Processing method of lemon myrtle leaves and application thereof
By using pure water extraction and compound probiotic fermentation processes, the problem of insufficient extraction of polyphenols from lemon myrtle leaves was solved, resulting in a significant increase in polyphenol content and antioxidant activity, and the production of lemon myrtle leaf fermentation liquid that can be used in a variety of foods.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- TIANJIN JICUI BIOTECHNOLOGY CO LTD
- Filing Date
- 2026-02-28
- Publication Date
- 2026-06-12
AI Technical Summary
In existing technologies, steeping lemon and peach leaves in hot water cannot extract enough polyphenols, thus hindering the further utilization of their beneficial components.
A fermentation process combining pure water extraction with a compound probiotic fermentation process of Lactobacillus plantarum, Acetobacter pasteurellium, and Kluyveromyces martensii was adopted, and the extraction temperature and fermentation conditions were optimized to prepare lemon myrtle leaf fermentation broth.
It significantly improved polyphenol content and antioxidant activity, with the total polyphenol content of the fermentation broth reaching 868.57 μg/mL and the DPPH free radical scavenging rate reaching 75.3%. It can be applied to various food forms and has excellent sensory quality.
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Abstract
Description
Technical Field
[0001] This invention provides a method for deep processing lemon-scented peach leaves and its application, relating to the field of food raw material processing technology. Background Technology
[0002] Lemon peach leaves ( Backhousia citriodora F. Muell is the leaf of the lemon myrtle (F. Muell), a plant belonging to the genus F. Muell in the family Myrtaceae. This plant is native to Queensland, Australia, and the entire plant can be used, but the lemon myrtle leaf is the most widely used.
[0003] Existing research on the deep processing of lemon myrtle leaves mainly focuses on the extraction of volatile oils, with an emphasis on using the leaves' aroma to enhance the flavor of food. The application of lemon myrtle leaves is primarily concentrated in the daily chemical industry, emphasizing their antibacterial properties. In the food sector, patent CN216271010U discloses a novel lemon myrtle tea bag. The raw materials undergo harvesting, washing, screening, and drying, but no further deep processing is performed, and hot water brewing cannot fully extract the polyphenols from the lemon myrtle leaves. Some have proposed fermenting Cistanche deserticola with lemon myrtle leaves to obtain a mixed freeze-dried powder. This freeze-dried powder is said to have aphrodisiac and kidney-tonifying functions and improve spermatorrhea, but its applicable population is limited. Summary of the Invention
[0004] This invention provides a deep processing method for lemon myrtle leaves and its application, which solves the problem in the prior art that hot water brewing of lemon myrtle leaves cannot extract enough polyphenols and cannot further utilize the effective components of lemon myrtle leaves.
[0005] This invention is implemented by including the following steps: (1) Extraction treatment: The lemon myrtle leaf powder that has been picked, washed, selected, dried and crushed to pass through an 80-mesh sieve is mixed with pure water at a material-to-liquid ratio of 1:(40-75) and extracted at a constant temperature of 45-80℃ for 30-50 min to obtain lemon myrtle leaf extract. (2) Probiotic fermentation treatment: Add 3-8% carbon source by mass of the lemon myrtle leaf extract to the extract and transfer it to a fermentation tank. Inoculate with Lactobacillus plantarum, Acetobacter pasteurellum and Kluyveromyces martensii in a mass ratio of 1:1:1. The total inoculum is 1-3%. Fermentation is carried out at 30-37℃, natural pH and tank pressure of 0.05-0.05MPa. When the pH of the fermentation liquid drops below 3.8, the fermentation is stopped. Sterilize by maintaining the temperature at 85℃ for 50 min and cooling to room temperature to obtain lemon myrtle leaf fermentation liquid.
[0006] In a preferred embodiment, in step (1), the extraction temperature is 60-70°C, preferably 65°C.
