CN115372496A - Method for stabilizing volatile aroma substances of oolong tea and application - Google Patents
Method for stabilizing volatile aroma substances of oolong tea and application Download PDFInfo
- Publication number
- CN115372496A CN115372496A CN202210702304.7A CN202210702304A CN115372496A CN 115372496 A CN115372496 A CN 115372496A CN 202210702304 A CN202210702304 A CN 202210702304A CN 115372496 A CN115372496 A CN 115372496A
- Authority
- CN
- China
- Prior art keywords
- tea
- oolong tea
- aroma
- substances
- volatile aroma
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
- G01N30/02—Column chromatography
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
- G01N30/02—Column chromatography
- G01N30/04—Preparation or injection of sample to be analysed
- G01N30/06—Preparation
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
- G01N30/02—Column chromatography
- G01N30/62—Detectors specially adapted therefor
- G01N30/74—Optical detectors
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
- G01N30/02—Column chromatography
- G01N30/86—Signal analysis
- G01N30/8675—Evaluation, i.e. decoding of the signal into analytical information
- G01N30/8686—Fingerprinting, e.g. without prior knowledge of the sample components
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
- G01N30/02—Column chromatography
- G01N30/04—Preparation or injection of sample to be analysed
- G01N30/06—Preparation
- G01N2030/062—Preparation extracting sample from raw material
Landscapes
- Physics & Mathematics (AREA)
- Analytical Chemistry (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Library & Information Science (AREA)
- Engineering & Computer Science (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Tea And Coffee (AREA)
Abstract
The invention discloses a stabilizing method and application of volatile aroma substances of oolong tea. According to the invention, reduced glutathione is directly added into a water-based oolong tea product according to the addition amount of 25-1000 mg/L, the total VOC content of an oolong tea aroma SCC extract is increased by 40.6% after 42 days of storage, the total amount of volatile substances in tea soup is increased by 14% after 120 days of storage, so that the tea soup maintains the quality of 30 days of storage, the shelf life is prolonged by 90 days at the aroma level, and the GSH aroma-preserving method provided by the invention obviously reduces the loss of volatile aroma substances in water-based oolong tea products such as the oolong tea aroma extract and the tea soup product during the storage period.
Description
Technical Field
The invention belongs to the technical field of food processing, and particularly relates to a method for stabilizing volatile aroma substances of oolong tea and application thereof.
Background
The aroma is one of important quality factors of tea leaves and tea products, and has great influence on the consumer acceptance of the tea products. Meanwhile, with the development of plant aroma extraction technologies such as a rotating cone distillation tower and the like, tea aroma substances are also extracted and are widely applied to the food industry as natural plant essence. In the standard of 'tea sensory evaluation method' published in 2018, the percentage of the grading coefficient of the aroma factors on the evaluation of the tea is up to 25-35%, and the aroma is closely related to the quality of the tea and the tea related products. Tea aroma is mainly composed of Volatile Organic Compounds (VOCs). However, deterioration of aroma is one of the major problems in processing and storage of tea beverages and tea aroma extracts, and seriously affects the quality of tea products after storage. The bottom molecular mechanism of aroma deterioration is the content change of each VOCs composing the aroma of the product, and each VOC molecule is in the tea product matrix.
More than 700 flavor substances are separated from tea leaves so far, wherein the volatile aroma substances account for most of the tea leaves and mainly comprise alcohols, aldehydes, ketones, esters, acids, olefins, sulfur-containing compounds, nitrogen-containing compounds and the like. Currently, an important means of improving the retention and sustained release of volatile flavour substances in tea products is encapsulation. The purpose of encapsulation is to retain the flavour compounds, prevent oxidation reactions, and control the release of aroma components during product storage. For example, proteins (such as whey protein, soy protein, etc.) and polysaccharides (such as pectin, gum arabic, etc.) extracted from animals and plants as encapsulating agents in combination with complex coacervation technology have enabled the preparation of microcapsules of fragrances and essential oils. However, the research on aroma-keeping technology of water-based tea products is less, and some aroma-keeping methods for essence oil are not suitable for the tea water-based products. Aiming at products such as tea soup beverage, tea water-based natural plant essence and the like, the development of an effective aroma-preserving method is urgently needed to prolong the storage stability of easily consumed natural aroma components of the products on the premise of keeping natural aroma. Meanwhile, different tea varieties have different characteristic aroma substances, and oolong tea is one of the most aroma tea products, is commonly used for making beverages, milk tea and the like, and is also a main raw material of natural tea essence. The research aiming at the aroma-keeping technology of the oolong tea is not reported at present.
