Method for reducing the perception of pungency of chili oil by enzymatic release of endogenous reducing sugars in cooperation with a maillard reaction and chili oil product

Abstract

This invention relates to a method for reducing the perceived spiciness of chili oil through enzymatic hydrolysis and the release of endogenous reducing sugars in synergistic Maillard reaction. The method includes the following steps: 1) Crushing dried chili flakes using liquid nitrogen at low temperature, sieving, and freezing to obtain broken-cell-wall chili powder; 2) Performing targeted enzymatic hydrolysis of the broken-cell-wall chili powder using cellulase to obtain enzymatically hydrolyzed chili powder; 3) Frying the enzymatically hydrolyzed chili powder in vegetable oil to induce a Maillard reaction; 4) Allowing the fried chili powder to stand at room temperature, filtering, and collecting the supernatant to obtain the chili oil product. This method solves the problem in existing technologies where reducing spiciness requires reducing capsaicin content, thus affecting flavor characteristics.

Description

Technical Field

[0001] This invention belongs to the field of food processing technology, specifically relating to a method for reducing the perceived spiciness of chili oil by utilizing enzymatic decomposition to release endogenous reducing sugars in conjunction with the Maillard reaction, and a chili oil product prepared by this method. Background Technology

[0002] Chili oil, a traditional Chinese condiment, has a wide market application. Capsaicin is its core flavor and functional active ingredient, but high concentrations of capsaicin can easily cause burning and stinging sensations in the mouth, limiting its consumer base and application scenarios. To reduce the sensory irritation of chili oil, existing technologies mainly employ physical dilution, sensory masking, or chemical removal. For example, physical dilution reduces capsaicin concentration by adding other oils or ingredients, but this also dilutes the overall flavor and color of the chili oil, leading to a decline in product quality. Microencapsulation technology can mask the spiciness, but it relies on synthetic wall materials, making the process complex and costly, and difficult to adapt to large-scale industrial production. Adsorption removal directly removes capsaicin using adsorbents, a "subtractive" process that inevitably results in the loss of functional components. The common limitation of these methods is that they all achieve spiciness reduction by lowering the absolute content of capsaicin, failing to simultaneously meet the dual requirements of "low irritation" and "high activity."

[0003] For a long time, existing technologies have generally held that spiciness intensity is strictly positively correlated with capsaicin content, meaning that reducing spiciness must come at the cost of losing capsaicin-like substances. However, our team discovered in our research that endogenous glycosides present in the chili matrix can release reducing sugars under enzymatic hydrolysis, which then undergo Maillard reactions with amino acids. This reaction not only imparts characteristic flavors to the product, but its reaction products can also significantly modify the perceived spiciness of chili oil. This discovery indicates that by regulating the chemical reactions of matrix components, it is possible to reduce the perceived spiciness while retaining or even increasing capsaicin content.

[0004] While the Maillard reaction has been applied in areas such as oil flavor enhancement (e.g., rapeseed oil processing) and tobacco harm reduction, its technical purpose is mostly limited to flavor modification or reducing the chemical irritation of smoke, and its mechanism of action is quite different from the pain / heat sensation regulation of chili oil. Currently, in the field of chili oil processing, there are no reports of using enzymatic decomposition to release endogenous reducing sugars in conjunction with the Maillard reaction to regulate spiciness perception. Therefore, developing a simple, green, and safe chili oil processing method that can achieve "mild spiciness + high capsaicin retention" is a pressing technical challenge in this field. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a method for reducing the perceived spiciness of chili oil by utilizing enzymatic decomposition to release endogenous reducing sugars in conjunction with the Maillard reaction, as well as a chili oil product prepared by this method. This method solves the problem in existing technologies that reducing spiciness requires reducing capsaicin content, thus affecting flavor characteristics.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A method for reducing the perceived spiciness of chili oil by enzymatically releasing endogenous reducing sugars in conjunction with the Maillard reaction, comprising the following steps: 1) The dried chili flakes are subjected to liquid nitrogen cryogenic pulverization, sieved, and then frozen to obtain broken chili powder; 2) The cell wall-broken chili powder was subjected to targeted enzymatic hydrolysis using cellulase to obtain enzymatically hydrolyzed chili powder; 3) The enzymatically hydrolyzed chili powder was fried in vegetable oil to carry out the Maillard reaction; 4) After frying, let it stand at room temperature, filter it, and take the supernatant to obtain the chili oil product.

[0007] Specifically, in step 1), the dried chili raw material is stored in a refrigerator at -20±10℃ for later use. When using it, the dried chili raw material is first destemmed and seeded and cut into small pieces of (4-6) mm × (4-6) mm to obtain dried chili fragments.

[0008] Furthermore, in step 1), the dried chili flakes are pulverized at low temperature using a liquid nitrogen grinder (intermittent grinding for 1-2 minutes), passed through a 20-60 mesh sieve, and then frozen at -80±20℃ for 4-5 hours.

