CN117179085A

CN117179085A - Perilla tea and processing method and application thereof

Info

Publication number: CN117179085A
Application number: CN202311121382.9A
Authority: CN
Inventors: 沈奇; 王宏斌; 马中华; 梁梓珊
Original assignee: Guangzhou University of Traditional Chinese Medicine
Current assignee: Guangzhou University of Traditional Chinese Medicine
Priority date: 2023-08-31
Filing date: 2023-08-31
Publication date: 2023-12-08

Abstract

The invention discloses a processing method of perilla tea. The processing method comprises the following steps: s1, withering: spreading and withering fresh leaf buds of the purple perilla to obtain purple perilla withered leaves; s2, twisting: rolling the perilla withered leaves; deblocking; fermentation: fermenting the perilla leaves in a ventilation environment to obtain perilla fermentation leaves; s5, drying: and (3) drying the fermented leaves of the purple perilla to obtain the purple perilla tea. The invention takes the fresh leaves of the purple perilla as the raw material, has strong aroma of the purple perilla, is rich in rosmarinic acid and anthocyanin substances, and has the effects of releasing exterior and dispelling cold, reminding people to refresh the brain, reducing dryness and removing greasiness, and the like. In addition, the invention improves the micro-fermentation process, so as to maximally retain the effective components in the purple perilla and improve the flavor of the purple perilla. The invention provides the perilla tea which is rich in antioxidant active ingredients and has strong aroma and special flavor.

Description

Perilla tea and processing method and application thereof

Technical Field

The invention belongs to the technical field of tea processing, and particularly relates to perilla tea, and a processing method and application thereof.

Background

Perilla is a annual herb medicine and food dual purpose plant, has a cultivation history of over 2000 in China, and has resource distribution in over 20 provinces in China. Perilla has effects of relieving exterior syndrome, dispelling cold, promoting qi circulation, regulating stomach function, promoting urination, removing toxic substances, etc., and has strong fragrance, and can be used as spice, vegetable, and pickle for people in folk, and has good health promotion effect. The different perilla contains active substances with larger difference, wherein the main component of the volatile oil in the medicinal perilla is perillaldehyde, and the medicinal perilla has the activities of relieving exterior syndrome, resisting aging, resisting oxidation, resisting depression and the like. It also contains higher Perilla flavonoids, and has antioxidant, antiinflammatory, antiallergic and blood glucose and blood lipid regulating pharmacological activities. In addition, the medicinal perilla contains abundant rosmarinic acid which is used as a natural antioxidant and has obvious physiological activities of resisting aging, resisting bacteria, diminishing inflammation, resisting tumors and the like.

At present, students identify the volatile components of perilla in different harvesting periods, and identify 52 volatile components, wherein 20 volatile components are butyraldehyde, acetic acid, mushroom alcohol, linalool, 3, 5-trimethylcyclohexane, perillyl ketone, beta-ionone, beta-elemene, bergamotene, beta-caryophyllene (beta-caryophyllene), lupulone, alpha-aragonine, trans-farnesene, beta-lawrene, alpha-caryophyllene, alpha-bergamotene, alpha-farnesene, D-germacrene, nutmeg ether, nerolidol and apigenin. In addition, the chemical composition and biological activity of the extracted perilla essential oil were analyzed by a learner, and the result showed that the main compounds were carvone (32.55%), perillaldehyde (20.52%), caryophyllene (9.85%), 2-furanmethylketone (7.53%), 2, 6-dimethyl-6- (4-methyl-3-pentenyl) -4-norbenne (5.17%), and beta-terpineyl acetate (3.41%).

Patent CN110590526a discloses a method for extracting perillaldehyde from perilla, which comprises the following steps: pretreatment, acidification enzymolysis, primary treatment of enzyme, secondary treatment, extraction, decolorization, impurity removal, reduced pressure distillation and deodorization purification. The method remarkably improves the quality and the utilization rate of the perillaldehyde, improves the extraction rate, simultaneously keeps the chemical property of the perillaldehyde to the maximum extent, greatly reduces the introduction and the residue of organic reagents, and improves the purity and the quality of the perillaldehyde finished product. However, the extraction rate of the perillaldehyde obtained by the method is only 24.76%, and the content of the perillaldehyde and other volatile oil components is low; in addition, the content of flavonoids, rosmarinic acid, caffeic acid and other substances obtained by the method is low; and because of less active ingredients, the prepared perilla tea also lacks intense fragrance and special flavor, and is difficult to meet the actual demands.