Reduced Glutathione (GSH), a tripeptide widely present in living bodies, has been applied to food, and is safe to food, and plays an important role in maintaining the physiological functions of cells, thus having certain health-care functions. GSH has-SH group and has certain reactivity with nucleophilic substances. Researches are carried out (food industry science and technology 38.08.2017, the influence of glutathione on aroma components of stored kiwi fruit and Tang wine; deng Xingxing, zhang Ying, liang Li, liu, ha Libi Asia & Yushan, jiang Ying. The influence of the addition amount of glutathione on the quality of Korla fragrant pear wine [ J ]. Chinese brewing, 2020,39 (11): 120-125.), and the influence mechanism of adding glutathione as a fermentation raw material in the fermentation process of fruit wine on the aroma of fruit wine is researched, wherein the influence mechanism is that the glutathione as a fermentation raw material influences the fermentation process of the fruit wine, so that the fruit wine and the change of aroma substances of the fruit wine during the storage period are adjusted. However, no report has been found on the research of applying GSH to the aroma protection of water-based foods.
Disclosure of Invention
Aiming at the problems in the prior art, the invention aims to provide an aroma-keeping method for inhibiting the loss of volatile aroma substances of an oolong tea water-based product during storage, innovatively utilizes reduced glutathione, and compared the effect with the effect of common tea product additives such as pectin and whey protein, the invention provides a method for protecting the volatile aroma substances of the water-based oolong tea product based on covalent combination of reduced glutathione and application thereof, so that the loss of the volatile aroma substances of the oolong tea water-based product during storage is effectively reduced, and the aroma quality stability of the product is remarkably improved.
In order to achieve the purpose, the invention is realized by the following technical scheme:
in one aspect, the present invention provides a method for stabilizing volatile aroma of oolong tea, which stabilizes volatile aroma of oolong tea in a water-based oolong tea product using a mercapto compound.
Further, the sulfhydryl compound is a compound which has food safety, is easy to dissolve in water and has sulfhydryl active groups, and the oolong tea volatile aroma substance is a water-based product of tea soup or tea aroma extract rich in oolong tea volatile aroma substances.
Further, the sulfhydryl compound is a biogenic sulfhydryl compound reduced glutathione.
Furthermore, the addition amount of the sulfhydryl compound is 25-1000mg per liter of volatile aroma substances of oolong tea.
Further, the mercapto compound and the volatile aroma substances of the oolong are mixed in a shaking or stirring mode, the temperature of the mixing reaction is controlled to be 4-100 ℃, the time of the mixing reaction is 2-20min, and the stirring speed is 0-200rpm.
Further, the oolong tea volatile aroma substances include (E) -2-pentenal, (E) -2-hexenal, 2-hexanone, 2-heptanone, 2-pentanone, butyraldehyde, butyl butyrate, and 2-methylbutan-1-ol, 2-methylpropanal, hexanal, 2-propanol, 2-methylbutyraldehyde, 3-pentanone, 2-ethyl-5-methylpyrazine, butyraldehyde, and α -pinene.
In another aspect, the invention provides the use of a mercapto compound to stabilize volatile aroma in an oolong tea water-based product.
Further, the sulfhydryl compound is a biogenic sulfhydryl compound reduced glutathione.
Further, the volatile aroma substances include (E) -2-pentenal, (E) -2-hexenal, 2-hexanone, 2-heptanone, 2-pentanone, butyraldehyde, butyl butyrate, and 2-methylbutan-1-ol, 2-methylpropanal, hexanal, 2-propanol, 2-methylbutyraldehyde, 3-pentanone, 2-ethyl-5-methylpyrazine, butyraldehyde, and α -pinene.
Compared with the prior art, the invention has the following beneficial effects:
1) Innovatively utilizes a mechanism of combining a sulfhydryl (-SH) group of reduced glutathione with specific and key aroma substances in an oolong tea water-based product to preserve aroma. The invention relates to a method for preparing a tea beverage, which is characterized in that different substances and a tea aroma extract rich in oolong volatile aroma substances are compounded, the inhibition effect of various substances on the loss degree of VOCs substances of tea leaves in the storage process under a water-based state is researched, and reduced glutathione is compared with system stabilizers such as pectin and whey protein and the like commonly used in beverages, so that the invention discloses a method for preparing a tea beverage by covalently combining the reduced glutathione with oolong aroma key substances.
2) The method has pertinence and excellent aroma-keeping effect on the oolong. The method has excellent aroma-keeping effect on oolong tea, and is remarkably superior to black tea; compared with black tea and the like, the oolong tea comprises key aroma substances of specific key aroma substances such as (E) -2-pentenal, (E) -2-hexenal, 2-hexanone, 2-heptanone, 2-pentanone, butyraldehyde, butyl butyrate and the like. The reduced glutathione remarkably inhibits the loss of tea aroma substances such as 2-methylbutan-1-ol, (E) -2-pentenal, 2-methylpropionaldehyde, (E) -2-hexenal, hexanal, 2-propanol, 2-hexanone, heptaldehyde, 2-methylbutanal, 2-heptanone, 3-pentanone, 2-ethyl-5-methylpyrazine, 2-pentanone, pentanal, butyraldehyde, butyl butyrate, alpha-pinene and the like in a water base during storage. Among them, the VOC substances with poor storage stability, heptanal, alpha-pinene, 2-heptanone, butyl butyrate, 2-methyl-1-butanol, butyraldehyde, hexanal, pentanal, etc. are included.