[0009] Specifically, in step 2), take the broken-cell wall chili powder, add purified water at a ratio of 1g:3-4ml, and add 1.5-2% of cellulase by weight of the broken-cell wall chili powder. Then, enzymatically hydrolyze the mixture at 45-55℃ for 3-4 hours.

[0010] Furthermore, in step 2), after enzymatic hydrolysis, the enzyme is inactivated in a boiling water bath at 90-100℃ for 8-15 minutes, and then dried in a vacuum drying oven at 50-55℃ until the moisture content is 10%-15%.

[0011] Specifically, in step 3), the vegetable oil is one or more of soybean oil, rapeseed oil, or corn oil.

[0012] Furthermore, in step 3), the mass ratio of enzymatically hydrolyzed chili powder to vegetable oil is 1:9-10; and the mixture is dynamically fried at 500-700 rpm for 8-10 minutes under heating conditions of 140-160℃.

[0013] Specifically, in step 4), after frying, let it stand at room temperature (20-30℃) for 2-4 hours for extraction, and then filter it through a 150-300 mesh sieve.

[0014] The present invention also provides a chili oil product prepared by the above method.

[0015] As a preferred technical solution, the present invention provides a method for reducing the perceived spiciness of chili oil by utilizing enzymatic decomposition to release endogenous reducing sugars in conjunction with the Maillard reaction, which specifically includes the following steps: 1) Low-temperature cell wall breaking pretreatment of raw materials: Store dried chili raw materials in a refrigerator at -20±10℃ for later use. When using, first remove the stems and seeds from the dried chili raw materials and cut them into small pieces of (4-6) mm × (4-6) mm to obtain dried chili fragments; then use a liquid nitrogen grinder to perform low-temperature pulverization of the chili fragments, pass them through a 20-60 mesh sieve, and freeze them at -80±20℃ for 4-5 h. The purpose is to accelerate the cell wall rupture of the raw materials, thereby releasing more endogenous substances and obtaining cell wall broken chili powder. 2) Targeted Enzymatic Hydrolysis: The low-temperature crushed chili powder is subjected to targeted enzymatic hydrolysis using cellulase to release more endogenous reducing sugars. Specifically: Take dried chili powder, add purified water at a material-to-liquid ratio of 1:3-1:4 g / ml, and simultaneously add cellulase at a ratio of 1.5%-2% of the weight of the crushed chili powder. Hydrolyze at 45-55℃ for 3-4 hours. After hydrolysis, inactivate the enzyme in a boiling water bath at 90-100℃ for 10 minutes, and then dry in a vacuum drying oven at 50-55℃ until the moisture content is approximately 10%-15%, obtaining hydrolyzed chili powder for later use. The purpose of drying is to reduce the moisture content of the raw material and inhibit microbial growth; at the same time, an appropriate amount of moisture ensures the smooth progress of the Maillard reaction. 3) Maillard reaction: Add enzymatically hydrolyzed chili powder to vegetable oil (one or more of soybean oil, rapeseed oil or corn oil) at a mass ratio of 1:9-1:10 (m / m), and then dynamically fry the enzymatically hydrolyzed chili powder at 140-160℃ (500-700rpm) for 8-10 minutes to activate and release more flavor substances under relatively mild conditions. 4) Post-processing: After frying, let stand at room temperature (20-30℃) for 2-4 hours for extraction. After filtering through a 200-mesh sieve, take the supernatant to obtain a chili oil product with a mild flavor (its volatile flavor substances include 2-furfural, 2,3-pentanedione, 3-(methylthio)propanal, 2-furan methanol and 2-phenylacetaldehyde, etc.) and reduced spiciness perception (spiciness perception is manifested as a point-like, delayed stimulation pattern, lasting for 1-3 minutes).

[0016] Compared with the prior art, the present invention has the following significant advantages and beneficial effects: (1) Significantly increased capsaicin content: Through low-temperature cell wall disruption pretreatment and directional cellulase hydrolysis, the cell wall is fully destroyed, and capsaicin-like substances in the chili matrix are efficiently released, increasing the capsaicin content in chili oil by 20.89% compared with traditional processes; at the same time, the endogenous reducing sugar in the matrix is ​​fully released, and the product obtained through Maillard reaction interacts with capsaicin in the matrix, thereby reducing the perception of spiciness stimulation while increasing the capsaicin content, breaking through the traditional technical understanding that "reducing spiciness will inevitably damage activity".

[0017] (2) Significantly reduced spiciness perception: According to the sensory evaluation team, the burning sensation score of the chili oil prepared by this invention was reduced by 25.5%-55.1% compared with the comparative sample, the stinging sensation score was reduced by 25%-58.3% compared with the comparative sample, and the mildness score was increased by 14.3%-220%, achieving the product characteristics of "mild spiciness" and expanding the applicable population and consumption scenarios.

