阅读说明：本技术 一种荷叶总黄酮的提取方法 (Method for extracting total flavonoids from lotus leaves ) 是由 吕颖捷 崔璀 彭培立 赵永梅 李元元 吴妍 霍娜娜 李锦� 张娜娜 唐贝 于 2020-07-14 设计创作，主要内容包括：本发明属于黄酮提取方法领域,特别涉及一种荷叶总黄酮的提取方法。包括荷叶粉制备,乙醇提取,超声波提取,酶解,浓缩干燥。本发明的乙醇-超声波-酶提取的三级提取顺序能够高效的提取荷叶总黄酮。(The invention belongs to the field of flavone extraction methods, and particularly relates to an extraction method of lotus leaf total flavone. Comprises the steps of lotus leaf powder preparation, ethanol extraction, ultrasonic extraction, enzymolysis, concentration and drying. The three-stage extraction sequence of ethanol-ultrasonic-enzyme extraction can efficiently extract the lotus leaf total flavonoids.)

1. The method for extracting the lotus leaf total flavonoids is characterized by comprising the following steps:

s1, drying and crushing lotus leaves, and sieving the lotus leaves with a 30-50-mesh sieve to obtain lotus leaf powder;

s2, preheating ethanol with the volume concentration of 60-80% to 45-65 ℃, and mixing the ethanol with the lotus leaf powder obtained in the S1 according to the dosage ratio of 3 g: mixing 40-80ml, stirring for 30-60min to obtain first-stage extractive solution;

s3, adding alpha-tocopherol into the primary extract, uniformly mixing, and radiating for 10-40S at 45-65 ℃ under the power of 50-80W of ultrasonic waves to obtain a secondary extract;

the dosage ratio of the alpha-tocopherol to the first-stage extracting solution is 0.5 mg: 40-80 ml;

s4, naturally cooling the secondary extract to 30-45 ℃, preserving heat, adding extracting enzyme, adjusting the pH to 5-6, and performing enzymolysis for 2-4h to obtain a tertiary extract;

the dosage ratio of the extraction enzyme to the secondary extracting solution is 1-4 mg: 40-80 ml;

s5, filtering the tertiary extract to obtain a first filtrate and a first filter residue, continuously mixing the filter residue with a preheated ethanol solution, stirring, filtering for the second time to obtain a second filtrate and a second filter residue, combining the first filtrate and the second filtrate, concentrating and drying to obtain an extract, and recovering ethanol;

s6, adding distilled water into the extract obtained in S5 to obtain a total flavone water-soluble extract;

the dosage ratio of the extract to distilled water is 1-3 g: 10 ml.

2. The method for extracting total flavonoids from lotus leaves as claimed in claim 1, wherein in S1, the drying temperature of lotus leaves is 50-80 ℃.

3. The method for extracting total flavonoids from lotus leaves according to claim 1, wherein in S4, the extraction enzyme is any one of cellulase and pectinase.

4. The method for extracting total flavonoids from lotus leaves as claimed in claim 1, wherein in S5, the concentration of the ethanol solution is 60-80% and the temperature is 45-65 ℃.

5. The method for extracting total flavonoids from lotus leaves as claimed in claim 1, wherein in S5, the concentration and drying mode after the first filtrate and the second filtrate are combined is one of vacuum drying, spray drying and freeze drying.

Technical Field

The invention belongs to the field of flavone extraction methods, and particularly relates to an extraction method of lotus leaf total flavone.

Background

The biological total flavonoids refer to flavonoid compounds, are a large class of natural products, widely exist in the plant world, and are effective components of a plurality of Chinese herbal medicines. The most common in nature are flavones and flavonols, others include dihydroflavons (alcohols), isoflavones, biflavones, flavanols, chalcones, aurones, anthocyanins, neoflavonoids, and the like. Since the development of free radical life science, flavonoids having strong antioxidant and free radical-eliminating effects have been paid unprecedented attention.