3) The method is simple, convenient and feasible, has strong industrial applicability, can add the reduced glutathione into the water-based tea product only by stirring, has low requirements on process and equipment, and has wide application prospect in the production of the existing tea water-based product.
4) The reduced glutathione is a biologically safe substance, is applied to food, has food safety, is a tripeptide consisting of glutamic acid, cysteine and glycine, is used as a physiological factor with wide effect, plays an important role in maintaining the physiological function of cells, and has a certain health-care function.
5) The reduced glutathione is directly applied to the aroma preservation of the water-based tea product for the first time, and the effect is obvious. After being treated by the glutathione aroma-maintaining method disclosed by the invention, the total VOC content of the SCC extract of the oolong tea aroma is increased by 40.6 percent after being stored for 42 days, wherein the total VOC content of the SCC extract is increased by more than 50 percent compared with that of an untreated group by 2-methylbutan-1-ol, 2-methyl-1-pentanol, heptanal, hexanal, 2-heptanone, 2-hexanone, 3-pentanone, pentanal, 2-pentanone, alpha-pinene, 2-methylbutanal, 2-propanol, butyl butyrate, dimethyl disulfide, hexanoic acid and butyraldehyde. The total amount of volatile substances in the tea soup is increased by 14% after 120 days of storage, so that the tea soup maintains the quality of 30 days of storage, and the shelf life is prolonged by 90 days at the aroma level. Specifically, after the tea soup is stored for 120 days, the contents of 2-ethyl-5-methylpyrazine, benzaldehyde, heptaldehyde, 2-heptanone, (E) -2-hexenal, hexanal and ethyl butyrate are respectively 2.9 times, 5.81 times, 2.67 times, 6.09 times, 3.47 times, 1.54 times and 2.61 times of the contents of the control group in terms of volatile substances which are easy to lose. Therefore, the GSH aroma-keeping method of the invention obviously reduces the loss of volatile aroma substances in water-based oolong tea products such as oolong tea aroma extract, tea soup products and the like during storage.
Drawings
FIG. 1: VOC fingerprint during storage of cinnamon oolong SCC extract;
FIG. 2: heat map of VOC content change during storage of cinnamon oolong SCC extract;
FIG. 3: a heat map of VOC content change of cinnamon oolong SCC extract under the treatment of reduced glutathione G, pectin P and whey protein W;
FIG. 4 is a schematic view of: after the cinnamon oolong SCC extract is stored for 42 days under the treatment of reduced glutathione G, pectin P and lactalbumin W, the total VOC content is increased;
FIG. 5: analyzing the main components of SCC extract of cinnamon oolong tea which is treated by reduced glutathione G, pectin P and lactalbumin and changes in 21 days (left) and 42 days (right) of storage;
FIG. 6: and (3) performing orthogonal partial least squares discriminant analysis (OPLS-DA) on SCC extract VOC change of cinnamon oolong under reduced glutathione treatment. The left graph is an OPLS-DA score map; the right figure is a VIP-plot;
FIG. 7 is a schematic view of: reduced glutathione on VOC composition change heat map of cinnamon oolong and Yunnan black tea SCC extracts;
FIG. 8: fourier infrared absorption spectrum of covalent combination of reduced glutathione and key volatile flavor substances.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention are clearly and completely described below with reference to the drawings and the specific embodiments of the specification.
Example 1: preparation of tea samples
Cinnamon ZWO-20-002 (cinnamon oolong tea), yunnan congou BT2136 (Yunnan black tea), and tea raw materials are added into a rotary cone distillation tower to prepare a product for extracting tea volatile aroma substances SCC, wherein the technological parameters of the rotary cone distillation tower are set as shown in the following table 1. The obtained water-based colorless tea volatile aroma substance SCC extraction product is used for a subsequent tea aroma volatile substance aroma-keeping experiment.
Example 2: aroma preserving treatment
The following 4 different substances are adopted to carry out aroma-keeping treatment on the tea volatile aroma substance SCC extracted product according to the concentration commonly used in the production.
Reduced glutathione (glutathione) is produced by Shanghai Michelin Biochemical technology Ltd and has a purity of 0.98. 200mL of the SCC extract was added with 0.1g of reduced glutathione, and stirred for 5min to ensure complete dissolution of the reduced glutathione.
Pectin (Pectin) is produced by Shanghai gold ear Biotech limited, is apple-derived, and has a high methoxyl content of 65%. 200mL of SCC extract was added with 0.5g of pectin and stirred at 90 ℃ for 5min to ensure complete dissolution of the pectin.
