Fritillaria cirrhosa D. Don, also known as rolled leaf Fritillaria, is one of the sources of Fritillaria medicinal materials. It has the effects of clearing heat and moistening the lungs, resolving phlegm and cough, dispersing nodules and eliminating carbuncles. It mainly contains alkaloids and nucleosides, and starch accounts for 70% to 80% of the total biomass of Fritillaria. It grows in alpine shrub meadow areas with an altitude of 3200~4600 m, and sunny grass slopes with moist soil are mainly distributed in Sichuan, Xizang, Yunnan and other places. Commercial medicinal materials are mainly wild resources. However, due to the strict requirements of the growth environment and low biological yield of Fritillaria chuanxiong, coupled with excessive excavation, the wild resources of the original plant of Fritillaria chuanxiong have sharply declined. The National Key Protected Wild Plant List (released in 2021) has included it in the second-class protected wild plants. At present, the industrial cultivation of Fritillaria thunbergii is developing rapidly, and its related cultivation techniques have been studied extensively and are becoming increasingly mature. It will gradually realize the production and medicinal use of Fritillaria thunbergii medicinal materials, and alleviate the market pressure of insufficient supply of medicinal materials caused by the reduction of wild resources. Origin processing is the source of production and quality formation of Fritillaria thunbergii medicinal materials, and is an important link in the production and quality formation of Fritillaria thunbergii medicinal materials. At present, the initial processing methods of Fritillaria thunbergii in the production area generally adopt traditional methods such as sun drying and drying, which have problems such as small scale dispersion, outdated technical equipment, long drying cycle, and difficult control of the drying process. With the expansion of the cultivation scale of Fritillaria thunbergii, the cultivated products will gradually enter the market. Traditional processing methods can no longer meet the production needs of cultivated products. Therefore, researching new processing techniques for cultivating Fritillaria thunbergii has become an urgent problem that needs to be solved in the industry.

In recent years, the industrialization level of traditional Chinese medicine production process has been continuously improved, and modern drying technology has gradually been introduced and promoted in the production areas of traditional Chinese medicine, such as Sanqi, Ginseng, Angelica sinensis, etc., which not only improves the processing and drying rate of their production areas, but also ensures their quality. Among the medicinal herbs of Fritillaria, only Fritillaria thunbergii has relevant research reports, and there is no research or application in Fritillaria thunbergii. Therefore, based on the above issues, this experiment compares the comprehensive effects of traditional sun drying, hot air drying, vacuum drying, and vacuum freeze-drying on the appearance and internal quality of Fritillaria thunbergii medicinal materials. Multiple indicators are used to evaluate the quality of Fritillaria thunbergii dried by different drying methods, and cluster analysis, principal component analysis, and other methods are used for comprehensive quality evaluation. The aim is to provide theoretical reference for the introduction and promotion of new drying and processing technologies in the production areas of Fritillaria thunbergii cultivation.

The initial processing in the production area is an important process that affects the production and quality of Fritillaria thunbergii medicinal materials. Fritillaria thunbergii has special properties and is difficult to dry and control. During the drying process, it is prone to produce oil seeds, yellow seeds, etc. In addition, the bulbs of cultivated products are larger in size and have certain changes in appearance, shape, and texture, making it more difficult to control the characteristics of the medicinal materials. It is also prone to problems such as yellowish, rough surface color, and insufficient powder. At present, the drying method of Fritillaria thunbergii is still mainly the traditional sun drying method, which has certain limitations for the rapid development of the Fritillaria thunbergii cultivation industry. How to achieve simple and efficient drying while maintaining good medicinal properties and high ingredient content as much as possible is an urgent problem to be solved. This experiment compared the effects of traditional sun drying methods and modern newly introduced hot air drying technology, vacuum drying technology, and vacuum freeze-drying technology on the appearance and internal quality of Fritillaria thunbergii in the production area. The results showed that although traditional drying methods have certain advantages in terms of appearance, they are easily affected by the environment and time-consuming, and alkaloid components are easily lost. Freeze drying method can better maintain the appearance of medicinal materials, with the highest starch content and total alkaloid content. The reason may be that freeze-drying avoids the oxidation and decomposition of dried substances caused by high temperature and atmospheric pressure evaporation, and can largely maintain the original nutritional components and high effective components of medicinal materials; Hot air drying (50-55 ℃) can improve the drying rate, shorten the drying time, and maintain the appearance and reduce the loss of effective ingredients. However, for medicinal materials that are killed at 105 ℃ or dried at 60 ℃, the starch particles undergo gelatinization, and the texture easily changes from powdery to keratinous. At the same time, it accelerates the loss of alkaloids and the decomposition of starch into sugars. Although this drying method is fast, it has a significant impact on its appearance, shape, and effective ingredients, so it is not suitable for drying Fritillaria thunbergii. It can be seen that temperature is the key factor causing changes in the physicochemical properties and biological activity of medicinal materials.
The empirical identification of traditional Chinese medicinal materials is based on “distinguishing appearance and quality”. Modern research has shown that the characteristics of traditional Chinese medicinal materials are important indicators for evaluating their quality, such as the high content of active ingredients such as benzoic acid when the surface of benzoin is yellow white to yellow brown and the cross-section is ivory white. However, traditional understanding suggests that Fritillaria is best when the bulbs are intact, uniform, white in color, and have a powdery appearance. However, there is a lack of quantitative detection methods. Therefore, this study introduced the principle of color analysis and starch content to objectively quantify the color and powdery appearance of Fritillaria. The results showed that Fritillaria has a slightly white color, and its total alkali content and starch content are relatively high. However, due to the limited number of dried samples and incomplete analysis of chemical composition types in this experiment, it is still necessary to establish a more comprehensive multi index comprehensive evaluation method and collect a large number of samples for verification in predicting the correlation between color difference values and effective ingredients.
In summary, the drying method is an important factor affecting the appearance and internal quality of medicinal materials. Traditional sun drying has certain limitations in the production and processing of Fritillaria thunbergii, as it is only suitable for smaller bulbs and ensures sufficient sunlight. The medicinal materials obtained by hot air drying method are most similar in appearance or quality to traditional sun drying. On the basis of ensuring the appearance and characteristics of the medicinal materials to a certain extent, it can not only reduce the loss of effective ingredients, but also improve drying efficiency, reduce drying time, and save time and cost for large-scale production. It is recommended to use hot air drying at 50-55 ℃ as the origin drying method in production. At the same time, freeze-drying can preserve the active ingredients to a large extent, so when extracting the active ingredients of Fritillaria, this method can be used for drying. However, freeze-dried medicinal materials have a loose and bubbly texture, large and numerous gaps in the cross-section, and special management should be paid to avoid moisture during later packaging and storage.