Disclosure of Invention

Aiming at the prior art problems, the primary aim of the invention is to provide a processing method of perilla tea, which adopts the methods of moderate withering, rolling, fermenting and the like of perilla to promote the conversion and release of volatile oil, polyphenol, flavonoid and other aromatic substances of the perilla, thereby reducing the bitter taste of the perilla, enhancing the release of aromatic substances of perilla leaves, improving the fragrance quality and mellow taste, and maximally retaining the main active substances and fragrance quality in the perilla leaves. Finally, the micro-fermented perilla tea which is rich in antioxidant active ingredients and has strong aroma and special flavor is formed.

The second aim of the invention is to provide the perilla tea prepared by the processing method of the perilla tea.

The third object of the invention is to provide the application of the perilla tea in preparing antioxidant products.

The fourth object of the present invention is to provide a perilla tea composition comprising: the above Perillae herba tea and black tea.

In order to achieve the above object, the present invention is realized by the following technical scheme:

a processing method of perilla tea comprises the following steps:

s1, withering: spreading and withering fresh leaf buds of the purple perilla to obtain purple perilla withered leaves;

s2, twisting: twisting the perilla withered leaves in the step S1;

s3, deblocking: deblocking the perilla leaves rolled in the step S2;

s4, fermenting: fermenting the perilla leaves subjected to deblocking in the step S3 in a ventilation environment to obtain perilla fermentation leaves;

s5, drying: and (3) drying the perilla fermented leaves in the step (S4) to obtain the perilla tea.

The invention takes medicinal fresh leaves of perilla as raw materials, and the monoterpene component in the perilla volatile oil mainly takes perillaldehyde as a main component. The Perillae herba has strong fragrance, is rich in rosmarinic acid and anthocyanin substances, and has effects of relieving exterior syndrome, dispelling cold, promoting refreshment, and reducing dryness and greasiness.

On the basis, the invention improves the micro-fermentation process, maximally reserves the functional components in the purple perilla, improves the flavor of the purple perilla, and finally forms the purple perilla tea which is rich in antioxidant active components and has strong fragrance and flavor characteristics. Specifically, the invention can promote the hydrolysis of the self protein substances and polysaccharide substances of the purple perilla and the volatilization of the low-boiling-point green grass smell by controlling the withering degree, and meanwhile, the stem leaves are uniform in water passing, so that the invention is beneficial to rolling and the formation of tea quality. And the rolling can promote the cells to be fully broken, which is favorable for the formation and volatilization of the aroma. The rolling can improve the cell disruption degree of the perilla leaves, and the leaves are in extrusion contact with each other in the rolling process, so that juice is mutually infiltrated. The fermentation process can promote enzymatic reaction and material hydrolysis, especially oxidation of phenols, hydrolysis of polysaccharides and formation of aromatic substances, which lay a foundation for reducing bitter and astringent taste of Perilla frutescens and forming high-efficiency and durable tea fragrance with special Perilla frutescens function. Finally, the purple perilla is subjected to rough fire treatment, and moisture is quickly evaporated in a short time at a high temperature, so that the green grass smell of wet tea can be volatilized, and the aroma of the purple perilla can be more reserved; and then carrying out sufficient fire treatment, and slowly baking with slow fire to form the natural purple perilla functional tea with cool sense, namely the aroma quality and the mellow taste quality of the purple perilla functional tea.

Compared with common perilla tea, the perilla tea provided by the invention is rich in perillaldehyde, and the contents of caryophyllene, nerolidol, eucalyptol, longifolene, phytol and other substances in volatile components are higher than those of the common perilla tea. The content of rosmarinic acid, caffeic acid, flavone and anthocyanin in the perilla tea provided by the invention is obviously increased. The micro-fermentation processing technology promotes the conversion of substances in the perilla tea and enhances the health care function of the perilla tea. And the perilla tea has stronger antioxidation capability and has the same antioxidation activity as common black tea under high concentration as the perilla tea is selected and processed. According to the component evaluation result, the quality control standard of the perilla tea is defined as: the content of perillaldehyde is not less than 40% of volatile oil; the rosmarinic acid content is not less than 1mg/g; the total flavone content is not less than 1.5mg/g; the anthocyanin content is not less than 0.5mg/g. The perilla tea provided by the invention not only has strong aroma and special flavor, but also has stronger antioxidation capability, and the antioxidation activity of the perilla tea is equivalent to that of common black tea at high concentration.