[0007] In a preferred embodiment, in step (1), the ratio of lemon peach leaf powder to pure water is 1:(50-65), preferably 1:50.
[0008] In a preferred embodiment, in step (1), the carbon source and the lemon myrtle leaf extract... The material-to-liquid ratio is (5-6):100.
[0009] In a preferred embodiment, the carbon source is one or more of brown sugar, sucrose, and glucose. Sucrose is preferred.
[0010] In a preferred embodiment, the fermentation time in step (2) is 7 to 10 days, preferably 9 days.
[0011] The fermentation broth of lemon myrtle leaves provided by this invention has a total polyphenol content ≥800 μg / mL, a DPPH free radical scavenging rate ≥70%, a pH of 3.5-3.8, a total acidity of 5-8 g / L, and a viable count ≥1×10⁻⁶. 6 CFU / mL (before sterilization).
[0012] This invention also provides an application of a deep processing method for lemon myrtle leaves, wherein the lemon myrtle leaf fermentation liquid is used to prepare one or more of the following: fermented beverages, solid beverages, compressed candies, nutrition bars, jellies, and gummies. The application method of the lemon myrtle leaf fermentation liquid in the food industry can refer to the usage methods of other plant fermentation liquids applicable to the food industry.
[0013] The beneficial effects of this invention are: 1. Green and environmentally friendly process: This invention uses pure water extraction and does not use organic solvents throughout the process. Compared with traditional organic solvent extraction methods, the process is simpler, more energy-efficient, and more environmentally friendly, meets food safety requirements, and reduces costs by about 30%.
[0014] 2. Significantly increased content of active ingredients: Through optimized extraction temperature (65℃) and compound probiotic fermentation process, the total polyphenol content in lemon myrtle leaf fermentation liquid reached 868.57 μg / mL, which is 2.24 times that of the total polyphenol content when brewed with boiling water (387.12 μg / mL).
[0015] 3. Significant Synergistic Fermentation Effect: This invention creatively employs a compound fermentation system composed of *Lactobacillus plantarum*, *Acetobacter pasteurellium*, and *Kluyveromyces martensii* in a 1:1:1 ratio. The three bacteria produce a synergistic effect: the lactic acid produced by *Lactobacillus plantarum* lowers the pH value, creating a suitable environment for acetic acid bacteria and yeast; the acetic acid produced by *Acetobacter pasteurellium* further enhances acidity and effervescence; and the metabolites of *Kluyveromyces martensii* enrich the flavor profile and promote the biotransformation of polyphenols. Experimental results show that the polyphenol content fermented with the compound bacteria is 58% higher than that fermented with single lactic acid bacteria, 67% higher than that fermented with single acetic acid bacteria, and 72% higher than that fermented with single yeast.
[0016] 4. Excellent antioxidant activity: The DPPH free radical scavenging rate of the fermentation broth reached 75.3%, the antioxidant capacity of ABTS reached 168.5 μmol Trolox / L, and the total antioxidant capacity T-AOC reached 0.58 U / mL. The DPPH scavenging rate of the fermentation broth of this invention is significantly higher than that of the unfermented extract (42.1%), indicating that it has good antioxidant function.
[0017] 5. Excellent sensory quality: The fermented liquid retains the natural lemon aroma of lemon-scented peach leaves, while also possessing the acidity, mellow taste, and microbubbly sensation brought about by fermentation. It has a rich flavor profile and can be used directly as a functional beverage or, after drying, for use in solid foods.
[0018] 6. Wide range of applications: The lemon-scented peach leaf fermentation liquid obtained by this invention can be used as a liquid raw material for beverages, jellies and other products, or it can be spray-dried or freeze-dried into powder for use in various food forms such as solid beverages, compressed candies, and nutrition bars, making it flexible in application. Detailed Implementation
[0019] The present invention will now be described in detail with reference to specific embodiments. Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods; unless otherwise specified, the materials and reagents used are commercially available.
