Method for rapidly simulating changes in oak flavour during barrel aging of alcoholic beverages

Abstract

This invention provides a method for rapidly simulating the changes in oak flavor during barrel aging of wines, belonging to the field of wine testing technology. This method employs enhanced ultrasonic extraction combined with solid-phase microextraction-gas chromatography-mass spectrometry to detect the content of oak flavor compounds in barrel-aged wines at different aging stages, enabling rapid prediction of the concentration range of oak flavor compounds in actual wine products at different aging stages. By simulating the changes in oak flavor during barrel aging of alcoholic beverages, this method can quickly predict the concentration range of oak flavor compounds in actual wine products at different aging stages, achieving rapid, accurate, efficient, and low-cost evaluation. Furthermore, it can be applied to the design and optimization of the flavor of barrel-aged products.

Description

Technical Field

[0001] This invention belongs to the field of wine testing technology, and in particular relates to a method for rapidly simulating changes in oak flavor during the barrel aging process of wine. Background Technology

[0002] Aging is an ancient traditional process still used today to improve the sensory quality of wines, spirits, and some specialty beers. Currently, with the gradual development of my country's economy and the continuous improvement of people's living standards, the consumer base for ultra-premium beers is also gradually expanding. Different educational levels, purchasing power, and living environments lead to varying consumer demands for beer, while the pace of innovation in high-quality products is not as fast as expected.

[0003] The main components of oak are cellulose, hemicellulose, lignin, and tannins, which significantly influence oak flavor and mouthfeel. The aging process dramatically alters the flavor profile of the spirit, noticeably increasing coconut, creamy, woody, and vanilla notes. Oak flavors, represented by oak lactones, furans, and phenolic compounds, contribute over 60% of the final flavor profile. Therefore, changes in these substances during aging directly affect the final quality of barrel-aged products, and these changes must be monitored to ensure the quality of the finished product. Furthermore, predicting the patterns of oak flavor changes during aging can provide valuable information for flavor design and optimization of barrel-aged products.

[0004] Traditional oak fortification testing typically employs a milder, long-term immersion method, soaking the oak in a 60% ethanol solution (or a matrix simulating other aged wines) for 3-6 months to simulate 3-4 year aged products. However, this method is too time-consuming, making it unsuitable for rapid product design and other needs. Magnetic stirring can significantly shorten this cycle to 12 hours, but this still doesn't fully meet the requirements for rapid prediction. Summary of the Invention

[0005] This invention provides a method for rapidly simulating changes in oak flavor during barrel aging of alcoholic beverages. By simulating the changes in oak flavor during barrel aging of alcoholic beverages, this method can quickly predict the concentration range of oak flavor substances in actual alcoholic products at different aging stages, achieving rapid, accurate, efficient, and low-cost evaluation. It can also be applied to the design and optimization of the flavor of barrel-aged products.

[0006] To achieve the above objectives, this invention provides a method for rapidly simulating changes in oak flavor during barrel aging of wines. It employs enhanced ultrasonic extraction combined with solid-phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS) to detect the content of oak flavor compounds in barrel-aged wines at different aging stages, thereby rapidly predicting the concentration range of oak flavor compounds in actual wine products at different aging stages. The key flavor compounds extracted from oak barrels are the same for different types of wines; the differences lie only in the content of the extracted substances based on different matrices and barrel aging times.

[0007] Preferably, the oak flavoring substances are eugenol, eugenol, vanillin, 4-ethylphenol, cis-oakolactone, and trans-oakolactone.

[0008] As a preferred option, a simulation curve equation was established for the relationship between different aging stages and the content of oak flavor compounds in barrel-aged wines, specifically:

[0009] Syringaldehyde: y = 966.82ln(x) - 306.27;

[0010] Eugenol: y = 31.975ln(x) - 11.154;

[0011] Vanillin: y = 203.91ln(x) - 197.59;

[0012] 4-Ethylphenol: y = 0.279ln(x) - 0.1092;

[0013] cis-oak lactone: y = 173.95ln(x) - 0.8348;

[0014] Trans-oakolide: y = 117.51ln(x) - 17.098.

[0015] y represents the content of oak flavor compounds, in μg / L; x represents the simulated number of days the wine has been aged in barrels.

[0016] As preferred methods, the accuracy rate for predicting flavor compounds after 1 month of barrel aging is 94.78%–106.92%; after 6 months of barrel aging, the accuracy rate is 92.40%–103.10%; after 12 months of barrel aging, the accuracy rate is 95.59%–102.21%; and after 36 months of barrel aging, the accuracy rate is 91.16%–104.06%.