Preferably, in the step S1, the moisture content of the perilla withered leaves is controlled to be 50-60%.

Preferably, in the step S1, the spreading withering is spreading under natural conditions; or spreading and withering under the conditions that the temperature is 20-30 ℃ and the humidity is 60-80%. When the withering temperature is controlled in the range, the content of polyphenols and amino acids in the perilla leaves is gradually increased, the volatilization of aromatic substances is less, and the aroma of the finished product is high.

Preferably, in the step S2, the temperature is controlled to be 22-30 ℃ and the humidity is controlled to be 60-80%.

Further preferably, in the rolling process, the rolling pressure can be classified into light pressure, medium pressure or heavy pressure according to a time gradient, and the rolling time is 60-90 min.

Preferably, in the step S4, the fermentation treatment is fermentation under natural conditions; or the fermentation treatment is carried out under the conditions that the temperature is 22-30 ℃ and the humidity is 80-95%.

Preferably, in the step S5, the drying process is: and (3) drying the perilla fermentation leaves in the step (S4) through rough fire until the water content is 20-30%, and then drying through foot fire to enable the water content to be 4-6%.

Preferably, in the step S5, the temperature of the rough fire drying is 65-75 ℃, and the temperature of the foot fire drying is 60-70 ℃.

Further preferably, the treatment time of the rough fire drying is 80-100 min; the treatment time of the foot fire drying is 60-90 min.

Preferably, the drying treatment is: directly adopting a fragrance extracting machine to carry out primary drying treatment on the perilla fermented leaves in the step S4, wherein the treatment temperature is 70+/-5 ℃; after spreading to cool, the second drying treatment is carried out, and the treatment temperature is 60+/-5 ℃.

Further preferably, the time of the first drying treatment and the second drying treatment is 55 to 65 minutes.

Furthermore, the invention claims the perilla tea prepared by the processing method of the perilla tea.

The purple perilla tea has the appearance of a strip rope shape, is tightly tied and is dark brown; the tea soup Huang Gongshang is bright, aromatic, and mellow in taste.

Preferably, in the perilla tea, the content of the perillaldehyde is not less than 40% of the content of the volatile oil; the content of rosmarinic acid is not less than 1mg/g; the content of total flavone is not less than 1.5mg/g; the anthocyanin content is not less than 0.5mg/g.

Further preferably, in the perilla tea, the content of perillaldehyde is not less than 40% of the content of volatile oil; the content of rosmarinic acid is not less than 3mg/g; the content of total flavone is not less than 3mg/g; the anthocyanin content is not less than 2mg/g.

Further, the invention claims the application of the perilla tea in preparing antioxidant products.

Further, the invention also provides a purple perilla tea composition, which comprises the following components: the above Perillae herba tea and black tea.

Preferably, the purple perilla tea and the traditional black tea can be blended according to flavor evaluation and nutrition component consideration, the flavor quality of the traditional black tea can be improved after blending, the special flavor and nutrition of the purple perilla are endowed, and the health care effect of the traditional black tea is improved. More specifically, large leaf black tea such as Yunnan black tea, guangdong black tea, guangxi black tea, hainan black tea and the like can be selected for blending so as to show that the perilla tea composition has thick taste; middle and small leaf black tea, such as Fujian black tea, anhui black tea, jiangxi black tea, guizhou black tea, etc. can be selected for blending to show the mellow taste of the purple perilla tea composition.

Preferably, the perilla tea and the black tea can be mixed in different proportions. For example, the purple perilla tea and the black tea can be prepared according to the volume ratio of 1:1 to 1:9, blending, such as 1:1,1:2,1:3,1:4,1:5,1:6,1:7,1:8,1:9, the present invention is not limited thereto.

Preferably, the perilla tea and the black tea can be blended and processed in different modes. If the fresh perilla leaves and the fresh black tea leaves are withered together, kneading together; fermenting and oven drying; or respectively withering fresh leaves of Perilla frutescens and fresh leaves of black tea, respectively twisting, respectively fermenting, and co-baking; or the fresh perilla leaves and the fresh black tea leaves are manufactured separately in the withering process, or are manufactured separately in the withering process, the rolling process and the fermentation process, and then the fresh perilla leaves and the fresh black tea leaves are processed together; or respectively preparing finished products of Perilla tea and traditional black tea, and blending; or the perilla tea water and the black tea water are mixed to prepare the perilla tea water beverage and the like, and the invention is not limited to the perilla tea water beverage.