Whey protein (Bovine-hey) was produced by Shanghai Aladdin Biotechnology, inc. 200mL of the SCC extract was added with 20.0g of whey protein, and stirred for 5min to ensure complete dissolution of the whey protein.
Example 3
The SCC extract of tea leaves treated by the aroma-retention agent or not is subpackaged into 15mL of clean and sterile test tubes, and each tube is subpackaged with 12mL of SCC extract. Storing in a shady and cool place at the room temperature of 25 ℃ to avoid the sunshine.
Taking 2mL of SCC extract of tea leaves stored for a certain time and added with or without a fragrance preserving agent, diluting 50 μ L of internal standard solution with distilled water to 20mL, and mixing uniformly. 5mL of the solution to be tested was added to each sample bottle, and 3 sets of replicates were set for each sample. The preparation method of the internal standard used for 2-Octanol (2-Octanol) comprises the following steps: taking 10mg of 2-octanol, using purified water to fix the volume to 10mL, and storing in a refrigerator at 2-4 ℃ for later use. The 2-octanol was purchased from Shanghai Anpu scientific Co., ltd, and had a standard value of 99.4% and an uncertainty of 2.0%.
The volatile substances in the sample are determined by gas phase-ion mobility spectrometry (GC-IMS).
And (3) setting GC-IMS parameters:
headspace sampling conditions-incubation temperature: at 40 ℃; incubation time: 15min; hatching rotating speed: 500rpm, sample volume: 0.5mL;
GC gas chromatography conditions-column type: MXT-5 (15 m. Times.0.53 mm. Times.1 μm) column temperature: 60 ℃; carrier gas: n2, the purity is more than 99.999 percent; flow rate of carrier gas: 0-2min, 2mL/min; 2-10 min, 2-10 mL/min; 10-20min, 10-100 mL/min; 20-30min, 100-150 mL/min;
IMS ion mobility mass spectrometry conditions-linear voltage in tube: 400V/cm; flying gas: n2, the purity is more than 99.999 percent; flow rate: 150mL/min; temperature: at 45 ℃.
GC-IMS result processing: performing GC-IMS result processing by using GC-IMS matched analysis software LAV (Laboratory Analytical Viewer), and performing substance qualification of response peak through two dimensions of migration time and retention time by using a NIST database and an IMS database which are built in a GC-IMS Library Search; using a GC-IMS plug-in Gallery Plot to draw a fingerprint map and a difference map; peak volumes of framed ion response peaks were obtained using the Quantification-Run function built into LAV.
Example 4
Dissolving 1.8mmol of reduced glutathione in 6mL of 0.05% dimethyl sulfoxide solution, adding 200 muL of 2-ethyl-5-methylpyrazine after complete dissolution, uniformly stirring at 25 ℃ for 45min, and freeze-drying the obtained product in vacuum for 24h at-73 ℃ in a cold trap and 0.8Pa in vacuum degree.
Dissolving 1.8mmol of reduced glutathione in 6mL of 0.05% dimethyl sulfoxide solution, adding 1.8mmol of trans-2-hexenal after complete dissolution, uniformly stirring at the stirring temperature of 25 ℃ for 45min, and freeze-drying the obtained product in vacuum for 24h at the cold trap temperature of-73 ℃ and the vacuum degree of 0.8Pa.
Dissolving 1.8mmol of reduced glutathione in 6mL of 0.05% dimethyl sulfoxide solution, adding 200 mu L of alpha-pinene after complete dissolution, uniformly stirring at the stirring temperature of 25 ℃ for 45min, and freeze-drying the obtained product in vacuum for 24h at the cold trap temperature of-73 ℃ and the vacuum degree of 0.8Pa.
Dissolving 1.8mmol of reduced glutathione in 6mL of 0.05% dimethyl sulfoxide solution, adding 200 mu L of hexanal after complete dissolution, uniformly stirring at the temperature of 25 ℃ for 45min, and freeze-drying the obtained product in vacuum for 24h at the temperature of-73 ℃ in a cold trap and the vacuum degree of 0.8Pa.
Dissolving 1.8mmol of reduced glutathione in 6mL of 0.05% dimethyl sulfoxide solution, adding 200 mu L of 2-methyl butyraldehyde after complete dissolution, uniformly stirring at 25 ℃ for 45min, and freeze-drying the obtained product in vacuum for 24h at-73 ℃ in a cold trap and 0.8Pa in vacuum degree.
And performing Fourier infrared absorption spectrum analysis on the reaction product, and comparing with Fourier infrared absorption spectra of 2-ethyl-5-methylpyrazine, alpha-pinene, hexanal, 2-methylbutyraldehyde, trans-2-hexenal pure products and physical mixed samples of the volatile flavor substances and the reduced glutathione respectively.