[0017] As a preferred method, enhanced ultrasonic extraction specifically involves:

[0018] Weigh 0.04g of heavily carbonized oak chips and place them in a test bottle. Add 2mL of ethanol / water, where the volume ratio of ethanol to water is 60:40 and the pH is 5.5. Use 180W ultrasonic power, control the temperature to be less than 20℃, and set the ultrasonic time to 20s, 40s, 80s, 160s, and 320s respectively.

[0019] After sonication, the solution was filtered into a 20 mL headspace vial and diluted to an ethanol concentration of ≤20% for subsequent solid-phase microextraction-gas chromatography-mass spectrometry analysis.

[0020] As a preferred method, the solid-phase microextraction conditions are as follows: fiber extraction head: 65μm DVB / CAR / PDMS extraction head; extraction temperature: 40℃; pre-heating time: 2 min; extraction time: 15 min; elution time: 3 min.

[0021] As a preferred option, the gas chromatography-mass spectrometry conditions are:

[0022] A weakly polar capillary column (60 m × 0.32 mm × 0.25 μm) was used, with nitrogen as the carrier gas and a flow rate of 1.5 mL / min.

[0023] The column heating program is as follows: hold at 35℃ for 2 min, then increase to 60℃ at 7.5℃ / min and hold for 0.5 min, then increase to 240℃ at 15℃ / min and hold for 15 min;

[0024] The injection port temperature is 250℃, the electron bombardment energy is 70eV, and the ion source temperature is 230℃.

[0025] Preferably, the standard mass spectrometry library for the oak flavor compounds is the NIST standard mass spectrometry library.

[0026] Compared with the prior art, the advantages and positive effects of the present invention are as follows:

[0027] This invention utilizes enhanced ultrasonic extraction combined with solid-phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS) to rapidly simulate the changes in oak flavor during barrel aging of alcoholic beverages. It can quickly predict the concentration range of oak flavor substances in actual alcoholic beverages at different aging stages, and is applicable to the prediction of alcoholic beverages with different ethanol contents (beer, wine, brandy, and whiskey, etc.). It achieves rapid, accurate, efficient, and low-cost evaluation, and can be applied to the design and optimization of the flavor of barrel-aged products. Attached Figure Description

[0028] Figure 1 GC-MS selected ion map of flavor substances in ultrasonically treated oak chips provided in an embodiment of the present invention. Detailed Implementation

[0029] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] Example 1

[0031] Oak sample: American oak chips used in the bourbon whiskey cask aging process were carbonized at 225°C for 15 minutes to obtain heavily carbonized oak chips. This oak can be used in the cask aging process of Scotch whisky after completing the bourbon whiskey cask aging process.

[0032] Sample preparation: 0.04g of heavily carbonized oak chips were added to different test bottles, along with 2mL of ethanol / water (60% v / v, pH = 5.5). Understandably, 60% ethanol was used for extraction to obtain a larger and more concentrated amount of substances, which is more consistent with the actual conditions during whisky barrel aging.

[0033] Ultrasonic treatment: 180W ultrasonic power was used, and the temperature was controlled to be less than 20℃. The ultrasonic time was set to 20s, 40s, 80s, 160s and 320s respectively. After ultrasonication, the sample was filtered into a 20mL headspace vial and diluted to an ethanol concentration of less than 20% for solid phase microextraction-gas chromatography-mass spectrometry analysis.

[0034] Sample analysis:

[0035] Solid-phase microextraction conditions: fiber extraction head: 65μm DVB / CAR / PDMS; extraction temperature: 40℃; pre-heating time: 2 min; extraction time: 15 min; elution time: 3 min.

[0036] Gas chromatography-mass spectrometry conditions:

[0037] A weakly polar capillary column (60 m × 0.32 mm × 0.25 μm) was used, with nitrogen as the carrier gas and a flow rate of 1.5 mL / min.

[0038] The column heating program is as follows: hold at 35℃ for 2 min, then increase to 60℃ at 7.5℃ / min and hold for 0.5 min, then increase to 240℃ at 15℃ / min and hold for 15 min;

[0039] The injection port temperature is 250℃, the electron bombardment energy is 70eV, and the ion source temperature is 230℃.

[0040] Qualitative analysis of samples: The National Institute of Standards and Technology (NIST) standard mass spectrometry library was used.

[0041] Quantitative analysis of samples: Quantification was performed using a calibration curve based on a standard reference material (Sigma-Aldrich).