[0018] (3) Significantly improved flavor quality: The Maillard reaction produces more characteristic flavor compounds such as pyrazines and furans, as well as more sweet and meaty aroma compounds, mainly 2,3-pentanedione, 2-furanol, 3-(methylthio)propanal, 2-phenylacetaldehyde, and 2-furfural, which mainly contribute to sweet, roasted, meaty, and fruity aromas. This significantly improves the overall flavor harmony of chili oil and solves the problem of "reducing spiciness equals reducing quality" caused by physical dilution.

[0019] (4) Simple process and controllable cost: This solution only requires conventional steps such as low temperature cell disruption, enzymatic hydrolysis, frying and filtration. It does not require synthetic wall materials for microencapsulation or a large amount of adsorbent consumption as in adsorption methods. The process is simple, low-cost and easy to promote industrially.

[0020] (5) Green and safe, no additives: This solution achieves flavor adjustment through the natural reaction of endogenous components without introducing any exogenous chemical additives, which is in line with the development trend of clean label and green processing. Attached Figure Description

[0021] Figure 1 Radar charts were used to quantitatively describe and analyze the aroma perception of chili oil prepared by different methods. Figure 2 Radar charts were used to quantitatively describe and analyze the spiciness perception of chili oils prepared by different methods. Figure 3 Two-dimensional GC-IMS spectra of volatile compounds in chili oils prepared by different methods (from left to right: Comparative Example 1, Comparative Example 2, Comparative Example 3 and Example 1); Figure 4 Gallery fingerprints of volatile compounds in chili oil prepared by different methods. Detailed Implementation

[0022] The technical solution of the present invention will be further described in detail below with reference to the embodiments, but the scope of protection of the present invention is not limited thereto.

[0023] To make the objectives, technical solutions, and advantages of the present invention more readily understood, the present invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention.

[0024] In the following examples, all raw materials used were common commercially available products that could be purchased directly, or could be prepared using conventional methods in the art. For example, the cellulase used (enzyme activity 50 U / mg) was purchased from Novozymes.

[0025] For any operations or parameters not detailed in subsequent evaluations and measurements, conventional techniques in this field can be used. Example 1

[0026] A method for reducing the perceived spiciness of chili oil by utilizing enzymatic decomposition to release endogenous reducing sugars in conjunction with the Maillard reaction, specifically includes the following steps: (1) Raw material preparation: Select dried chili raw materials (variety: Sichuan Erjingtiao), with a moisture content of 10-15%, remove the stems and seeds, and cut into (4-6) mm × (4-6) mm small pieces to obtain dried chili fragments; (2) Low-temperature cell wall breaking pretreatment: The chili raw material was subjected to low-temperature pulverization using a liquid nitrogen grinder (the sample was soaked in liquid nitrogen to make it brittle before grinding, with intermittent grinding for 1 min); after pulverization, it was passed through a 40-mesh sieve to obtain chili powder. The chili powder was frozen at -80℃ for 4 h to fully break the cell walls and release endogenous capsaicin, reducing sugars and amino acids to obtain cell wall broken chili powder; (3) Enzymatic hydrolysis: The low-temperature crushed chili powder was added to purified water at a material-to-liquid ratio of 1:4 (g / ml), and 1.5% (by weight of the crushed chili powder) of cellulase (enzyme activity 50 U / mg, purchased from Novozymes) was added simultaneously. Enzymatic hydrolysis was carried out at 45℃ for 3 h. After enzymatic hydrolysis, the enzyme was inactivated in a boiling water bath at 100℃ for 10 min. The enzyme-inactivated material was dried in a vacuum drying oven at 50℃ until the moisture content was 15%, to obtain enzymatically hydrolyzed chili powder. (4) Maillard reaction / frying: Heat 200 g of edible oil (soybean oil) to 160°C, add 20 g of enzymatically hydrolyzed chili powder to the hot oil, and fry dynamically at 160°C and 650 rpm for 10 min. (5) Post-processing: After frying, stop heating and let stand at room temperature for 2 hours for extraction. After filtering through a 200-mesh sieve, take the supernatant to obtain the chili oil product of Example 1.

[0027] Comparative Example 1 A method for preparing a chili oil product (traditional chili oil process, without enzymatic hydrolysis) is as follows:

[0028] (1) Raw material preparation: Select dried chili raw materials (variety: Sichuan Erjingtiao), with a moisture content of 10-15%, remove the stems and seeds, and cut into (4-6) mm × (4-6) mm small pieces to obtain dried chili fragments; (2) Low-temperature cell wall disruption pretreatment: The chili raw material was subjected to low-temperature pulverization using a liquid nitrogen grinder (the sample was soaked in liquid nitrogen to make it brittle before grinding, with intermittent grinding for 1 min); after pulverization, it was passed through a 40-mesh sieve to obtain chili powder. The chili powder was frozen at -80℃ for 4 h to fully rupture the cell walls and obtain cell wall disrupted chili powder; (3) Maillard reaction / frying: Heat 200 g of edible oil (soybean oil) to 160°C, add 20 g of the broken chili powder obtained in step (2) to the hot oil, and fry dynamically at 160°C and 650 rpm for 10 min. (4) Post-processing: After frying, stop heating and let stand at room temperature for 2 hours for extraction. After filtering through a 200-mesh sieve, take the supernatant to obtain the chili oil product of Comparative Example 1.