Example 5: tea soup beverage aroma substance detection
The tea soup beverage is prepared by adopting the following compounding method: cinnamon oolong (6 kg of tea soup, 9kg of water, pH 5.34), hot-filling after compounding. The tea soup sample was subjected to the aroma-retaining treatment using the reduced glutathione aroma-retaining treatment in example 2, and both the treated sample (GSH group) and the untreated group (CK vs. illumination) were stored at 25 ℃ in the dark, and samples were periodically taken. The volatile substances in the sample are determined by gas phase-ion mobility spectrometry (GC-IMS).
And (3) setting GC-IMS parameters: headspace sampling conditions-incubation temperature: 40 ℃; incubation time: 15min; hatching rotating speed: 500rpm, sample volume: 0.5mL;
GC gas chromatography conditions-column type: MXT-5 (15 m. Times.0.53 mm. Times.1 μm) column temperature: 60 ℃; carrier gas: n2, the purity is more than 99.999 percent; flow rate of carrier gas: 0-2min, 2mL/min; 2-10 min, 2-10 mL/min; 10-20min, 10-100 mL/min; 20-30min, 100-150 mL/min;
IMS ion mobility mass spectrometry conditions-linear voltage in tube: 400V/cm; flying gas: n2, the purity is more than 99.999 percent; flow rate: 150mL/min; temperature: at 45 ℃.
GC-IMS result processing: performing GC-IMS result processing by using GC-IMS matched analysis software LAV (Laboratory Analytical Viewer), and performing substance qualification of response peak through two dimensions of migration time and retention time by using a NIST database and an IMS database which are built in a GC-IMS Library Search; drawing a fingerprint map and a difference map by using a GC-IMS plug-in Gallery Plot; peak volumes of framed ion response peaks were obtained using the quantum-Run function built into LAV.
Determination of results
In order to observe the VOC change during storage of the cinnamon oolong SCC extract, in example 3, the fingerprint of the cinnamon oolong SCC extract was measured by GC-IMS (fig. 1), and it was found that as the storage time progressed, most of the VOC peak response intensity gradually decreased (as a portion was selected from the sixth frame from left to right), and a small portion of the VOC peak response intensity gradually increased (as a portion was selected from the third frame from left to right), indicating that most of the aroma substances in cinnamon oolong were poor in storage stability. Through quantitative analysis of each VOC component, the heat map (figure 2) shows that the relative content of more substances in cinnamon oolong tea is reduced along with the storage time, and is consistent with the result reflected by the fingerprint. Wherein the average loss of 6 aroma substances in the storage period is more than 50 percent, and the aroma substances are respectively 2-methyl-1-pentanol, heptanal, hexanoic acid, alpha-pinene, 2-heptanone and butyl butyrate. In addition, the average loss of 2-methyl-1-butanol, butyraldehyde, hexanal, pentanal exceeds 20%. The results indicate that loss of these substances may be the primary cause of aroma loss during storage of cinnamon oolong tea.
In example 3, reduced glutathione, pectin, and whey protein were compared for differences in flavor retention effects on SCC extract of cinnamon oolong tea in order to screen suitable flavor retention substances. From the heat map (fig. 3), it was found that reduced glutathione G had a good treatment effect and was effective in reducing the loss of most of the fragrance components, and 2-methylbutan-1-ol, 2-methyl-1-pentanol, heptanal, hexanal, 2-heptanone, 2-hexanone, 3-pentanone, pentanal, 2-pentanone, α -pinene, 2-methylbutanal, 2-propanol, butyl butyrate, dimethyl disulfide, hexanoic acid, and butanal were more than 50% higher than those in the untreated group after 42 days of storage. As shown in fig. 5, compared with the total VOC content after 42 days of storage, the total VOC content of the SCC extract of oolong tea aroma was increased by 40.6% (fig. 4) after 42 days of storage, and the aroma quality was significantly improved. Whey protein treatment was less effective, while pectin treatment was less effective. The main component analysis shows that after 21 days of storage, each treatment group (21-G, 21-P, 21-W) and the untreated group (21-CK) are obviously separated from the sample on the 0 th day, and each treatment group is also obviously separated, which shows that each treatment has a significant influence on the storage component change of the cinnamon oolong tea. Wherein, compared with the W group (21-W) and the P group (21-P), the G group (21-G) is separated from the sample on the 0 th day to a smaller extent, which shows that the G group is closer to the component change trend of the sample on the 0 th day than other treatment groups, and shows obvious fragrance-keeping effect. The P group (21-P) was less separated from the CK group after 21 days of storage, indicating that P treatment had less effect on the change in storage composition of the samples. Similarly, the same phenomenon was observed after 42 days of storage. In conclusion, the aroma-keeping effect of the reduced glutathione treatment on cinnamon oolong is better than that of pectin and whey protein.
