How to make powder from Alisma orientalis (Sam.) Juzep. extract?

1. Introduction

Alisma orientalis (Sam.) Juzep., also known as Oriental Waterplantain Rhizome, has been widely used in traditional medicine. The extract of Alisma orientalis contains various bioactive components. Converting this extract into powder form can enhance its stability, ease of storage, and broaden its applications in pharmaceuticals, nutraceuticals, and cosmetics. This article will provide a comprehensive guide on how to make powder from Alisma orientalis extract.

2. Extraction of Alisma orientalis

2.1. Selection of raw materials

The quality of raw materials is crucial for obtaining a high - quality extract. Alisma orientalis should be carefully selected. It is advisable to choose fresh, mature, and disease - free plants. The rhizomes are the main parts used for extraction. They should be cleaned thoroughly to remove soil, debris, and other impurities.

2.2. Solvent extraction

1. One common method is to use water as a solvent. Cut the cleaned Alisma orientalis rhizomes into small pieces. Then, soak them in water at an appropriate ratio, for example, 1:5 (rhizome: water) for a certain period, usually around 2 - 4 hours.
2. Another option is to use organic solvents such as ethanol. Ethanol extraction can be more effective in extracting certain lipophilic components. The rhizomes are soaked in ethanol with different concentrations, typically ranging from 50% - 95% ethanol, for a similar time period as in water extraction.
3. After soaking, the mixture is heated gently under reflux conditions. For water extraction, the temperature can be maintained at around 80 - 90 °C, while for ethanol extraction, a slightly lower temperature, around 70 - 80 °C, may be appropriate to avoid excessive evaporation of ethanol. The reflux time can be 1 - 3 hours depending on the scale of extraction.

2.3. Pressurised liquid extraction

Pressurised liquid extraction (PLE) is also an option. This method uses high - pressure and temperature to accelerate the extraction process.

• The Alisma orientalis rhizomes are placed in a PLE device, and a suitable solvent, such as water or ethanol - water mixtures, is added.
• The pressure can be set between 10 - 20 MPa, and the temperature can be adjusted between 100 - 150 °C. These conditions can significantly reduce the extraction time, usually to within 30 minutes - 1 hour.

3. Purification of the extract

3.1. Filtration

After extraction, the extract needs to be purified. Filtration is the first step.

• Use a filter paper or a filtration device with an appropriate pore size, such as a Buchner funnel with a filter paper of medium porosity. This can remove large particles, undissolved plant debris, and other solid impurities from the extract.
• If a more refined filtration is required, membrane filtration can be considered. Ultra - filtration membranes with different molecular weight cut - offs can be used to separate proteins, polysaccharides, and other macromolecules from the extract, depending on the desired purity of the final powder.

3.2. Centrifugation

Centrifugation can further purify the extract.

• Transfer the filtered extract to centrifuge tubes. Set the centrifuge at an appropriate speed, usually between 3000 - 8000 rpm, and centrifuge for 10 - 30 minutes.
• This process can separate fine particles, emulsions, and other substances that are not removed by filtration. The supernatant obtained after centrifugation contains the purified extract.

3.3. Precipitation

Precipitation can be used to remove some specific components.

• For example, if there are excessive tannins in the extract, adding a suitable precipitating agent such as lead acetate (caution should be taken as lead acetate is toxic) in a controlled amount can precipitate tannins. After precipitation, the mixture needs to be filtered again to remove the precipitate.
• Another method is to use ethanol precipitation for polysaccharides. By adding a large amount of ethanol (usually 80% - 90% ethanol) to the extract, polysaccharides can be precipitated out. The precipitate can be collected by centrifugation or filtration, and the supernatant can be further processed for powder production.

4. Drying of the purified extract

4.1. Spray drying

Spray drying is a popular method for converting liquid extracts into powder.

• The purified extract is first atomized into fine droplets through a nozzle. The droplet size can be controlled by adjusting the nozzle parameters.
• Hot air is then introduced into the drying chamber. The temperature of the hot air is typically maintained between 150 - 200 °C. The fine droplets are rapidly dried by the hot air, and the water or solvent in the droplets is evaporated, leaving behind dry powder particles.
• The dried powder is then collected in a cyclone separator or a filter bag at the bottom of the drying chamber.

4.2. Freeze - drying

Freeze - drying, also known as lyophilization, is another effective drying method.

• The purified extract is first frozen at a very low temperature, usually below - 40 °C. This freezing process causes the water or solvent in the extract to form ice crystals.
• Then, under vacuum conditions, the ice crystals are sublimated directly from the solid state to the gas state without passing through the liquid state. The sublimation process is carried out at a relatively low temperature, usually between - 20 - 0 °C, which helps to preserve the bioactive components of the extract.
• The dried product obtained after freeze - drying is a porous, fluffy powder with good rehydration properties.