[0029] Comparative Example 2 A method for preparing chili oil (using pectinase treatment) is as follows:

[0030] (1) Select dried chili raw materials (variety: Sichuan Erjingtiao), with a moisture content of 10-15%, remove the stems and seeds, and cut them into (4-6) mm × (4-6) mm small pieces to obtain dried chili fragments; (2) Low-temperature cell wall breaking pretreatment: The chili raw material was subjected to low-temperature pulverization using a liquid nitrogen grinder (the sample was soaked in liquid nitrogen to make it brittle before grinding, with intermittent grinding for 1 min); after pulverization, it was passed through a 40-mesh sieve to obtain chili powder. The chili powder was frozen at -80℃ for 4 h to fully break the cell walls and release endogenous capsaicin, reducing sugars and amino acids to obtain cell wall broken chili powder; (3) Enzymatic hydrolysis: The low-temperature crushed chili powder was added to purified water at a material-to-liquid ratio of 1:4 (g / ml), and 1.5% of the weight of the crushed chili powder was added with pectinase (enzyme activity 30 U / mg, purchased from Shandong Longket Enzyme Preparation Co., Ltd.). Enzymatic hydrolysis was carried out at 45℃ for 3 h. After enzymatic hydrolysis, the enzyme was inactivated in a boiling water bath at 100℃ for 10 min. The enzyme-inactivated material was dried in a vacuum drying oven at 50℃ until the moisture content was 15% to obtain enzymatically hydrolyzed chili powder. (4) Maillard reaction / frying: Heat 200 g of edible oil (soybean oil) to 160°C, add 20 g of enzymatically hydrolyzed chili powder to the hot oil, and fry dynamically at 160°C and 650 rpm for 10 min. (5) Post-processing: After frying, stop heating and let stand at room temperature for 2 hours for extraction. After filtering through a 200-mesh sieve, take the supernatant to obtain the chili oil product of Comparative Example 2.

[0031] Comparative Example 3

[0032] A method for preparing a chili oil product (using flavor protease treatment) is as follows: (1) Select dried chili raw materials (variety: Sichuan Erjingtiao), with a moisture content of 10-15%, remove the stems and seeds, and cut them into (4-6) mm × (4-6) mm small pieces to obtain dried chili fragments; (2) Low-temperature cell wall breaking pretreatment: The chili raw material was subjected to low-temperature pulverization using a liquid nitrogen grinder (the sample was soaked in liquid nitrogen to make it brittle before grinding, with intermittent grinding for 1 min); after pulverization, it was passed through a 40-mesh sieve to obtain chili powder. The chili powder was frozen at -80℃ for 4 h to fully break the cell walls and release endogenous capsaicin, reducing sugars and amino acids to obtain cell wall broken chili powder; (3) Enzymatic hydrolysis: The low-temperature crushed chili powder was added to purified water at a material-to-liquid ratio of 1:4 (g / ml), and 1.5% of the chili powder mass of flavor protease (enzyme activity 15 U / mg, purchased from Nanning Pangbo Biotechnology Co., Ltd.) was added. Enzymatic hydrolysis was carried out at 45℃ for 3 h. After enzymatic hydrolysis, the enzyme was inactivated in a boiling water bath at 100℃ for 10 min. The enzyme-inactivated material was dried in a vacuum drying oven at 50℃ until the moisture content was 15% to obtain enzymatically hydrolyzed chili powder. (4) Maillard reaction / frying: Heat 200 g of edible oil (soybean oil) to 160°C, add 20 g of enzymatically hydrolyzed chili powder to the hot oil, and fry for 10 min under dynamic conditions of 160°C and 650 rpm. (5) Post-processing: After frying, stop heating and let stand at room temperature for 2 hours for extraction. After filtering through a 200-mesh sieve, take the supernatant to obtain the chili oil product of Comparative Example 3.

[0033] I. Evaluation and Measurement Methods.

[0034] Sensory Evaluation: Following the sensory evaluation requirements stipulated in the People's Republic of China National Standard (GB / T 16291.1-2012) and the Institute of Food Science and Technology (IFST) Guidelines for Ethical and Professional Practice in Sensory Analysis of Food, quantitative descriptive analysis (QDA) was used to analyze the main aroma and spiciness characteristics of different chili oil samples. All sensory evaluators (18 women and 12 men, aged 22-40 years) had previously received systematic training in descriptive sensory analysis. The training consisted of three parts: first, the sensory team described the main aroma and spiciness characteristics of the chili oil without providing descriptive terms; then, the evaluators discussed all descriptive terms; finally, the evaluators were asked to evaluate again and score the selected descriptive terms. 2.00 g of each chili oil sample was used for sensory evaluation. The intensity of the description was scored on a 10-point scale, with 0 representing "none" and 10 representing "very strong". The experiment was repeated three times, and the final score was the average of the evaluation results from each sensory evaluator.