Compared with the prior art, the invention has the following beneficial effects:

(1) The invention takes the medicinal fresh leaves of the perilla as raw materials, has strong aroma of the perilla, is rich in rosmarinic acid and anthocyanin substances, and has the effects of releasing exterior and dispelling cold, reminding people to refresh the brain, reducing dryness and removing greasiness, and the like. In addition, the invention improves the micro-fermentation process, so as to maximally retain the effective components in the purple perilla and improve the flavor of the purple perilla. The perilla tea which is rich in antioxidant active ingredients and has strong fragrance and special flavor is finally formed by selecting specific perilla and combining a specific micro-fermentation process.

(2) Compared with common perilla tea, the perilla tea is rich in perillaldehyde, and substances such as caryophyllene, nerolidol, eucalyptol, longifolene, phytol and the like in volatile components are higher than those of common perilla tea. The contents of rosmarinic acid, caffeic acid, flavone and anthocyanin in the perilla tea are obviously increased. The micro-fermentation process promotes the conversion of substances in the perilla tea and enhances the health care function of the perilla tea. And the perilla tea has stronger antioxidation capability and has the same antioxidation activity as common black tea under high concentration as the perilla tea is selected and processed. According to the component evaluation result, the quality control standard of the perilla tea is defined as: the content of perillaldehyde is not less than 40% of volatile oil; the rosmarinic acid content is not less than 1mg/g; the total flavone content is not less than 1.5mg/g; the anthocyanin content is not less than 0.5mg/g.

(3) The perilla tea prepared by the invention and the traditional black tea are blended according to flavor evaluation and nutrition component consideration. The blended purple perilla tea composition can remarkably improve the flavor quality of the traditional black tea, endow purple perilla with special flavor and nutrition, and increase the health care effect of the traditional black tea.

Drawings

FIG. 1 is a photograph showing the processing course of perilla tea according to the present invention. Wherein, FIG. 1A shows the leaf morphology of the Perilla variety; FIG. 1B shows the rolled perilla leaves; FIG. 1C shows the morphology of the prepared perilla tea; fig. 1D shows a tea soup of perilla tea.

FIG. 2 shows the evaluation of the volatile oil components and content of the perilla tea.

FIG. 3 shows the results of measuring the contents of rosmarinic acid, caffeic acid, total flavonoids and anthocyanidins in perilla tea. Wherein, fig. 3A shows the content measurement result of rosmarinic acid in perilla tea; FIG. 3B shows the measurement result of the caffeic acid content in the perilla tea; FIG. 3C shows the measurement result of the total flavone content in the perilla tea; fig. 3D shows the measurement result of anthocyanin content in perilla tea.

FIG. 4 is an evaluation of DPPH radical scavenging rate of Perilla tea. Wherein, fig. 4A is a schematic diagram of DPPH radical scavenging rate of perilla tea and common perilla tea; fig. 4B is a schematic diagram of the biological DPPH radical scavenging rate of common black tea and perilla tea.

Detailed Description

The invention is further illustrated in the following drawings and specific examples, which are not intended to limit the invention in any way. Unless specifically stated otherwise, the reagents, methods and apparatus employed in the present invention are those conventional in the art.

Example 1 Perilla frutescens tea and processing method thereof

(1) Selecting purple perilla: picking fresh perilla leaves with tender stems and leaves as main materials in summer and autumn, and grading to remove foreign matters such as old leaves, roots and non-perilla leaves;

(2) Withering: the fresh perilla leaves are withered and spread at the temperature of 25 ℃,humidity of 70%, spreading leaf thickness of 1.5kg/m ² Controlling the water content of the fresh perilla leaves at 60% to obtain the perilla withered leaves, wherein the perilla withered She Shougan is soft and the stems are not easy to break;

(3) Twisting: twisting with a twisting machine, wherein during twisting, the temperature is controlled to be 30 ℃, the ambient humidity is controlled to be 70%, the twisting pressure is light-pressure twisting for 60min, and then re-compression twisting is carried out for 10min;

(4) Deblocking: deblocking the rolled perilla leaves for 2 hours;

(5) Fermentation: fermenting the deblocked perilla leaves in a fermentation frame of a fermentation chamber at a temperature of 30 ℃ and a humidity of 80% for 2.5 hours to obtain perilla fermentation leaves;

(6) And (3) drying: drying the fermented leaves of Perilla frutescens, and adopting a tea aroma extracting machine to carry out drying treatment, wherein the leaf spreading thickness is 3cm, the treatment temperature is 75 ℃, and the treatment time is 60min; and (3) after spreading and cooling, drying for a second time, wherein the treatment temperature is 65 ℃ and the treatment time is 60 minutes, and obtaining the perilla tea.