[0020] The lemon myrtle leaf raw material used in the example is dried lemon myrtle leaves imported from Australia (supplier: Australian Native Products; specification: Dried Leaf, Medium Cut), which are further crushed to pass through an 80-mesh sieve before use.
[0021] The strain used in the examples: Lactobacillus plantarum ( Lactiplantibacillus plantarum CICC22204), Acetobacter pasteurellosis ( Acetobacter pasteurianus CICC 21811), Kluyveromycin ( Kluyveromyces marxianusCICC1636). For activation, *Lactobacillus plantarum* was inoculated into MRS liquid medium and activated at 37°C and 100 rpm for 18 h, with a final concentration ≥3.0 × 10⁻⁶. 8 CFU / mL; *Acetobacter pasteurellium* was inoculated into acetic acid bacteria medium and activated at 37℃ and 120 rpm for 20 h, with a final concentration ≥3×10⁻⁶. 8 CFU / mL; Kluyveromyces martensii was inoculated into YPD liquid medium and activated at 30℃ and 150 rpm for 24 h, with a final concentration ≥2×10⁻⁶. 8 CFU / mL. Example
[0022] Effects of different material-to-liquid ratios on the flavor and state of lemon myrtle leaf extract 2.0 g of lemon myrtle leaves were weighed and extracted with pure water at a ratio of 1:40, 1:50, 1:60, and 1:75 respectively at 50℃ for 50 min. The flavor and state of each group of extracts were evaluated. The extracts were scored from three dimensions: taste (whether the taste of the extract is mellow and whether there is bitterness), aroma, and color. Each item had a full score of 5 points. The evaluation results of the four groups are shown in Table 1.
[0023] Table 1. Flavor and State Scores of Lemon Myrtle Leaf Extracts with Different Solid-Liquid Ratios
[0024] As shown in Table 1, the lemon myrtle leaf extract with a material-to-liquid ratio of 1:50 has a mild taste, almost no bitterness, a distinct lemon aroma, and a clear, light yellow-brown color. All three indicators are the best among the four groups, so a material-to-liquid ratio of 1:50 is selected for subsequent processing.
[0025] Example 2 Effect of different extraction temperatures on the total polyphenol content in lemon and peach extract Five portions of 2.0 g lemon myrtle leaves were weighed and processed as follows: Treatment 1: 2.0 g lemon myrtle leaves + 100 mL pure water, at room temperature 25℃, for 50 min; Treatment 2: 2.0 g lemon myrtle leaves + 100 mL pure water, 45℃ water bath, 50 min; Treatment 3: 2.0 g lemon myrtle leaves + 100 mL pure water, 65℃ water bath, 50 min; Treatment 4: 2.0 g lemon myrtle leaves + 100 mL pure water, 85℃ water bath, 50 min; Treatment 5 (control): 2.0 g lemon myrtle leaves + 100 mL boiling water, steep for 3 min.
[0026] After completing each treatment group, the extracts were cooled to room temperature, filtered, and samples were taken to determine the total polyphenol content in each extract group. The determination of total polyphenol content was performed in accordance with GB / T 31740.2-2015 "Tea Products - Part 2: Determination of Tea Polyphenols". The Folin-Ciocalteu colorimetric method in the national standard was used, and a standard curve was plotted using gallic acid (GAE) as the standard. The results are expressed as GAE equivalents (unit: μg / mL). The experimental results are shown in Table 2.
[0027] Table 2. Total polyphenol content in lemon and peach extracts at different extraction temperatures.
[0028] As shown in Table 2, under the condition that the extraction time is 50 min, the higher the extraction temperature, the higher the total polyphenol content in the extract. The polyphenol content extracted at 65℃ is 2.24 times that extracted by boiling water. Although the polyphenol content extracted at 85℃ is slightly higher than that extracted at 65℃, considering energy consumption and the needs of subsequent fermentation, 65℃ is selected as the preferred extraction temperature.