[0035] Qualitative multidimensional analysis (QMA) was used to assess the perceived spiciness of chili oil. Spiciness is characterized by the intensity and duration of the burning sensation in the oral cavity. QMA covers three key aspects: site of stimulation (first and strongest point), dynamic characteristics (attributes, delay time, and duration), and spatial transmission mode. Sites of stimulation include the palate, tongue, lips, and throat; the dynamic characteristics of spiciness are categorized as delayed or explosive burning sensation; and the spatial transmission mode is classified as point-like or area-like stimulation based on the burning sensation.

[0036] Determination of capsaicin and spiciness: The capsaicin content was determined using a 1260 Infinity II high-performance liquid chromatograph according to the national standard GB / T21266-2007 "Determination of Capsaicin and Expression of Spiciness in Chili Peppers and Chili Products". 2.50 g of sample (accurate to 0.001 g) was weighed and added to a 1:1 (v / v) mixture of methanol and tetrahydrofuran. The mixture was ultrasonically extracted for 30 min at 60℃. The filtrate was collected, and the residue, along with the filter paper, was added back to the mixed solvent and ultrasonically extracted for 10 min, repeated twice. The three filtrates were combined and concentrated to 10 ml using a rotary evaporator at 70℃. The volume was then adjusted to 25 ml with the mixed solvent and filtered through a 0.22 μm filter membrane before analysis.

[0037] Calibration curves for capsaicin and dihydrocapsaicin were constructed using the external standard method to further determine their contents. The total capsaicin content was then calculated by dividing the contents by 0.9. The calculation formula is shown in equation (1): .

[0038] M: Total amount of capsaicin compounds (g / kg); Ma: Capsaicin content (g / kg); Mb: Dihydrocapsaicin content (g / kg); 0.9: Coefficient of conversion of capsaicin and dihydrocapsaicin into capsaicin compounds.

[0039] The total content of capsaicin compounds is converted to SHU according to formula (2): .

[0040] M: Total amount of capsaicin compounds (g / kg); 0.9: Conversion factor for total amount of capsaicin compounds; 16.1 × 10⁻⁶ 3 : The coefficient for converting capsaicin or dihydrocapsaicin to the Scoville index; 0.1: The conversion factor for other capsaicin compounds; 9.3 × 10 3 : The coefficient for the conversion of other capsaicin compounds to SHU.

[0041] Detection of volatile flavor compounds: Accurately weigh 1.00 g of chili oil sample into a 20 mL headspace vial sealed with a PTFE septum. Incubate the headspace vial at 60℃ and 250 r / min for 10 min; inject 500 µL of the headspace sample without splitting. The syringe temperature was 80℃, the pre-injection cleaning time was 30 s, and the post-injection cleaning time was 6 min. GC conditions: MXT-5 column (15 m × 0.53 mm × 0.53 µm); column temperature 40℃; carrier gas was high-purity nitrogen (≥99.999%). The carrier gas flow program was as follows: initial 2.0 mL / min, hold for 2 min, linearly increase to 5.0 mL / min from 2 to 10 min, linearly increase to 50.0 mL / min from 10 to 20 min, linearly increase to 100.0 mL / min from 20 to 30 min, then stop the flow. The total run time was 30 min. IMS conditions: drift tube length 98 mm; drift tube temperature 60 °C; drift gas nitrogen (purity ≥99.999%); drift gas flow rate 150 mL / min; tube linear voltage 500 V / cm; radiation source β-rays (tritium, 3H); positive ion mode; average number of spectral scans 12.

[0042] GC-IMS data were extracted and analyzed using the instrument's built-in LAV (Laboratory Analytical Viewer) software and two plugins (Reporter plugin and Gallery Plot plugin) to construct differential and fingerprint profiles of volatile organic compounds. Qualitative analysis of flavor compounds was performed using the software's built-in NIST 2014 gas phase retention index database and IMS migration time database. The retention and migration times (time required for ions to reach the collector via the drift tube, in milliseconds) of characteristic volatile compounds were compared. The retention index (RI) of each volatile compound was calculated using external standard n-ketones C4-C9 as a reference, and the volatile compounds were then identified and analyzed by matching with the GC-IMS library.

[0043] II. Test Results.

[0044] The chili oil products prepared in the above embodiments and comparative examples were systematically compared. The evaluation was carried out from three dimensions: sensory characteristics (spiciness perception and aroma perception), capsaicin content, and volatile flavor composition. The results are as follows.