In order to identify key substances of reduced glutathione on flavor retention of cinnamon oolong SCC extract, in example 3, orthogonal partial least squares discriminant analysis (OPLS-DA) was performed, and it was found that the larger the VIP value, the larger the contribution to the model. As can be seen from FIG. 6, there are 17 substances with VIP greater than 1, namely 2-methylbutan-1-ol, (E) -2-pentenal, 2-methylpropionaldehyde, (E) -2-hexenal, hexanal, 2-propanol, 2-hexanone, heptaldehyde, 2-methylbutanal, 2-heptanone, 3-pentanone, 2-ethyl-5-methylpyrazine, 2-pentanone, valeraldehyde, butyraldehyde, butyl butyrate and alpha-pinene. After the reduced glutathione treatment, except that the contents of (E) -2-pentenal, (E) -2-hexenal and 2-ethyl-5-methylpyrazine are reduced, the contents of other 14 substances are increased, and the 14 substances comprise substances with poor storage stability, such as heptanal, alpha-pinene, 2-heptanone, butyl butyrate, 2-methyl-1-butanol, butyraldehyde, hexanal and valeraldehyde. It is shown that reduced glutathione may achieve the effect of preserving fragrance by increasing or slowing the loss of these substances.
To verify the pertinence of the reduced glutathione aroma-preserving method to the SCC extract of cinnamon oolong tea, in example 3, the aroma-preserving effects of reduced glutathione on cinnamon oolong and Yunnan black tea were compared. As can be seen from the graph 7, the reduced glutathione treatment can better slow down or improve the content of most of the components of the cinnamon oolong, but has no obvious effect of slowing down or improving the aroma components of the Yunnan black tea, and even reduces the content of most of the aroma components after 42 days of storage. Most key substances of the reduced glutathione for flavor protection of cinnamon oolong belong to specific components of cinnamon oolong, and comprise (E) -2-pentenal, (E) -2-hexenal, 2-hexanone, 2-heptanone, 2-pentanone, butyraldehyde and butyl butyrate. The results show that the reduced glutathione has specificity on the fragrance-keeping effect of cinnamon oolong tea.
In order to investigate the aroma-maintaining effect of reduced glutathione on oolong tea soup during storage, in example 5, the change of volatile substances in oolong tea soup beverage after storage at normal temperature for various periods of time was examined, and as shown in table 2, tea SCC extract is an enriched water-based product of tea volatile aroma, and in comparison, since the VOC concentration in tea soup product is desired to be relatively low, the volatile substance component detected in tea soup is less than that in tea volatile aroma SCC extract product. As can be seen from table 2, volatile substances in the tea soup decreased with the increase of the number of days of storage, and thus it was seen that the loss of volatile substances during storage was a main cause of deterioration of the flavor of the tea soup product. The volatile flavor substances easy to lose comprise 2-ethyl-5-methylpyrazine, benzaldehyde, heptaldehyde, 2-heptanone, (E) -2-hexenal, hexanal, ethyl butyrate and the like, and the main loss components of the volatile flavor substances are similar to the substances easy to lose in a tea fragrance SCC extraction product. After the glutathione aroma-preserving method is adopted to treat the tea soup, the total amount of volatile substances in the tea soup after being stored for 120 days is obviously higher than that of a control group, and the total amount is improved by 14 percent. After the volatile substances which are easy to lose are subjected to aroma-keeping treatment of reduced Glutathione (GSH), and are stored for 120 days, the contents of 2-ethyl-5-methylpyrazine, benzaldehyde, heptaldehyde, 2-heptanone, (E) -2-hexenal, hexanal and ethyl butyrate are respectively 2.9 times, 5.81 times, 2.67 times, 6.09 times, 3.47 times, 1.54 times and 2.61 times of the content of a control group. Therefore, the GSH aroma-keeping method of the invention remarkably reduces the loss of volatile aroma substances in the tea soup product during storage.
In order to investigate the mechanism of fragrance retention of reduced glutathione on the volatile aroma substances of oolong tea, in example 4, the interaction relationship between these VOC substances and reduced glutathione was investigated using 2-ethyl-5-methylpyrazine, α -pinene, hexanal, 2-methylbutanal, trans-2-hexenal as typical representatives of the volatile substances in oolong tea that are severely lost during storage. The Fourier infrared spectrum of the reaction product of the 5 volatile substances and the reduced glutathione and the Fourier infrared absorption spectrum of the pure products of the 2-ethyl-5-methylpyrazine, the alpha-pinene, the hexanal, the 2-methylbutyraldehyde and the trans-2-hexenal and the physically mixed samples of the volatile flavor substances and the reduced glutathione are shown in FIG. 8.