The lotus leaves are leaves of lotus of Nymphaeaceae, and have wide application in both edible and medicinal aspects, and the lotus leaves have pharmacological action because the lotus leaves contain various substances with medicinal properties, wherein, the lotus flavonoids have relatively high content and have the efficacies of antivirus, antioxidation, blood fat reduction, anticancer and the like. At present, the extraction method of the lotus flavonoids compounds mainly comprises a solvent extraction method, a microwave extraction method, an ultrasonic extraction method, an enzymolysis method and the like, the extraction rate of the lotus flavonoids compounds is low, most of the lotus flavonoids compounds are 1-5%, raw materials are wasted, and people rarely extract the lotus flavonoids compounds by combining different methods, so that the invention provides the extraction method of the lotus leaf total flavonoids.

Disclosure of Invention

The extraction method of the lotus leaf total flavonoids provided by the invention can efficiently extract the lotus leaf total flavonoids, and has a great application prospect.

The invention provides a method for extracting lotus leaf total flavonoids, which comprises the following steps:

s1, drying and crushing lotus leaves, and sieving the lotus leaves with a 30-50-mesh sieve to obtain lotus leaf powder;

s2, preheating ethanol with the volume concentration of 60-80% to 45-65 ℃, and mixing the ethanol with the lotus leaf powder obtained in the S1 according to the dosage ratio of 3 g: mixing 40-80ml, stirring for 30-60min to obtain first-stage extractive solution;

s3, adding alpha-tocopherol into the primary extract, uniformly mixing, and radiating for 10-40S at 45-65 ℃ under the power of 50-80W of ultrasonic waves to obtain a secondary extract;

the dosage ratio of the alpha-tocopherol to the first-stage extracting solution is 0.5 mg: 40-80 ml;

s4, naturally cooling the secondary extract to 30-45 ℃, preserving heat, adding extracting enzyme, adjusting the pH to 5-6, and performing enzymolysis for 2-4h to obtain a tertiary extract;

the dosage ratio of the extraction enzyme to the secondary extracting solution is 1-4 mg: 40-80 ml;

s5, filtering the tertiary extract to obtain a first filtrate and a first filter residue, continuously mixing the filter residue with a preheated ethanol solution, stirring, filtering for the second time to obtain a second filtrate and a second filter residue, combining the first filtrate and the second filtrate, concentrating and drying to obtain an extract, and recovering ethanol;

s6, adding distilled water into the extract obtained in S5 to obtain a total flavone water-soluble extract;

the dosage ratio of the extract to distilled water is 1-3 g: 10 ml.

Preferably, in S1, the lotus leaf drying temperature is 50-80 ℃.

Preferably, in S4, the extraction enzyme is any one of cellulase and pectinase.

Preferably, in S5, the ethanol solution has a concentration of 60-80% and a temperature of 45-65 ℃.

Preferably, in S5, the first filtrate and the second filtrate are combined and then concentrated and dried in one of vacuum drying, spray drying and freeze drying.

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

1. according to the technical scheme provided by the invention, the average extraction rate of the obtained total flavonoids is up to 15.02% by three-stage extraction and two-time filtration of the lotus.

2. According to the invention, the lotus is extracted according to the three-stage sequence of ethanol-ultrasonic-enzyme extraction, the sequence greatly improves the extraction rate of the total flavonoids in lotus leaves, and the three-stage sequence of the ethanol-ultrasonic-enzyme extraction is 3-9 times of the extraction rate of other sequences.

3. When the total flavone is extracted under ultrasonic wave, the damage of the ultrasonic wave to the activity of the total flavone can be relieved by adding the alpha-tocopherol, so that the extraction rate is improved.

Detailed Description

The following detailed description of specific embodiments of the invention is provided, but it should be understood that the scope of the invention is not limited to the specific embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention. The experimental methods described in the examples of the present invention are all conventional methods unless otherwise specified.