[0045] 1. Sensory evaluation results.

[0046] 1.1 Quantitative descriptive analysis of odor perception.

[0047] Sensory evaluation of the aroma characteristics of chili oil samples treated with different enzymatic hydrolysis methods was conducted using quantitative descriptive analysis. Results are as follows: Figure 1 As shown, the evaluation team used a total of 6 sensory descriptive terms (raw, green, spicy, oily, roasted, caramelized, and overall flavor) for identification and quantitative description. Figure 1The results showed that the chili oil prepared using the embodiments of the present invention was significantly superior to the comparative examples in terms of overall flavor, roasted aroma, and sweet caramel aroma. Specifically, the overall flavor score of the embodiment was 8.0, which was 45.5% higher than that of the traditional process (Comparative Example 1, 5.5); the roasted aroma score was 7.0, which was 66.7% higher than that of Comparative Example 1 (4.2); the sweet caramel aroma score was 8.2, which was 115.8% higher than that of Comparative Example 1 (3.8); and the raw green flavor score of the embodiment was 3.0, which was the lowest level among all samples, indicating that no unpleasant flavor was produced. Comparative Example 1 (untreated oil) exhibited a strong oily aroma and spiciness, but its overall flavor quality was rather stimulating and monotonous. Comparative Example 2, treated with pectinase, had a milder spiciness (5.7), but a prominent raw, grassy taste (7.0), affecting its overall harmony. Comparative Example 3, treated with flavor protease, had the lowest spiciness (5.0) and the highest oily aroma (7.5), with an overall flavor superior to the other two (7.2), but its roasted aroma (4.6) and caramel sweet aroma (6.5) were still far lower than the examples. In contrast, the example sample treated with cellulase showed the best flavor performance, with a harmonious and balanced spiciness, rich aroma layers, and a complex aroma that blended roasted, caramel sweet, and oily notes, while avoiding unpleasant off-flavors such as raw, grassy taste. In summary, the chili oil product prepared using the method of this invention has a richer and more intense aroma, with a harmonious and unified spiciness.

[0048] 1.2 Quantitative descriptive analysis and qualitative multidimensional analysis of spiciness perception.

[0049] The perception of spiciness is a complex sensory response involving intensity, temporal variation, spatial distribution, and stimulus location. To further evaluate the impact of the method of this invention on the perception of spiciness from chili oil, quantitative descriptive analysis and quantitative multi-attribute analysis were performed.

[0050] Quantitative descriptive analysis was used to evaluate the perceived spiciness of different chili oil samples, including spiciness, burning sensation, stinging sensation, astringency, and mellowness. Results are as follows: Figure 2As shown, Comparative Example 1 exhibited the strongest spiciness, burning sensation, and stinging sensation, with the lowest mildness, indicating that traditional chili oil is highly irritating and lacks comfort. Comparative Examples 2 and 3 showed a slight decrease in spiciness, but a significant reduction in burning and stinging sensations, and a substantial increase in mildness, indicating that low-temperature cell wall disruption pretreatment synergistically with enzymatic hydrolysis and the Maillard reaction itself contributes to improving the spiciness quality. It is noteworthy that the sample prepared using the method of this invention (low-temperature cell wall disruption pretreatment synergistically with directional cellulase hydrolysis and Maillard reaction), although slightly more spicier than Comparative Example 3, had the lowest burning and stinging sensations among all samples, decreasing by 55.1% and 58.3% respectively compared to Comparative Example 1; simultaneously, the mildness reached the highest value of 8.0, an increase of 220% compared to Comparative Example 1, and also significantly improved compared to Comparative Examples 2 and 3. The above results demonstrate that the method of the present invention can significantly suppress the burning and stinging sensations in spiciness while retaining a moderate level of spiciness, transforming the perception of spiciness into a milder and more comfortable sensation, thus achieving the technical effect of "low stimulation and high gentleness".

[0051] Qualitative multidimensional analysis was used to evaluate the spatiotemporal perception characteristics of spiciness in different chili oil samples, covering dimensions such as the initial sensory location, the strongest sensory location, spatial transmission mode, dynamic attributes, delay time, and duration. The results are shown in Table 1. As shown in Table 1, Comparative Example 1 (traditional process) exhibited an explosive, planar stimulation pattern: the spiciness initially appeared on the tongue, rapidly spreading to the throat to become the strongest sensory area, with a very short delay time (0-3 s) and a long duration (3-5 min), indicating that its spiciness perception was strong, sharp, and difficult to subside. After being processed using the methods of Comparative Examples 2 and 3, the transmission mode changed to point-like, the dynamic attributes changed to delayed, the delay time increased to 2-4 s, and the duration shortened to 2-4 min or 1-3 min, indicating that low-temperature cell wall disruption pretreatment synergistically with enzymatic hydrolysis and the Maillard reaction itself helped to alleviate the explosiveness and diffusion of spiciness. It is worth noting that Embodiment 1 of the present invention further optimizes the spiciness perception characteristics: its initial and strongest sensation locations are limited to the tongue and do not spread to the throat or palate; the transmission mode is point-like, the dynamic attribute is delayed, with the longest delay time (3-5 s) and the shortest duration (1-3 min). Compared with Comparative Example 1, the delay time of Embodiment 1 is extended by 2-5 seconds, and the duration is shortened by 2-4 min; compared with Comparative Examples 2 and 3, the stimulation location of Embodiment 1 is more concentrated (only the tongue), and the delay time is longer or the duration is shorter.