[0042] like Figure 1 As shown, the main flavor compounds in the oak chip extract are eugenol, eugenol, vanillin, 4-ethylphenol, cis-oakolactone, and trans-oakolactone. Ultrasonic waves have a mechanical breaking effect and a strong cavitation effect, which can accelerate the release and dissolution of solubilizing substances and ensure thorough mixing with the solvent, thereby improving extraction efficiency. This method offers advantages such as short extraction time, high efficiency, and mild conditions, and can be used to solubilize flavor compounds in oak chips. Compared to conventional ultrasonic extraction, this invention uses enhanced ultrasonic extraction, which can further enrich the pores of the barrel and promote the extraction of its active ingredients from the wine.

[0043] The actual and predicted values ​​of oak flavor content in whisky samples using Crisp malt and Raman yeast at different aging times were compared using the methods described in the aforementioned examples, as shown in Table 1.

[0044] Table 1 Actual and predicted values ​​of oak flavor content at different aging times

[0045]

[0046] Note: The average prediction accuracy is the average of the prediction accuracies for 1 month, 6 months, 12 months, and 36 months. As shown in Table 1, the prediction accuracy for flavor compounds aged in barrels for 1 month is 94.78%–106.92%; for 6 months, it is 92.40%–103.10%; for 12 months, it is 95.59%–102.21%; and for 36 months, it is 91.16%–104.06%. The results show that this model has good predictive ability for flavor compounds aged in barrels in both the short and long term.

Claims

1. A method for rapidly simulating the changes in oak flavour during the barrel ageing of alcoholic beverages, characterised in that, The content of oak flavor substances in barrel aging wine products at different aging stages is detected by using enhanced ultrasonic extraction combined with solid phase microextraction-gas chromatography mass spectrometry, so as to quickly predict the concentration range of oak flavor substances in actual wine products at different aging stages, wherein the enhanced ultrasonic extraction is as follows: 0.04 g of heavily carbonized oak wood chips is weighed and placed in a test bottle, 2 mL of ethanol / water is added, the volume ratio of ethanol to water is 60:40, pH is 5.5, 180 W ultrasonic power is used, the temperature is controlled to be less than 20 DEG C, and the ultrasonic time is set to be 20 s, 40 s, 80 s and 320 s in sequence; after ultrasonic extraction, the solution is filtered into a 20 mL headspace bottle, and then diluted to an ethanol concentration of less than or equal to 20%, which is used for subsequent solid phase microextraction-gas chromatography mass spectrometry analysis.

2. The method of claim 1, wherein, The oak flavor substances are syringaldehyde, eugenol, vanillin, 4-ethylphenol, cis-oak lactone and trans-oak lactone.

3. The method of claim 2, wherein, The simulation curve equation of the content of oak flavor substances at different aging stages of barrel aging wine products is established, and the simulation curve equation is as follows: Syringaldehyde: y = 966.82ln(x)-306.27; Eugenol: y = 31.975ln(x)-11.154; Vanillin: y = 203.91ln(x)-197.59; 4-ethylphenol: y = 0.279ln(x)-0.1092; Cis-oak lactone: y = 173.95ln(x)-0.8348; Trans-oak lactone: y = 117.51ln(x)-17.098; y is the oak flavor substance, and the unit is μg / L; x is the barrel aging days of simulation wine.

4. The method according to any one of claims 1 to 3, characterized in that, The prediction accuracy of flavor substances of barrel aging for 1 month is 94.78% to 106.92%; the prediction accuracy of flavor substances of barrel aging for 6 months is 92.40% to 103.10%; the prediction accuracy of flavor substances of barrel aging for 12 months is 95.59% to 102.21%; and the prediction accuracy of flavor substances of barrel aging for 36 months is 91.16% to 104.06%.

5. The method according to claim 1 or 2, characterized in that, The solid phase microextraction conditions are as follows: fiber extraction head: 65 µm DVB / CAR / PDMS extraction head; extraction temperature: 40 DEG C; pre-heat preservation time: 2 min; extraction time: 15 min; and analysis time: 3 min. The gas chromatography mass spectrometry conditions are as follows: a weak polarity capillary column 60 m x 0.32 mm x 0.25 µm is used, the carrier gas is nitrogen, the flow rate is 1.5 mL / min; the column temperature program is as follows: 35 DEG C is kept for 2 min, then increased to 60 DEG C at a rate of 7.5 DEG C / min and kept for 0.5 min, then increased to 240 DEG C at a rate of 15 DEG C / min and kept for 15 min; the injection port temperature is 250 DEG C; the electron impact energy is 70 eV; and the ion source temperature is 230 DEG C.

6. The method of claim 1 or 2, wherein, The standard mass spectrum library of the oak flavor substances is NIST standard mass spectrum library. ​ ​ ​ 7. The method of claim 6, wherein, ​

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