FIG. 1 is a photograph showing the processing course of perilla tea according to the present invention. Wherein, fig. 1A is a leaf morphology of perilla; FIG. 1B shows the rolled perilla leaves; FIG. 1C shows the morphology of the prepared perilla tea; fig. 1D shows a tea soup of perilla tea.

Example 2 Perilla frutescens tea and its processing method

(1) Selecting purple perilla: selecting fresh leaves of Perilla frutescens in summer and autumn, wherein the fresh leaves of Perilla frutescens are picked by hands mainly including tender stems and leaves, classifying the fresh leaves of Perilla frutescens, and removing foreign matters such as old leaves, roots and non-Perilla frutescens;

(2) Withering: withering and spreading fresh leaves of Perilla frutescens at 25deg.C with humidity of 70%, and thickness of leaf of 2kg/m ² Controlling the water content of the fresh perilla leaves to be 65%, so as to obtain the perilla withered leaves, wherein the perilla withered leaves She Shougan are soft and stems are not easy to break;

(3) Twisting: twisting with a twisting machine, wherein the temperature is 30deg.C, the ambient humidity is 70%, the twisting pressure is light pressure, medium pressure or heavy pressure, and the twisting time is 60min;

(4) Deblocking: deblocking the rolled perilla leaves for 2 hours;

(5) Fermentation: fermenting the deblocked perilla leaves in a fermentation frame of a fermentation chamber at 25 ℃ with the humidity of 80% for 3 hours to obtain the perilla fermentation leaves;

Example 3 Perilla tea and its processing method

(1) Selecting purple perilla: selecting fresh leaves of Perilla frutescens which are picked by hand and mainly comprise tender stems and leaves in summer and autumn, and grading the fresh leaves of Perilla frutescens to remove foreign matters such as old leaves, roots and non-Perilla frutescens;

(4) Deblocking: deblocking the rolled perilla leaves for 2 hours;

(6) And (3) drying: drying the fermented leaves of the perilla by adopting a turning plate type dryer to remove moisture rapidly, wherein the drying temperature is 70 ℃, the drying time is 90min, the fermented leaves of the perilla are dried until the moisture content is 25%, and then cooling to room temperature; and then drying the perilla leaves subjected to rough fire drying by adopting a fragrance extraction machine, wherein the temperature of the rough fire is 65 ℃ and the time is 60min, and drying the perilla fermentation leaves by the rough fire until the water content is 5%, so as to obtain the perilla tea.

Test case perilla tea component evaluation and quality control

(1) Detecting the content of volatile oil in the perilla tea by adopting a GC-MS method.

Extracting volatile oil: an organic solvent extraction method is adopted. The specific experimental steps are as follows: accurately weighing 0.2g of perilla tea prepared in example 1, grinding into powder by liquid nitrogen, adding 1.5mL of normal hexane, shaking uniformly up and down, performing ultrasonic treatment by an ultrasonic cleaner for 30min, taking out and shaking 3 times during the ultrasonic treatment, taking out and centrifuging at 12000rpm for 5min after ultrasonic treatment is finished, sucking the supernatant, adding a proper amount of anhydrous sodium sulfate, standing for 1h, centrifuging at 12000rpm for 5min, accurately sucking 1mL of the supernatant by a syringe, filtering the supernatant by a 0.22 mu m organic filter membrane in a sample bottle, placing the sample bottle in a vent, evaporating and concentrating, adding 500 mu L of normal hexane, and waiting for sample injection.

Preparation of control series standard solutions: precisely weighing perillaldehyde 10mg in a 10mL volumetric flask, dissolving with methanol to constant volume, and concentrating to 10 mg.mL ^-1 . Accurately sucking the solution 0, 0.5, 1, 2, 5, 10 and 20 mu L into a 1mL volumetric flask, and fixing the volume by methanol and shaking uniformly. The standard working solutions have concentrations of 0, 0.005, 0.01, 0.02, 0.05, 0.1, 0.2 mg.mL ^-1 . The following chromatographic conditions were used, and gas chromatography analysis and measurement were performed by automatically feeding samples at a feeding amount of 1. Mu.L.