[0052] Table 1. Qualitative multidimensional analysis results of spiciness perception of chili oils prepared by different methods.

[0053] Note: "Delay time": the time from when the sample comes into contact with the tongue to when the spiciness is first perceived; "Duration": the duration of the spiciness in the mouth.

[0054] The above results indicate that the method of the present invention (low-temperature cell wall disruption pretreatment combined with directional cellulase hydrolysis and Maillard reaction) can transform the perception of spiciness in chili oil from "explosive, diffuse, and long-lasting" to "delayed, localized, and short-lasting," and effectively limit the stimulating area to the tongue, preventing it from spreading to sensitive areas such as the throat, thereby significantly reducing the irritation of spiciness and effectively improving the mildness and comfort of spiciness.

[0055] 2. Comparative analysis of capsaicin content.

[0056] Table 2 shows the comparison of capsaicin content and spiciness of chili oils prepared by different treatment methods. As shown in Table 2, the total capsaicin content of the three enzymatic treatment groups—cellulase (Example 1), pectinase (Comparative Example 2), and flavor protease (Comparative Example 3)—was significantly higher than that of the traditional frying method (Comparative Example 1), at 223.54±1.00 μg / g, 218.63±5.59 μg / g, and 221.81±1.25 μg / g, respectively, representing an increase of 18.24%-20.89% compared to Comparative Example 1 (184.91±3.27 μg / g). Among them, the cellulase treatment showed the best effect, with an SHU index of 3446.92±15.42, an increase of 20.89% compared to the traditional frying method (2851.26±50.44). The differences among the three enzymatic methods were small (<2.5%), indicating that although the different enzymes have different target sites, they can all release capsaicin from vacuoles by disrupting the cell wall structure, resulting in similar enhancement effects. However, cellulase was superior to the other enzymes, possibly because it directly acts on the main skeletal components of the cell wall (cellulose accounts for 36%-70% of the cell wall), and can more effectively disrupt the cell wall and release capsaicin compared to pectin (intercellular layer, accounting for 19%-21%) and flavor proteases (acting on proteins). In addition, the standard deviation of the experimental data in Example 1 was generally lower than that of the comparative group, indicating that the process stability and reproducibility of this method are better.

[0057] Table 2 Comparison of spiciness of chili oils prepared by different methods

[0058] The above results demonstrate that enzymatic treatment achieves efficient release of capsaicin by degrading cell wall components, which has a significant advantage in extraction efficiency compared to the traditional frying method, and cellulase is the better enzyme choice.

[0059] 3. Analysis of volatile flavor compounds based on GC-IMS.

[0060] 3.1 Comparison of two-dimensional spectra.

[0061] The Reporter plugin was used to generate two-dimensional GC-IMS spectra of volatile compounds in chili oils prepared through different processes. The results are as follows: Figure 3 As shown. The red vertical line at the x-axis (1.0) represents the reaction ion peak (normalized). Each point to the right of the reaction ion peak represents a volatile compound, and the color indicates the signal intensity of a single compound. Figure 3 As can be seen from the color perspective, there are significant differences between the different treated samples, which can be clearly distinguished intuitively. Among them, the number of volatile compounds in the chili oil sample of Example 1 is significantly greater than that of Comparative Example 2 and Comparative Example 3, indicating that the treatment by the method of the present invention can significantly increase the types and contents of volatile compounds in chili oil and enhance the overall aroma of chili oil.

[0062] 3.2 Qualitative analysis and fingerprint analysis of volatile flavor compounds.

[0063] Volatile compounds in chili oil samples with different treatments were analyzed using the GC-IMS built-in database. The results are shown in Table 3. A total of 33 compounds were identified, including 10 aldehydes, 5 alcohols, 7 ketones, 3 esters, 2 terpenes, 3 furans, 1 sulfur-containing compound, 1 nitrogen-containing compound, and 1 alkane.

[0064] Table 3. HS-GC-IMS results of volatile compounds in chili oil prepared by different methods.

[0065]

[0066]

[0067] Note: 1. Odor description: based on the GC-IMS built-in database and literature; D / M indicates the dimer / monomer form of the compound.