[0029] Example 3 Comparison of single-strain fermentation of lemon and peach extracts at different extraction temperatures To verify the advantages of mixed-strain fermentation, single-strain fermentation experiments were first conducted. Three strains of *Lactobacillus plantarum*, *Acetobacter pasteurellium*, and *Kluyveromyces martensii* were taken from a -80℃ freezer and purified three times by streaking on their respective suitable culture media to obtain single colonies. These single colonies were then inoculated into their respective liquid activation media. Lactobacillus plantarum: MRS liquid medium, 37℃, 150 rpm, anaerobic culture for 20 h; Acetobacter pasteurellum: Acetic acid bacteria liquid culture medium, 37℃, 150 rpm, aerobic culture for 20 h; Kluyveromyces martensii: YPD liquid medium, 30℃, 150 rpm, aerobic culture for 20 h.
[0030] The lemon myrtle leaf extract obtained from Example 2 at 65℃ was dispensed into smaller portions and inoculated with a single strain (2% inoculum). 5% sucrose was added, and the extracts were allowed to ferment at suitable temperatures for each strain for 9 days. A control group without inoculation was also included.
[0031] After fermentation, the total polyphenol content and DPPH free radical scavenging rate of each group were measured. The total polyphenol content was used as a reference. The DPPH free radical scavenging rate was determined as follows: 2 mL of 0.1 mmol / L DPPH solution was added to the sample solution, and the reaction was carried out in the dark using the Folin-Ciocalteu colorimetric method for 20 min. The absorbance A1 was measured at 517 nm. 2 mL of anhydrous ethanol was used as a control group instead of the DPPH solution, and the absorbance A2 was measured. 2 mL of anhydrous ethanol was used as a blank group instead of the sample solution, and the absorbance A0 was measured. The DPPH free radical scavenging rate was calculated according to the following formula I:
[0032] The results are shown in Table 3.
[0033] Table 3. Results of single-strain fermentation of lemon-peach extract at different extraction temperatures.
[0034] As shown in Table 3, single-strain fermentation can increase polyphenol content and antioxidant activity, but the increase is limited. Lactobacillus plantarum fermentation showed the best effect, increasing polyphenol content by 20.5% compared to unfermented fermentation, but still not reaching the ideal level. This provides a basis for comparison in complex-strain fermentation.
[0035] Example 4 Optimization of the fermentation process of lemon and peach extract using compound bacteria and screening of carbon sources Based on the results of Examples 2 and 3, a compound microbial fermentation was carried out using lemon myrtle leaf extract extracted at 65°C.
[0036] 4.1 Optimization of strain ratio Seed cultures of the three strains were prepared according to the method in Example 3. Lemon myrtle leaf extract extracted at 65°C was dispensed into smaller portions, 5% sucrose was added, and the three strains were inoculated at different ratios (total inoculum amount 3% for each strain). The cultures were then allowed to ferment at 35°C for 9 days. The experimental design is shown in Table 4.
[0037] Table 4 Optimization of Microbial Strains
[0038] As shown in Table 4, group B (three strains in a 1:1:1 ratio) exhibited the best fermentation effect, with a polyphenol content of 1285.42 μg / mL, which is 1.94 times that of the unfermented extract and 1.61 times that of fermentation with a single Lactobacillus plantarum. Therefore, the optimal strain ratio was determined to be 1:1:1.
[0039] 4.2 Screening of the optimal carbon source Lemon myrtle leaf extract (material-to-liquid ratio 1:50) was extracted at 65℃. Sucrose, brown sugar and glucose were added at 5% each, and the three bacteria were inoculated at a ratio of 1:1:1 (total inoculum 2%). The mixture was allowed to ferment statically at 35℃ and natural pH. After 7 days, the total polyphenol content of the fermentation broth was determined by the Folin-Ciocalteu colorimetric method. The results are recorded in Table 5.