The characteristic peak wave number of the VOC is in the range of 2725-3025cm as shown in FIG. 8 -1 The experimental results show that the addition reaction can give signals of characteristic peaks of VOC molecules such as 2-ethyl-5-methylpyrazine, alpha-pinene, hexanal, 2-methylbutyraldehyde and trans-2-hexenalWeakening; the mercapto wave number of GSH is 2600-2540cm -1 The signal of this characteristic peak of glutathione is attenuated by the addition reaction. In conclusion, it is concluded that the VOC molecule reacts with the thiol group of glutathione, further confirming the progress of the interaction reaction. Thus, a review of reduced glutathione dissolved in water has shown that it interacts covalently with volatile aroma VOC molecules in water-based oolong tea products, thereby increasing the stability and retention of the VOC molecules during storage.
In conclusion, the invention provides a method for protecting volatile aroma substances of a water-based oolong tea product based on reduced glutathione covalent bonding and application thereof, reduced glutathione is directly applied to aroma preservation of the water-based oolong tea product for the first time, so that the loss of the volatile aroma substances of the water-based oolong tea product during storage is effectively reduced, the aroma quality stability of the product is remarkably improved, and the technology breaks through the key technical bottleneck that the aroma is easy to deteriorate and lose in tea processing.
After the glutathione aroma-preserving method disclosed by the invention is adopted for treatment, the total VOC content of the SCC extract of the oolong aroma is improved by 40.6% after the SCC extract is stored for 42 days, wherein 2-methylbutan-1-ol, 2-methyl-1-pentanol, heptanal, hexanal, 2-heptanone, 2-hexanone, 3-pentanone, pentanal, 2-pentanone, alpha-pinene, 2-methylbutanal, 2-propanol, butyl butyrate, dimethyl disulfide, caproic acid and butyraldehyde are higher than those in an untreated group by more than 50%. The total amount of volatile substances in the tea soup after 120 days of storage is improved by 14 percent, so that the tea soup maintains the quality of 30 days of storage, and the shelf life is prolonged by 90 days on the aspect of aroma. Specifically, after the tea soup is stored for 120 days, the contents of 2-ethyl-5-methylpyrazine, benzaldehyde, heptaldehyde, 2-heptanone, (E) -2-hexenal, hexanal and ethyl butyrate are respectively 2.9, 5.81, 2.67, 6.09, 3.47, 1.54 and 2.61 times of those of a control group.
Therefore, the GSH aroma-keeping method of the invention obviously reduces the loss of volatile aroma substances in water-based oolong tea products such as oolong tea aroma extract and tea soup products during storage.
TABLE 2 changes in volatile substances after different storage periods
Claims (9)
1. A method for stabilizing volatile aroma substances of oolong tea, characterized in that the method stabilizes volatile aroma substances of oolong tea in a water-based oolong tea product by using a mercapto compound.
2. The method for stabilizing oolong tea volatile aroma substances as claimed in claim 1, wherein the mercapto compound is a compound having a mercapto active group which is food safe, easily soluble in water, and the oolong tea volatile aroma substances are water-based products of tea soup or tea aroma extract rich in oolong tea volatile aroma substances.
3. The method for stabilizing volatile aroma of oolong tea as claimed in claim 2, wherein the mercapto compound is a bio-derived mercapto compound reduced glutathione.
4. The method for stabilizing volatile aroma of oolong tea as claimed in any one of claims 1 to 3, wherein the mercapto compound is added in an amount of 25 to 1000mg per liter of volatile aroma of oolong tea.
5. The method for stabilizing volatile aroma of oolong tea as claimed in claims 1 to 3, wherein the mercapto compound and the volatile aroma of oolong tea are mixed by shaking or stirring, the temperature of the mixing reaction is controlled to 4 to 100 ℃, the time of the mixing reaction is 2 to 20min, and the stirring speed is 0 to 200rpm.
6. The method for stabilizing volatile aroma of oolong tea as claimed in claim 1, wherein the volatile aroma of oolong tea comprises (E) -2-pentenal, (E) -2-hexenal, 2-hexanone, 2-heptanone, 2-pentanone, butyraldehyde, butyl butyrate and 2-methylbutan-1-ol, 2-methylpropanal, hexanal, 2-propanol, 2-methylbutanal, 3-pentanone, 2-ethyl-5-methylpyrazine, butyraldehyde and α -pinene.
7. Use of a mercapto compound to stabilise volatile aroma substances in an oolong tea water based product.
8. The use according to claim 7, characterized in that the sulfhydryl compound is a biogenic sulfhydryl compound, reduced glutathione.