[0068] To more intuitively and quantitatively compare the differences in volatile components in chili oil samples under different treatment methods, the GalleryPlot plugin was used to generate fingerprint spectra of volatile compounds. The results are shown in [Figure number missing]. Figure 4 The brighter the spot, the higher the concentration of the compound. Unidentified substances are numbered with Arabic numerals. For example... Figure 4As shown, region A represents the flavor compounds in the chili oil sample prepared in Comparative Example 1, mainly including volatile compounds such as (E)-2-hexenal, 1-penten-3-ol, 1-pentanol, (E)-2-pentenal, 3-hexanone, ethylbenzene, methyl furoate, 1-heptanal, hexanal, pentanal, 2-pentanone, and 1-hydroxy-2-propanone, contributing to the green aroma, lipid aroma, and spicy and pungent flavor; region B represents the flavor compounds in the chili oil sample prepared in Comparative Example 2, mainly including 2-propanone, 1-Penten-3-one, 2-pentylfuran, (E)-2-heptenal, and 1-octen-3-one contribute to the aroma, fruitiness, and pungent flavor. Region C contains newly generated volatile compounds in the chili oil samples prepared in the examples, including 2,3-pentanedione, 2-furanethanol, 3-(methylthio)propanal, 2-phenylacetaldehyde, and 2-furfural, which mainly contribute to the aroma, roasting, meatiness, and fruitiness. These compounds are not present in the chili oil prepared by the comparative process.

[0069] Overall, the chili oil prepared by the method of the present invention can produce sweet aroma, roasted aroma, meaty aroma and fruity aroma, thus making the aroma of chili oil richer and fuller, and with a stronger sense of layering.

[0070] 4. Summary of technical effects.

[0071] Although the capsaicin content in the chili oil prepared by this invention is significantly higher than that of traditional processes, its perceived irritation is significantly reduced. This "high content, low irritation" technical effect can be explained from two levels: sensory physiology and processing technology. Physiologically, cellulase pretreatment increases the level of endogenous reducing sugars, promotes the formation of sweet-smelling compounds via the Maillard reaction, and effectively alleviates capsaicin-induced burning and stinging sensations by activating the central sweet-spicy sensory interaction inhibition pathway through matrix effects. Physically, the spatiotemporal transmission pattern of spiciness stimulation changes from the "burst-type, surface-like, short-delay, long-lasting" of traditional processes to "delayed-type, point-like, long-delay, short-lasting," with the stimulation area shrinking to the tongue and the duration shortened. The synergistic effect of these two mechanisms enables this invention to significantly reduce the perceived spiciness while retaining or even increasing the capsaicin content, breaking through the traditional technical understanding that "reducing spiciness inevitably damages activity."

[0072] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for reducing the perceived spiciness of chili oil through enzymatic decomposition and release of endogenous reducing sugars in conjunction with the Maillard reaction, characterized in that, Includes the following steps: 1) Grind the dried chili flakes, sieve them, and freeze them to obtain broken chili powder; 2) The cell wall-broken chili powder was subjected to targeted enzymatic hydrolysis using cellulase to obtain enzymatically hydrolyzed chili powder; 3) The enzymatically hydrolyzed chili powder was fried in vegetable oil to carry out the Maillard reaction; 4) After frying, let it stand at room temperature, filter it, and take the supernatant to obtain the chili oil product.

2. The method of claim 1, wherein, In step 1), the dried chili raw material is stored in a refrigerator at -20±10℃ for later use. When using it, first remove the stems and seeds from the dried chili raw material and cut it into small pieces of (4-6) mm × (4-6) mm to obtain dried chili fragments.

3. The method of claim 1, wherein, In step 1), the dried chili flakes are pulverized at low temperature using a liquid nitrogen grinder, passed through a 20-60 mesh sieve, and then frozen at -80±20℃ for 4-5 hours.

4. The method of claim 1, wherein, In step 2), take the broken-cell wall chili powder, add purified water at a ratio of 1g:3-4ml, and add 1.5-2% of cellulase by weight of the broken-cell wall chili powder. Then, enzymatically hydrolyze the mixture at 45-55℃ for 3-4 hours.

5. The method of claim 1, wherein, In step 2), after enzymatic hydrolysis, the enzyme is inactivated in a boiling water bath at 90-100℃ for 8-15 minutes, and then dried in a vacuum drying oven at 50-55℃ until the moisture content is 10%-15%.

6. The method of claim 1, wherein, In step 3), the vegetable oil is one or more of soybean oil, rapeseed oil, or corn oil.

7. The method as described in claim 1, characterized in that, In step 3), the mass ratio of enzymatically hydrolyzed chili powder to vegetable oil is 1:9-10; and the mixture is dynamically fried at 500-700 rpm for 8-10 minutes under heating conditions of 140-160℃.

8. The method of claim 1, wherein, In step 4), after frying, let it stand at room temperature (20-30℃) for 2-4 hours for extraction, and then filter it through a 150-300 mesh sieve.

9. A chili oil product prepared by any one of the methods described in claims 1 to 8.

Images