[0040] Table 5. Total polyphenol content of lemon-peach fermentation broth with different carbon sources
[0041] As shown in Table 5, sucrose was selected as the carbon source, resulting in the highest total polyphenol content in the fermentation broth. Therefore, sucrose was chosen as the carbon source for the complex microbial fermentation.
[0042] 4.3 Fermentation of compound bacteria under optimal conditions Lemon myrtle leaf extract (65℃, material-to-liquid ratio 1:50) was used, with 5% sucrose added. Three types of bacteria (total inoculum 2%) were inoculated at a 1:1:1 ratio and allowed to ferment statically at 35℃, natural pH, and 0.05 MPa pressure. Changes in pH, total acidity, polyphenol content, and antioxidant activity were monitored during fermentation.
[0043] After 9 days of fermentation, the pH dropped to 3.7 and the total acidity reached 6.2 g / L. At this point, the fermentation was stopped, and the mixture was sterilized by maintaining the temperature at 85℃ for 50 minutes and then cooled to room temperature to obtain lemon myrtle leaf fermentation broth.
[0044] Example 5 Efficacy verification and finished product preparation of lemon-peach fermentation broth 5.1 Quality Indicators Testing of Fermentation Broth Lemon-scented peach leaf fermentation broth was prepared according to the optimized process in Example 4, and comprehensive quality and efficacy indicators were tested.
[0045] Table 6. Fermentation Broth Quality Index Test Table
[0046] As shown in Table 6, all indicators of the fermentation broth met the expected targets, demonstrating excellent antioxidant activity and good sensory quality.
[0047] 5.2 Preparation of Lemon-Peach Leaf Fermented Flavored Beverage Formula and its weight percentages: 90% lemon myrtle leaf fermentation liquid, 5% honey, 3% fructose syrup, 0.1% citric acid, 0.05% xanthan gum, and pure water to make up to 100%.
[0048] Process: Mix the raw materials in proportion, homogenize (15 MPa, twice), fill, sterilize at 121℃ for 15 min, cool, and obtain lemon peach fermented beverage.
[0049] Product features: It has a refreshing lemon aroma and a mellow fermented taste, with a balanced sweet and sour flavor and a slightly bubbly texture. The total polyphenol content is ≥1500 μg / mL, the DPPH removal rate is ≥70%, and the shelf life is ≥6 months at room temperature.
[0050] 5.3 Sensory Evaluation Twenty professional tasters were organized to conduct a sensory evaluation of the lemon-peach fermented beverage (out of 10 points). Each item was scored according to four dimensions: color (3 points), taste (3 points), aroma (2 points), and clarity (2 points), with a maximum score of 10 points. The average score of the 20 evaluators (rounded to one decimal place) was taken as the sensory evaluation result, and the following average score was obtained.
[0051] Aroma: 8.7 (prominent lemon scent with fermented notes); Taste: 8.5 (balanced sweet and sour, rich and full-bodied, with moderate effervescence); Color: 8.3 (light yellow, clear and transparent). Overall Acceptability: 8.6.
[0052] Example 6 Preparation of Lemon-Peach Baking Powder and Its Application in Solid Foods 6.1 Preparation of Lemon-Peach Baking Powder The lemon myrtle leaf fermentation broth prepared in Example 4 was mixed with 10% maltodextrin as a carrier and then subjected to low-temperature vacuum drying at a temperature not exceeding 60°C. After drying, the mixture was pulverized. A light yellow powder was obtained with a moisture content ≤5%, a total polyphenol content (on a dry basis) ≥15 mg / g, and a DPPH scavenging rate (1 mg / mL, aqueous solution) ≥65%.
[0053] 6.2 Application of Lemon and Peach Baking Powder in Solid Beverages Formula: 20% lemon peach baking powder, 15% inulin, 20% xylitol, 1% citric acid, 0.5% flavoring, and maltodextrin to make up to 100%.