And (3) detecting volatile oil components: GC-MS analysis was used. Chromatographic conditions: RXT-5MS quartz capillary column (30 m 0.25 μm); the pre-column pressure was 63.9 kPa; not split; the sample injection amount is 500 mu L; the temperature of the sample inlet is 260 ℃; the carrier gas is He; the initial temperature of the column is 80 ℃, the column is kept for 1min, and then the column is subjected to 15 ℃ for min ^-1 Is heated to 300 ℃ and is kept for 15min. One sample detection time was completed at 31min. Mass spectrometry conditions: the ionization mode is EI, and the filament current is 0.5mA; electron energy 70eV; multiplier voltage 0.86kV; the ion source is at 230 ℃, and the solvent is delayed for 1min; the mass-nuclear ratio m/z is 40-500. And (3) searching an NIST spectrum gallery according to Agilent qualitative software, and identifying the component types by combining artificial chemical structure analysis and judgment. Calculating the relative percentage of each chemical component of the volatile oil by a peak area normalization method. And calculating the absolute content of each chemical component according to the content of the perillaldehyde by adopting an external standard one-point method.

And comparing the perilla tea processed by the optimized micro-fermentation production process with the perilla dry leaf components. Fig. 2 shows the volatile oil components and content evaluation of the perilla tea, and the result is shown in fig. 2, wherein the content of the processed perilla aldehyde in the perilla tea is 43.53%. In addition, the volatile components also comprise beta-caryophyllene, nerolidol, eucalyptol, longifolene and phytol. The substances such as caryophyllene, caryophyllin, nerolidol, eucalyptol, longifolene and the like are obviously increased in the perilla tea compared with the dry leaves. The perillaldehyde is a medicinal perilla marking component specified in pharmacopoeia and mainly has the effects of relieving exterior syndrome, dispelling cold, promoting qi circulation and harmonizing stomach. The caryophyllene, nerolidol, eucalyptol, longifolene and other substances have good antioxidant and anti-inflammatory activities. Compared with common perilla tea, the common perilla tea mainly comprises the components of perillene and myristicin, and the components and the flavor of the common perilla tea are greatly different. A large amount of volatile oil components still remain in the processed perilla tea, which is the key for forming the flavor substances and the nutrition effects of the perilla tea.

(2) The HPLC method is adopted to measure the content of rosmarinic acid and caffeic acid in the perilla tea, and the specific steps include:

sample solution preparation: precisely weighing 0.3g of Perilla tea and common Perilla dry leaf powder prepared in example 1, respectively, adding 1.5mL of 80% methanol, respectively, ultrasonic extracting at 40deg.C for 40min, centrifuging supernatant at 12000rpm for 10min, and filtering.

Preparing a reference substance solution: the rosmarinic acid and the caffeic acid reference substances are taken to be properly weighed, and 80 percent of methanol is respectively added to prepare a rosmarinic acid reference substance solution with the concentration of 0.16mg per 1mL and a caffeic acid reference substance solution with the concentration of 0.26mg per 1 mL.

Content determination of rosmarinic acid and caffeic acid: according to high performance liquid chromatography (China pharmacopoeia 2015 edition four general rules 0512), respectively precisely sucking 10 μl of control solution and test solution, and injecting into liquid chromatograph. Chromatographic conditions: c18 column, methanol: a0.2% aqueous solution of phosphoric acid (25:75) was used as the mobile phase, the detection wavelength was 330nm, and the flow rate was 1mL/min. And (5) content measurement is carried out.

(3) And evaluating the anthocyanin and flavone contents in the perilla tea by adopting an ultraviolet spectrophotometry.

