A method for increasing the content of β-ionone in seven-fingered peach leaves

Abstract

The present invention discloses a method for increasing the β-ionone content in the leaves of the seven-fingered peach, comprising saltwater soaking and a two-step heat incubation process. This method can effectively increase the β-ionone content of the seven-fingered peach leaves, enriching them with β-ionone, increasing their fragrant aroma, such as floral and woody, and enhancing the anti-cancer and anti-inflammatory effects of the resulting tea.

Description

Technical Field

[0001] The invention relates to the technical field of food fermentation, and in particular to a method for increasing the content of beta-ionone in leaves of Prunus mume. Background Art

[0002] β-ionone, a flavoring agent approved by the Flavor and Extract Manufacturers Association (FEMA) and the U.S. Food and Drug Administration, is commonly used in cosmetics, perfumes, and spices. It possesses rich aromas such as rose, woody, and violet. β-ionone has also been found to have antibacterial, anti-inflammatory, antioxidant, lipid-lowering, and cancer cell-inhibiting properties. However, the fresh leaves of the common genus Prunus ternatea (Seven-fingered Prunus ternatea) are not found to contain β-ionone, resulting in a lack of flavor and biological activity, limiting its application. Summary of the Invention

[0003] In order to solve the above problems, the present invention proposes a method for increasing the content of β-ionone in the leaves of Prunus mume.

[0004] The present invention provides a method for increasing the content of β-ionone in leaves of Prunus mume, comprising the following steps:

[0005] (1) Soak freshly picked Prunus mume leaves in light salt water and then place them in an oven to dry out the surface moisture;

[0006] (2) Heat-incubate the leaves at high temperature for 5-15 minutes, cool down and let them stand for 1-2 hours, heat-incubate them again for 5-15 minutes, and then cool down and let them stand for 2-4 hours;

[0007] (3) Bake the leaves after they have been left to rest until the moisture content reaches 4%-6%.

[0008] Optionally, in step (1), the seven-fingered ginseng may be either broad-leaved or thin-leaved; and the picked leaves are seven-fingered ginseng leaves that have grown for more than half a year. Preferably, the leaves are one to three years old.

[0009] Optionally, in step (1), the concentration of the light salt water is 1-5% (w / v), and the soaking time is 10 minutes to 20 minutes.

[0010] Optionally, in step (1), the drying temperature in the oven is 20°C-30°C.

[0011] Optionally, in step (1), after drying, an air shower step is further included to remove the fluff on the surface of the leaves.

[0012] Optionally, in step (1), the wind speed of the air shower is 0.25m / s-0.75m / s.

[0013] Optionally, in step (2), the high temperature heat incubation temperature range is 80°C-100°C, and the incubation needs to be continuously stirred to avoid uneven heating.

[0014] Optionally, in step (2), the cooling and standing temperature is controlled at 20°C-30°C.

[0015] Optionally, in step (3), the baking temperature ranges from 60°C to 80°C.

[0016] Unless otherwise specified, the equipment, reagents, processes, parameters, etc. involved in the present invention are conventional equipment, reagents, processes, parameters, etc. and are not given as examples.

[0017] All ranges recited herein include all points within the range.

[0018] Compared with the background technology, this technical solution has the following advantages:

[0019] 1. The present invention proposes a two-step thermal cultivation method, which effectively increases the β-ionone content in the leaves of seven-fingered peach.

[0020] 2. According to an embodiment of the present invention, a method for increasing the content of β-ionone in the leaves of seven-fingered peach is provided. The prepared seven-fingered peach leaves are rich in β-ionone, have a pleasant floral aroma, and have anti-cancer, anti-inflammatory, antioxidant and other effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 β-ionone standard curve.

[0022] Figure 2 Gas chromatography-mass spectrometry of Example 1 (the β-ionone peak is shown in the box).

[0023] Figure 3 Gas chromatography-mass spectrometry of Example 2 (the β-ionone peak is in the frame).

[0024] Figure 4 Gas chromatography-mass spectrometry of Example 3 (the β-ionone peak is shown in the box).

[0025] Figure 5 Gas chromatography-mass spectrometry of Comparative Example 1 (no β-ionone peak).

[0026] Figure 6 Gas chromatography-mass spectrometry of Comparative Example 2 (no β-ionone peak).