[0054] Process: Mix all raw materials thoroughly, pass through a 60-mesh sieve, and package to obtain lemon peach fermented solid beverage.
[0055] Preparation method: Take 5g of solid beverage and add 200mL of warm water (40-50℃) to prepare it for drinking.
[0056] Product features: Rich lemon aroma, sweet and sour taste, each cup of beverage provides ≥150 mg of total polyphenols, with good antioxidant function.
[0057] 6.3 Application of Lemon-Peach Baking Powder in Compressed Candy Formula: 30% lemon peach baking powder, 40% xylitol, 20% mannitol, 8% microcrystalline cellulose, 1.5% magnesium stearate, and 0.5% flavoring.
[0058] Process: Mix all raw materials evenly, compress into tablets using a rotary tablet press (0.5 g tablet weight, 12 mm diameter, hardness ≥50 N), and package to obtain lemon peach fermented compressed candy tablets.
[0059] Product features: Each candy provides ≥22.5 mg of total polyphenols, suitable for daily supplementation of antioxidants, and is easy to carry.
[0060] Example 7 Stability test The lemon-peach fermented beverage prepared in Example 5 and the baking powder prepared in Example 6 were stored under the following conditions, and the changes in total polyphenol content and DPPH scavenging rate were periodically monitored: Fermented beverage: room temperature (25°C), protected from light; Baking powder: room temperature (25°C), sealed, protected from light. The results showed that the fermented beverage retained ≥90% of total polyphenols and ≥88% of DPPH scavenging rate within 6 months, exhibiting good sensory quality; the baking powder retained ≥92% of total polyphenols and ≥90% of DPPH scavenging rate within 12 months, without clumping or discoloration.
[0061] The above results indicate that the product prepared by this invention has good stability and is suitable for industrial production and commercial application.
[0062] Comparative Example 1 To further illustrate the advantages of this invention, the following comparative experiments were conducted using different fermentation methods: Comparative Example 1-1: No fermentation, extraction only at 65℃; Comparative Example 1-2: Single Lactobacillus plantarum fermentation (inoculum 2%); Comparative Example 1-3: Dual-strain fermentation (Lactobacillus plantarum + Kluyveromyces martensii, 1% each); Example 3: Triple-strain compound fermentation (Lactobacillus plantarum + Acetobacter pasteurellium + Kluyveromyces martensii, 1% each). The comparison results are shown in Table 7.
[0063] Table 7 Comparison of Example 3 and Comparative Example
[0064] As shown in Table 7, the three-strain compound fermentation scheme of the present invention is significantly superior to non-fermentation, single-strain fermentation and dual-strain fermentation in terms of polyphenol content, antioxidant activity and sensory quality, demonstrating the synergistic effect of the three strains.
[0065] Comparative Example 2 Comparison with commercially available products The lemon-peach fermented beverage prepared according to the present invention was compared with commercially available lemon tea beverages and lemon-peach leaf tea bags (brewed according to instructions). The results are shown in Table 8.
[0066] Table 8 Comparison Experiment with Commercially Available Products
[0067] As shown in Table 8, the polyphenol content and antioxidant activity of the product of this invention far exceed those of similar products sold in the market, giving it a significant competitive advantage and health value.
[0068] The beneficial effects of this invention are: 1. Green and environmentally friendly process: This invention uses pure water extraction and does not use organic solvents throughout the process. Compared with traditional organic solvent extraction methods, the process is simpler, more energy-efficient, and more environmentally friendly, meets food safety requirements, and reduces costs by about 30%.
[0069] 2. Significantly increased content of active ingredients: Through optimized extraction temperature (65℃) and compound probiotic fermentation process, the total polyphenol content in lemon myrtle leaf fermentation liquid reached 868.57 μg / mL, which is 2.24 times that of the total polyphenol content when brewed with boiling water (387.12 μg / mL).