And (3) determining the content of anthocyanin: 0.2g of the perilla tea and the common perilla dry leaf powder prepared in example 1 are precisely weighed respectively, placed in conical flasks, 10mL of 0.1mol/L hydrochloric acid methanol solution is added respectively, extracted by ultrasound for 40min, cooled, taken out after the weight after loss is complemented by the 0.1mol/L hydrochloric acid methanol solution, centrifuged for 10min at 4000r/min, and the supernatant is sucked respectively and diluted by 10 times. A0.1 mol/L methanolic hydrochloric acid solution was used as a blank. The optical density values at wavelengths of 530, 620, 650nm were determined. The anthocyanin content was calculated according to the greeney formula as follows:

anthocyanin optical density value OD lambda= (OD ₅₃₀ -OD ₆₂₀ )-0.1(OD ₆₅₀ -OD ₆₂₀ )

Anthocyanin content (nmol/g) = [ (OD lambda/epsilon) × (V/m) ]x1000000)

Wherein: epsilon is anthocyanin molar extinction coefficient 4.62 multiplied by 10 ⁶ The method comprises the steps of carrying out a first treatment on the surface of the V is total volume of the extracting solution (mL); m is the sampling mass (g). Analysis was performed using a spectrophotometer.

Content determination of total flavonoids: 0.1g of perilla tea and 0.1g of common perilla dry leaf powder are respectively weighed precisely, placed in conical flasks with plugs, respectively added with 10mL of 70% ethanol, extracted by ultrasonic for 45min, cooled, weighed again, taken out after the weight loss is complemented by 70% ethanol, centrifuged for 10min at 4000r/min, respectively sucked up 1.0mL of supernatant, and developed (the development is the same as below). Standard curves for total flavonoids were used: taking about 8.5mg of rutin reference substance, precisely weighing, placing into a 25mL brown measuring flask, adding appropriate amount of 70% ethanol, placing into warm water, slightly shaking to dissolve, cooling, adding 70% ethanol to volume to scale, and shaking to obtain reference substance solution; precisely sucking 0.5mL, 1.0mL, 1.5mL, 2.0mL, 2.5mL and 3.0mL of the reference substance solution, respectively placing into 25mL measuring bottles, and adding 70% ethanol to compensate to 3.0mL; then adding 1mL of 5% sodium nitrite solution, shaking uniformly, and standing for 6min; adding 1mL of 10% aluminum nitrate solution, shaking uniformly, and standing for 6min; adding 10mL of sodium hydroxide test solution, finally using 70% ethanol to fix the volume to the scale, shaking uniformly, and standing for 15min. According to ultraviolet-visible spectrophotometry (Chinese pharmacopoeia 2015 edition four general rule 0401), absorbance is measured at 500nm wavelength, rutin mass is taken as abscissa, absorbance is taken as ordinate, and a standard curve is drawn. And measuring the absorbance of the test solution at the maximum absorption wavelength, and calculating the content of total flavonoids.

As shown in FIG. 3, the content of rosmarinic acid in the perilla tea was 3.11mg/g, and the content of caffeic acid was 0.198mg/g, and the content was significantly increased as compared with the common perilla tea. Rosmarinic acid and caffeic acid have antioxidant, antiinflammatory, and antitumor biological activities. Rosmarinic acid is also a natural antioxidant with a large dosage in current foods. The content of rosmarinic acid and caffeic acid in the processed Perilla tea is increased, so that the health care function of the Perilla tea is enhanced.

The content of total flavone and anthocyanin in the Perilla tea is 3.23mg/g and 2.33mg/g respectively, and is far higher than that in common Perilla tea. The total flavone and anthocyanin have pharmacological activities of resisting oxidation, resisting inflammation, resisting allergy and regulating blood sugar and blood fat, and are important compound substances in functional foods. The perilla rosmarinic acid, anthocyanin, flavone and other substances are water-soluble substances, and the total flavone and anthocyanin content in the perilla tea after fermentation treatment is high, so that the perilla rosmarinic acid, anthocyanin, flavone and other substances are main substances of the perilla functional components.

(4) Detecting DPPH free radical clearance rate and evaluating oxidation resistance of perilla tea

Sample solution preparation: respectively precisely weighing 1.5g of Perilla frutescens tea, common Perilla frutescens dry leaf powder and conventional black tea powder prepared in example 1, respectively adding 30mL of boiling water, performing ultrasonic extraction at 50deg.C for 40min, respectively collecting supernatant, centrifuging at 12000 and rpn for 10min, and filtering to obtain mother liquor of the extractive solution. Diluting the mother solution of the extracting solution with purified water according to a certain concentration to obtain test sample solutions with the concentration of 0.25, 0.5, 1, 2 and 4 mg/mL.