[0027] Figure 7 Gas chromatography-mass spectrum of Comparative Example 3 (no β-ionone peak).

[0028] Figure 8Gas chromatography-mass spectrometry of Comparative Example 4 (the β-ionone peak is in the frame).

[0029] Figure 9 Gas chromatography-mass spectrum of Comparative Example 5 (no β-ionone peak).

[0030] Figure 10 Gas chromatography-mass spectrometry of Comparative Example 6 (the β-ionone peak is less obvious). DETAILED DESCRIPTION

[0031] Detection method:

[0032] This method uses GC-MS for qualitative and quantitative analysis of β-ionone content. Determination was performed using a Shimadzu QP-2020 Plus gas chromatograph-mass spectrometer. The gas chromatograph was equipped with an HH-157330-U manual SPME injector, a 50 / 30μm DVB / CAR / PDMS extraction tip, and an Rtx-5MS capillary column (30 m × 0.25 mm × 0.25 μm). Headspace solid-phase microextraction (SPME) was performed before injection. The specific procedure was as follows: 2 g of sample was weighed, crushed, and placed into a 60 mL headspace vial. 29.99 mL of pure water and 1 μL of ethyl decanoate (86.3 μg / mL) were added. The sample was then equilibrated in an 80°C water bath for 10 minutes. After equilibration, the conditioned SPME tip was inserted into the headspace vial for adsorption for 30 minutes. After adsorption was complete, the tip was inserted into the GC injection port for desorption for 3 minutes before GC-MS analysis. The conditioning procedure for the SPME tip was as follows: a carrier gas flow rate of 3 mL / min, a temperature program, an inlet temperature of 250°C, an initial temperature of 75°C, a hold for 6 minutes, a temperature increase at 6°C / min to 120°C, a hold for 2 minutes, and a temperature increase at 20°C / min to 240°C, where it was held for 5 minutes. The desorption portion of the conditioning procedure lasted 3 minutes, for a total conditioning time of 25 minutes. GC-MS qualitative and quantitative analysis was performed as follows: high-purity helium was used as the carrier gas, with an injection volume of 1000 μL and a volume flow rate of 1.2 mL / min. The oven temperature was initially set at 40°C for 2 minutes, then increased to 140°C at a rate of 5°C / min. The temperature was then increased to 250°C at a rate of 10°C / min and held for 10 minutes. The mass spectrometer ion source was an EI source set at 250°C, and the interface temperature was set at 280°C. The mass spectra were scanned in the m / z range of 30 to 550 amu in positron ionization mode at 70 eV and an electron multiplier voltage of 1680 V. The mass spectra were indexed and compared with those of the National Institute of Standards and Technology (NIST). A standard mixture solution was prepared and analyzed using HS-SPME in SIM mode to establish a calibration curve and calculate the content.

[0033] Example 1: Freshly picked schizonepeta serrata leaves were washed, soaked in 1% (w / v) light salt water for 10 minutes, placed in a 20°C oven to dry out surface moisture, and then air-showered at a wind speed of 0.25 m / s to remove surface hair. The leaves were then incubated at 80°C for 5 minutes with rotation, cooled, and then kept at a constant temperature of 20°C for 1 hour. After resting, the leaves were incubated again at 80°C for 5 minutes with rotation, cooled again, and kept at a constant temperature of 20°C for 2 hours. Finally, the leaves were baked at 60°C until the moisture content dropped to 5%. The dry weight of the schizonepeta serrata leaves prepared in this example showed a β-ionone content of 7.38 mg / g, significantly higher than that in Comparative Example 3. β-ionone was not found in Comparative Examples 1, 2, 4, and 5 (Table 1).

[0034] Example 2: Freshly picked ginseng leaves were washed, soaked in 3% (w / v) light salt water for 15 minutes, placed in a 25°C oven to dry out surface moisture, and then air-showered at a wind speed of 0.5 m / s to remove surface hair. The leaves were then incubated with rotation at 90°C for 10 minutes, cooled, and then kept at a constant temperature of 25°C for 1.5 hours. After resting, the leaves were incubated again at 90°C with rotation for 10 minutes, cooled again, and kept at a constant temperature of 25°C for 3 hours. Finally, the leaves were baked at 70°C until the moisture content dropped to 5%. Compositional analysis showed that the β-ionone content of the ginseng leaves prepared in this example was 5.48 mg / g dry weight, significantly higher than that in Comparative Example 3. β-ionone was not found in Comparative Examples 1, 2, 4, or 5 (Table 1).