9. Use according to claim 7, characterized in that the volatile aroma substances comprise (E) -2-pentenal, (E) -2-hexenal, 2-hexanone, 2-heptanone, 2-pentanone, butyraldehyde, butyl butyrate and 2-methylbutan-1-ol, 2-methylpropanal, hexanal, 2-propanol, 2-methylbutyraldehyde, 3-pentanone, 2-ethyl-5-methylpyrazine, butyraldehyde and α -pinene.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210702304.7A CN115372496A (en) | 2022-06-21 | 2022-06-21 | Method for stabilizing volatile aroma substances of oolong tea and application |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210702304.7A CN115372496A (en) | 2022-06-21 | 2022-06-21 | Method for stabilizing volatile aroma substances of oolong tea and application |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115372496A true CN115372496A (en) | 2022-11-22 |
Family
ID=84061821
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210702304.7A Pending CN115372496A (en) | 2022-06-21 | 2022-06-21 | Method for stabilizing volatile aroma substances of oolong tea and application |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115372496A (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1529554A (en) * | 2001-03-23 | 2004-09-15 | �Ʒ� | Improvement of aroma-containing components |
| CN105707300A (en) * | 2016-02-19 | 2016-06-29 | 湖南农业大学 | Dendrobium associated black tea and drink resisting haze and processing method and application thereof |
| CN114166955A (en) * | 2021-09-17 | 2022-03-11 | 福建农林大学 | Analysis method for influence of storage time on quality of Fotiaoqiang |
-
2022
- 2022-06-21 CN CN202210702304.7A patent/CN115372496A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1529554A (en) * | 2001-03-23 | 2004-09-15 | �Ʒ� | Improvement of aroma-containing components |
| CN1635839A (en) * | 2001-03-23 | 2005-07-06 | 雀巢制品公司 | Stabilization of aroma-providing components |
| CN105707300A (en) * | 2016-02-19 | 2016-06-29 | 湖南农业大学 | Dendrobium associated black tea and drink resisting haze and processing method and application thereof |
| CN114166955A (en) * | 2021-09-17 | 2022-03-11 | 福建农林大学 | Analysis method for influence of storage time on quality of Fotiaoqiang |
Non-Patent Citations (2)
| Title |
|---|
| 戚一曼;程拯艮;樊明涛;: "谷胱甘肽添加对贮藏猕猴桃酒香气成分的影响", 食品工业科技, no. 08, pages 183 - 188 * |
| 王梦琪 等: "茶叶挥发性成分中关键呈香成分研究进展", 食品科学, vol. 40, no. 23, pages 341 - 349 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Lan et al. | Characterization and differentiation of key odor-active compounds of ‘Beibinghong’icewine and dry wine by gas chromatography-olfactometry and aroma reconstitution | |
| Margalit | Concepts in wine chemistry | |
| Ayaz et al. | Sugar, non-volatile and phenolic acids composition of strawberry tree (Arbutus unedo L. var. ellipsoidea) fruits | |
| Crandles et al. | The effect of yeast strain on odor active compounds in Riesling and Vidal blanc icewines | |
| Luo et al. | Effect of glucose oxidase treatment on the aroma qualities and release of cooked off-odor components from heat-treated Hami melon juice | |
| Yi et al. | Comparison of different extraction methods in the analysis of volatile compounds in pomegranate juice | |
| CN113444577A (en) | Extraction method and application of rose cell water and rose essential oil | |
| Gallardo-Chacón et al. | Sorption of 4-ethylphenol and 4-ethylguaiacol by suberin from cork | |
| CN112156049A (en) | Plant hydrolat and preparation method thereof | |
| Hashim et al. | Effect of pH on adsorption of organic acids and phenolic compounds by amberlite ira 67 resin | |
| CN114806904B (en) | Functional microorganism and preparation method and application thereof | |
| Jiménez-Martínez et al. | Performance of purified grape pomace as a fining agent to reduce the levels of some contaminants from wine | |
| CN115372496A (en) | Method for stabilizing volatile aroma substances of oolong tea and application | |
| KR20100007766A (en) | Increased stability of flavor compounds | |
| CN102495147B (en) | Method for detecting and improving main adverse flavor of red bayberry fruit juice | |
| Sommano et al. | Measurement of ascorbic acid in Australian native plants | |
| TWI631903B (en) | Plant extract from monomeric proanthocyanidins | |
| CN103815010B (en) | GABA delay citrusfruit adopt after application in anaerobic digestion | |
| Dang et al. | Removal of Cu (II) by ion exchange resin and its re-utilization of the residual solution from the distilled Lycium barbarum wine | |
| CN116195733B (en) | Composite deodorization method for reducing earthy smell of bamboo fungus | |
| CN112410142B (en) | Method for preparing functional food with high content of polyphenol compounds by using fermented hops | |
| Zhao et al. | Effects of different pectinase maceration pre-treatments on physicochemical properties of raspberry juice and wine. | |
| JP5322602B2 (en) | Method for producing anti-ice nuclear activator | |
| JP5757676B2 (en) | Method for increasing the stability of perfume compounds | |
| CN114402922A (en) | Application and method of inositol and preparation in fruit and vegetable fresh-keeping and/or improving fruit and vegetable storage resistance |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |