers are subjected to electromagnetic instantaneous caramelization treatment. After the treatment is completed, the chili peppers are crushed to obtain chili powder that combines smoking and roasting.

2. The method for directional caramelization of chili peppers according to claim 1, characterized in that, In step (1), the mass concentration of the calcium citrate aqueous solution is 15% to 18%.

3. The method for directional caramelization of chili peppers according to claim 1 or 2, characterized in that, In step (2), the vacuum hot air drying process is carried out in a pulse vacuum drying device with the following parameters: hot air temperature 55-70 ℃, vacuum degree −60-−90 kPa, vacuum pulse cycle 5-15 min, and drying until the moisture content of the chili peppers is 25%-35%.

4. The method for directional caramelization of chili peppers according to claim 1, characterized in that, In step (3), the pulse fumigation and diffusion treatment is carried out alternately in the fumigation stage and the diffusion stage. The fumigation stage lasts for 8 to 12 minutes, and the diffusion stage lasts for 15 to 25 minutes. The number of cycles is 15 to 30, and the fumigation temperature is 80 to 100 ℃.

5. The method for directional caramelization of chili peppers according to claim 4, characterized in that, In step (3), during the smoking process, the smoke comes from the oxygen-controlled pyrolysis of hardwood materials; the smoke source is one or more of oak, birch, apple and cherry wood.

6. The method for directional caramelization of chili peppers according to claim 5, characterized in that, In step (3), the smoke source is composed of 30% to 60% oak, 10% to 30% birch, 10% to 30% apple wood, and 5% to 20% cherry wood; the oxygen-controlled pyrolysis temperature is 320 to 450 ℃, and the oxygen concentration is 2% to 8%.

7. The method for directional caramelization of chili peppers according to any one of claims 1-6, characterized in that, In step (4), the flavor precursor solution is composed of the following raw materials in percentage: 0.5-3% reducing sugar, 0.2-1.5% amino acids, 0.05-0.3% guar gum, and the balance being water; the reducing sugar is one or more of glucose, fructose, and maltose; the amino acid is one or more of glycine, alanine, and cysteine.

8. The method for directional caramelization of chili peppers according to claim 1 or 7, characterized in that, In step (4), the parameters of the electromagnetic instantaneous coking treatment are: surface temperature 320~450 ℃ and treatment time 5~30 s.

9. A chili pepper with a complex flavor of smoky aroma, caramel aroma and chili aroma prepared by the method according to any one of claims 1-8.

10. A compound seasoning containing the chili pepper of claim 9, characterized in that, The ingredients are: 40%–80% chili powder, 10%–30% salt, 2%–10% garlic powder, 2%–8% onion powder, 1%–5% black pepper, 1%–6% cumin, 0.5%–3% Sichuan peppercorns, and 0.5%–3% coriander seed powder.

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