[0070] 3. Significant Synergistic Fermentation Effect: This invention creatively employs a compound fermentation system composed of *Lactobacillus plantarum*, *Acetobacter pasteurellium*, and *Kluyveromyces martensii* in a 1:1:1 ratio. The three bacteria produce a synergistic effect: the lactic acid produced by *Lactobacillus plantarum* lowers the pH value, creating a suitable environment for acetic acid bacteria and yeast; the acetic acid produced by *Acetobacter pasteurellium* further enhances acidity and mouthfeel; and the metabolites of *Kluyveromyces martensii* enrich the flavor profile and promote the biotransformation of polyphenols. Experimental results show that the polyphenol content fermented with the compound bacteria is 58% higher than that fermented with single lactic acid bacteria, 67% higher than that fermented with single acetic acid bacteria, and 72% higher than that fermented with single yeast.
[0071] 4. Excellent antioxidant activity: The DPPH free radical scavenging rate of the fermentation broth reached 75.3%, the antioxidant capacity of ABTS reached 168.5 μmol Trolox / L, and the total antioxidant capacity T-AOC reached 0.58 U / mL. The DPPH scavenging rate of the fermentation broth of this invention is significantly higher than that of the unfermented extract (42.1%), indicating that it has good antioxidant function.
[0072] 5. Excellent sensory quality: The fermented liquid retains the natural lemon aroma of lemon peach leaves, while also possessing the acidity, mellow taste and refreshing sensation brought about by fermentation. It has a rich flavor profile and can be used directly as a functional beverage or, after drying, as a solid food product.
[0073] 6. Wide range of applications: The lemon-scented peach leaf fermentation liquid obtained by this invention can be used as a liquid raw material for beverages, jellies and other products, or it can be spray-dried or freeze-dried into powder for use in various food forms such as solid beverages, compressed candies, and nutrition bars, making it flexible in application.
Claims
1. A method for deep processing lemon-scented peach leaves, characterized in that, Includes the following steps: (1) Extraction treatment: The lemon myrtle leaf powder that has been picked, washed, selected, dried and crushed to pass through an 80-mesh sieve is mixed with pure water at a material-to-liquid ratio of 1:(40-75) and extracted at a constant temperature of 45-80℃ for 30-50 min to obtain lemon myrtle leaf extract. (2) Probiotic fermentation treatment: Add 3-8% carbon source by mass of the lemon myrtle leaf extract to the extract and transfer it to a fermentation tank. Inoculate with Lactobacillus plantarum, Acetobacter pasteurellum and Maxacryl yeast in a mass ratio of 1:1:
1. The total inoculation amount is 1-3%. Fermentation is carried out at 30-37℃, natural pH and tank pressure of 0.05-0.05MPa. When the pH of the fermentation liquid drops below 3.8, the fermentation is stopped. Sterilize by maintaining at 85℃ for 50 min and cooling to room temperature to obtain lemon myrtle leaf fermentation liquid.
2. The method for deep processing lemon-scented peach leaves according to claim 1, characterized in that, In step (1), the extraction temperature is 60-70℃.
3. The method for deep processing lemon-scented peach leaves according to claim 1, characterized in that, In step (1), the ratio of lemon peach leaf powder to pure water is 1:(50-65).
4. The method for deep processing lemon-scented peach leaves according to claim 1, characterized in that, In step (1), the ratio of the carbon source to the lemon myrtle leaf extract is (5-6):
100.
5. A method for deep processing lemon-scented peach leaves according to claim 4, characterized in that, The carbon source is one or more of brown sugar, sucrose, and glucose.
6. The method for deep processing lemon-scented peach leaves according to claim 1, characterized in that, In step (2), the fermentation time is 7 to 10 days.
7. The application of the deep processing method for lemon-scented peach leaves as described in claim 1, characterized in that, Lemon myrtle leaf fermentation liquid is used to prepare one or more of the following: fermented beverages, solid beverages, compressed candies, nutrition bars, jellies, and gummies.