[0035] Example 3: Freshly picked seven-fingered peach leaves were washed, soaked in 5% (w / v) light salt water for 20 minutes, placed in a 30°C oven to dry out surface moisture, and air-showered at a wind speed of 0.75 m / s to remove surface hair. The leaves were incubated with rotation at 100°C for 15 minutes, cooled, and then kept at a constant temperature of 30°C for 2 hours. After being kept at a constant temperature, the leaves were incubated again at 100°C for 15 minutes with rotation, cooled again, and kept at a constant temperature of 30°C for 4 hours. Finally, the leaves were baked at 80°C until the moisture content dropped to 5%. Compositional analysis showed that the dry weight of the seven-fingered peach leaves prepared in this example contained 6.05 mg / g of β-ionone, significantly higher than that in Comparative Example 3. β-ionone was not found in Comparative Examples 1, 2, 4, or 5 (Table 1).

[0036] Comparative Example 1: Freshly picked Prunus mume leaves were washed and not treated in any way. Aroma analysis showed that no ionones were found in this comparative example (Table 1).

[0037] Comparative Example 2: Freshly picked Prunus mume leaves were washed (same as in Example 1) and air-dried in a naturally ventilated environment for 6 hours. The composition results showed that no ionones were found in this comparative example (Table 1).

[0038] Comparative Example 3: The salt water soaking and washing step in Example 2 was omitted, and the other methods were the same. The composition results showed that the content of β-ionone in the dry weight of the seven-fingered peach leaves prepared in this comparative example was 4.02 mg / g (Table 1).

[0039] Comparative Example 4: The heat incubation and high-temperature baking steps in Example 2 were omitted (i.e., the brine rinsing and air drying steps were retained). The other methods were the same. The compositional analysis showed that no ionone was found in this comparative example (Table 1).

[0040] Comparative Example 5: The heat incubation step was removed from Example 2, and the other methods were the same. The composition results showed that no ionone was found in this comparative example (Table 1).

[0041] Comparative Example 6: Only one heat incubation step was retained in Example 2, and the other methods were the same. The composition results showed that the content of β-ionone in the dry weight of the seven-fingered peach leaves prepared in this comparative example was 2.30 mg / g (Table 1).

[0042] Table 1 Quantitative results of aroma components

[0043] β-ionone content (mg / g) Example 1 7.38±3.55a Example 2 5.48±0.22a Example 3 6.05±0.18a Comparative Example 1 Comparative Example 2 Comparative Example 3 4.02±0.06b Comparative Example 4 Comparative Example 5 Comparative Example 6 2.30±1.02c

[0044] Note: The information in the table is grouped using Fisher LSD method and 95% confidence level. Different letters indicate significant differences.

[0045] In summary, according to the embodiments of the present invention, the two-step thermal incubation method can effectively increase the β-ionone content, have a distinct and pleasant floral aroma, and enhance its anti-cancer and anti-inflammatory effects.

Claims

1. A method for increasing the content of β-ionone in leaves of Prunus mume, characterized in that: The following steps are involved: (1) Soaking freshly picked seven-fingered peach leaves in light salt water, and then placing them in an oven to dry the surface moisture; the light salt water concentration is 1-5% (w / v), the soaking time is 10 minutes to 20 minutes; the drying temperature in the oven ranges from 20°C to 30°C; (2) The leaves are first heat-incubated at high temperature for 5 minutes to 15 minutes, cooled and allowed to stand for 1 hour to 2 hours, then heat-incubated again for 5 minutes to 15 minutes, and then cooled and allowed to stand for 2 hours to 4 hours; the temperatures for the first heat-incubation and the second heat-incubation are 80°C to 100°C respectively; the cooling and standing temperature is controlled at 20°C to 30°C; (3) Bake the leaves after standing to a moisture content of 4%-6%; the baking temperature range is 60°C-80°C.

2. The method according to claim 1, wherein In step (1), the picked seven-fingered peach leaves are seven-fingered peach leaves that have grown for more than half a year.

3. The method according to claim 1, wherein In step (1), after drying, an air shower step is also included.

4. The method according to claim 3, wherein The wind speed of the air shower is 0.25m / s-0.75m / s.

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