4.3. Vacuum drying

Vacuum drying can also be used for drying the purified extract.

• The extract is placed in a vacuum drying oven. The vacuum is created to reduce the pressure inside the oven, which lowers the boiling point of water or solvent in the extract.
• The temperature for vacuum drying is usually set between 50 - 80 °C. This relatively low - temperature drying helps to prevent the degradation of bioactive components while effectively removing the water or solvent from the extract.
• After the drying process is completed, the dried powder can be collected from the drying oven.

5. Quality control of the powder

5.1. Determination of active ingredients

• Various analytical methods can be used to determine the content of active ingredients in the powder. For example, high - performance liquid chromatography (HPLC) can be used to quantify the levels of specific bioactive compounds in Alisma orientalis powder, such as alisol A, alisol B, etc.
• Gas chromatography - mass spectrometry (GC - MS) may be applicable for analyzing volatile components in the powder.

5.2. Physical properties assessment

• The physical properties of the powder, such as particle size distribution, bulk density, and flowability, need to be evaluated. Particle size analysis can be carried out using laser diffraction or sieving methods. The bulk density can be measured by weighing a known volume of powder.
• Flowability can be determined by observing the powder's ability to flow through a funnel or other flow - testing devices. Good flowability is important for applications such as encapsulation or formulation in pharmaceuticals and nutraceuticals.

5.3. Microbiological testing

• Microbiological testing is essential to ensure the safety of the powder. Tests for total viable count, yeast and mold count, and the presence of specific pathogens such as Escherichia coli and Salmonella should be carried out.
• If the powder fails to meet the microbiological safety standards, appropriate sterilization or decontamination methods need to be implemented, such as gamma - irradiation or heat treatment under controlled conditions.

6. Conclusion

Making powder from Alisma orientalis extract involves a series of processes, including extraction, purification, and drying. Each step is crucial for obtaining a high - quality powder with desirable properties. Quality control measures are also necessary to ensure the safety and efficacy of the final product. By following the methods described in this article, it is possible to produce Alisma orientalis extract powder suitable for a variety of applications in different fields.

FAQ:

Q1: What are the common extraction methods for Alisma orientalis (Sam.) Juzep.?

There are several common extraction methods for Alisma orientalis. One is the solvent extraction method, where suitable solvents such as ethanol or water are used to extract the active components from the plant material. Another method could be Soxhlet extraction, which is often used for more efficient and continuous extraction. Maceration is also a traditional method, where the plant material is soaked in a solvent for a certain period to allow the extraction of the desired substances.

Q2: Why is purification necessary when making powder from the extract?

Purification is necessary when making powder from Alisma orientalis extract for several reasons. Firstly, the extract may contain impurities such as other plant metabolites, proteins, or resins that are not the desired active components. These impurities can affect the quality, stability, and efficacy of the final powder product. Purification helps to remove these unwanted substances, ensuring that the powder contains a higher concentration of the active and useful components, which is crucial for its intended applications, whether in the pharmaceutical, cosmetic or other industries.

Q3: What drying techniques are suitable for drying the Alisma orientalis extract before making it into powder?

Some suitable drying techniques include freeze - drying and spray - drying. Freeze - drying is a method that freezes the extract first and then removes the water under low pressure. This method is good for preserving the bioactivity of the components as it minimizes thermal degradation. Spray - drying involves spraying the extract into a hot drying medium, usually air. It is a relatively fast method and can produce fine powders with good flowability. Vacuum drying can also be used, which helps to remove moisture under reduced pressure, reducing the risk of oxidation during the drying process.

Q4: How can we ensure the quality of the powder made from Alisma orientalis extract?

To ensure the quality of the powder made from Alisma orientalis extract, several steps can be taken. Firstly, starting with high - quality raw materials is crucial. The extraction process should be carefully controlled, including parameters such as temperature, solvent concentration, and extraction time. During purification, appropriate purification methods should be selected based on the nature of the impurities and the target components. Drying should also be done properly to avoid issues like over - drying or under - drying. Additionally, quality control tests such as analysis of active ingredient content, microbial testing, and physical property assessment (such as particle size and powder flowability) should be carried out.

Q5: What are the potential applications of the powder made from Alisma orientalis extract?

The powder made from Alisma orientalis extract has several potential applications. In the pharmaceutical field, it may be used in the development of drugs for treating various diseases, especially those related to fluid regulation in the body, as Alisma orientalis has diuretic properties. In the cosmetic industry, it can be incorporated into skincare products for its potential antioxidant and anti - inflammatory effects. It may also find applications in the food supplement industry, where it can be used as a natural ingredient with potential health - promoting properties.

Related literature

• Study on the Extraction and Activity of Alisma orientalis Components"
• "Purification Methods for Alisma orientalis Extract and Their Impact on Quality"
• "Drying Techniques in the Preparation of Alisma orientalis Extract Powder"