Adopts DPPH free radical scavenging ability kit (built by Nanjing). Respectively preparing a control tube, a measuring tube and a blank tube according to the specification of the kit, standing for 30min in a room in a dark place, zeroing by absolute ethyl alcohol, measuring absorbance at 517nm wavelength according to an ultraviolet-visible spectrophotometry (Chinese pharmacopoeia 2015 edition four general rules 0401), and calculating DPPH free radical clearance of each sample according to the formula:

DPPH radical clearance (%) = [ (1- (assay-a control)/(a blank) ×100%)

FIG. 4 is an evaluation of DPPH radical scavenging rate of Perilla tea. Wherein, fig. 4A is a schematic diagram of DPPH radical scavenging rate of perilla tea and common perilla tea; fig. 4B is a schematic diagram of the biological DPPH radical scavenging rate of common black tea and perilla tea. As shown in FIG. 4, under the concentration gradient of 250-4000ug/mL, the free radical clearance of the perilla tea and the common perilla tea of the invention shows good concentration dependence. Compared with common perilla tea under the same concentration, the DPPH free radical clearance rate of the perilla tea is higher than that of the common perilla tea, which indicates that the oxidation resistance of the perilla tea can be improved through micro-fermentation, and the perilla tea has better nutritive value. Compared with common black tea with the same concentration, the common black tea has insignificant concentration gradient of antioxidant activity. At a concentration of 250ug/mL, the common black tea is superior to the perilla tea of the invention. Whereas at high concentrations of 4000ug/mL, the common black tea was comparable to the antioxidant activity of the perilla tea of the present invention. The result shows that the perilla tea has higher antioxidation capability, and is tea drink with stronger antioxidation function.

The quality control index of the perilla tea is marked by the comprehensive evaluation of components and oxidation resistance that the perilla tea contains perillaldehyde, caryophyllene, nerolidol, eucalyptol and the like, and the content of the perillaldehyde is not lower than 40% of the content of volatile oil; the content of rosmarinic acid is not less than 1mg/g; the total flavone content is not less than 1.5mg/g; the anthocyanin content is not less than 0.5mg/g. The antioxidant capacity of the perilla tea can be increased through micro-fermentation, and compared with common perilla tea and common black tea, the perilla tea has equivalent antioxidant activity with common black tea under high concentration. The perilla tea has strong antioxidation capability, has unique flavor formed by volatile substances of perilla aldehyde, and is a functional tea rich in antioxidation active ingredients.

The foregoing examples are illustrative only and serve to explain some features of the method of the invention. The claims that follow are intended to claim the broadest possible scope as conceivable and the embodiments presented herein are demonstrated for the applicant's true test results. It is, therefore, not the intention of the applicant that the appended claims be limited by the choice of examples illustrating the features of the invention. Some numerical ranges used in the claims also include sub-ranges within which variations in these ranges should also be construed as being covered by the appended claims where possible.

Claims

1. The processing method of the perilla tea is characterized by comprising the following steps of:

s2, twisting: twisting the perilla withered leaves in the step S1;

s3, deblocking: deblocking the perilla leaves rolled in the step S2;

2. The process of claim 1, wherein in step S1, the moisture content of the perilla leaves is controlled to be 50-60%.

3. The process of claim 1 or 2, wherein in step S1, the spreading withering is spreading under natural conditions; or spreading and withering under the conditions that the temperature is 20-30 ℃ and the humidity is 60-80%.

4. The process of claim 1 or 2, wherein in step S2, the rolling process is controlled to a temperature of 22 to 30 ℃ and a humidity of 60 to 80%.

5. The method of claim 4, wherein in step S4, the fermentation treatment is fermentation under natural conditions; or the fermentation treatment is carried out under the conditions that the temperature is 22-30 ℃ and the humidity is 80-95%.

6. The method according to claim 5, wherein in step S5, the drying process is: and (3) drying the perilla fermentation leaves in the step (S4) through rough fire until the water content is 20-30%, and then drying through foot fire to enable the water content to be 4-6%.

7. The method for processing perilla tea according to claim 1, wherein the content of perillaldehyde in the perilla tea is not less than 40% of the content of volatile oil; the content of rosmarinic acid is not less than 1mg/g; the content of total flavone is not less than 1.5mg/g; the anthocyanin content is not less than 0.5mg/g.

8. The perilla tea prepared by the process of any one of claims 1 to 7.

9. Use of the perilla tea according to claim 8 for preparing an antioxidant product.

10. A perilla tea composition comprising: a perilla tea and black tea according to claim 8.