A method for post-harvest processing of Gentiana yunnanensis

Abstract

The present invention discloses a post-harvest processing method for Gentiana yunnanensis. The method comprises: cleaning the soil of freshly harvested Gentiana yunnanensis with water, removing the above-ground parts of the Gentiana yunnanensis, blanching the roots in 40-70°C hot water for 1-5 minutes, and then drying the blanched roots in an oven until dry, with the moisture content meeting the pharmacopoeial standard, i.e., not exceeding 9.0%, to obtain the Gentiana yunnanensis medicinal material. Compared with traditional methods, the present method can increase the gentiopicroside content in the Gentiana yunnanensis by 9.30% and the swedeoside content by 14.29%. Compared with existing heating and microwave treatments, the present method has simpler operating steps, lower production costs, and is suitable for farmers.

Description

Technical Field

[0001] The invention belongs to the technical field of agricultural product processing, and particularly relates to a post-harvest processing method of Gentiana yunnanensis. Background Art

[0002] Gentiana rigescens Franch., a perennial herb in the Gentianaceae family, is commonly known as "hard gentian." Its roots and rhizomes are used medicinally, making it one of the basal plants of the traditional Chinese medicine gentian. It has anti-inflammatory, analgesic, anti-apoptotic, liver failure prevention, choleretic, and antibacterial properties. Its main active ingredients are secoiridoid compounds, including loganin, scutellarin, scutellariamarin, and gentiopicroside. Iridoid compounds are unstable and susceptible to degradation reactions due to environmental factors. Post-harvest drying in the wild typically involves removing the stems and leaves after harvest, cleaning them from dirt, and then sun-drying or drying them in the shade. This process is highly arbitrary and subject to variable environmental factors, leading to significant variations in the content of active ingredients during the post-harvest drying process. Xu Qiuxia et al. compared the gentiopicroside content in raw, shade-dried, sun-dried, and oven-dried gentiana stored for one month and found that, compared with the raw material, all treatment methods resulted in gentiopicroside degradation. Shade-dried gentiana showed the least gentiopicroside loss, while sun-dried gentiana showed the greatest loss. The gentiopicroside content in oven-dried samples was intermediate between shade-dried and sun-dried gentiana (Xu Qiuxia et al., China Pharmacy, 2013). Wang Xijun et al. processed gentiana using three methods: drying at 45°C, 55°C, and 65°C, drying outdoors in the sun, and drying indoors. Their analysis of gentiopicroside content found that shade-dried gentiana had the highest gentiopicroside content, followed by sun-dried gentiana, and oven-dried gentiana had the lowest gentiopicroside content (Wang Xijun et al., Chinese Pharmaceutical Journal, 2004). Therefore, we can see that the medicinal components of Gentiana yunnanensis are severely degraded during the post-harvest drying process, which will directly affect the quality of Gentiana yunnanensis medicinal materials and lead to poor medicinal efficacy.

[0003] Currently, Zuo Zhitian et al. compared the content of active ingredients in Yunnan Gentiana scabra dried using nine different methods, including shade drying and blanching followed by shade drying. Analysis of the results revealed that shade-dried Yunnan Gentiana scabra had the highest gentiopicroside content (Zuo Zhitian, Journal of Southwest Agricultural Sciences, 2017). Previous research indicates that shade drying promotes the accumulation of gentiopicroside. However, shade drying takes a long time, with field research revealing that it takes 14-30 days. Consequently, this method is inefficient and difficult to implement on a large scale due to limited space. Furthermore, widespread mold and rot can occur in rainy weather. Wang Cong's research has shown that microwave vacuum drying can reduce the loss of active ingredients in Yunnan Gentiana scabra (Wang Cong, Shaanxi Agricultural Sciences, 2016). However, microwave drying and other methods require significant equipment investment, resulting in high production costs and prohibitive large-scale implementation by farmers in producing areas. Research by Rao Gaoxiong et al. has shown that treating Gentiana yunnanensis with exposure to the sun or baking at 80°C can reduce gentiopicroside loss (Rao Gaoxiong et al., Journal of Yunnan University of Traditional Chinese Medicine, 2002). However, the Yunnan Gentiana yunnanensis harvest season is often rainy, making it difficult to achieve the conditions for exposing all the herbs to the sun during the harvest period. Although heat drying can be achieved by constructing a drying room, according to research, the typical baking temperature in home-built drying rooms is 50-70°C, making it difficult to achieve the high temperature of 80°C. Therefore, developing a "refined" postharvest drying method that is easy for farmers to operate has far-reaching significance for the preparation of high-quality Chinese medicinal raw materials and stable Chinese medicine preparations. Summary of the Invention

[0004] The present invention aims to overcome the deficiencies in the prior art and provides a post-harvest processing method for Gentiana yunnanensis.

[0005] In order to achieve the above object, the technical solution provided by the present invention is:

[0006] The post-harvest processing method of the Yunnan Gentiana ginseng comprises cleaning the soil of the fresh Yunnan Gentiana ginseng with water after excavation, removing the above-ground part of the Yunnan Gentiana ginseng, placing the roots of the Yunnan Gentiana ginseng in hot water at 40-70°C, preferably 40°C, and blanching for 1-5 minutes, preferably 3.5-5.0 minutes, and then placing the blanched Yunnan Gentiana ginseng roots in an oven and drying them to a moisture content of ≤9.0% (the moisture content meets the pharmacopoeia standard), thereby obtaining the Yunnan Gentiana ginseng medicinal material.

[0007] Preferably, the oven temperature is 40-70°C.

[0008] More preferably, the oven temperature is 60°C.

[0009] Compared with the prior art, the present invention has the following beneficial effects:

[0010] 1. To address the serious loss of gentiopicroside, the main active ingredient, during the initial processing of Yunnan Gentiana, we have experimentally combined blanching and drying to achieve significant results in the post-harvest processing of Yunnan Gentiana.

[0011] 2. Previous research has shown that the effect of different treatments on the gentiopicroside content in gentian is as follows: indoor shade drying > outdoor sun drying > oven drying. The combined blanching and oven drying treatments not only effectively increased the retention of gentiopicroside, but also increased the gentiopicroside content by 9.30% and the swertrin content by 14.29% compared to shade-dried gentian.

[0012] 3. Previous studies have shown that drying at 80°C can reduce the degradation of gentiopicroside. This operation can lower the drying temperature and reduce production costs.

[0013] 4. Compared with the heating, microwave and other treatments currently under research, the operation steps are simpler, the production cost is lower, and it is suitable for farmers to operate.

[0014] In summary, compared with traditional methods, this method can increase the gentiopicroside content in gentian by 9.30% and the swertiacoside content by 14.29%; compared with current heating, microwave and other treatments, the operation steps of the present invention are simpler, the production cost is lower, and it is suitable for farmers to operate. DETAILED DESCRIPTION

[0015] Example 1

[0016] Five samples of freshly harvested Gentiana yunnanensis were collected, each containing five plants. After washing with water to remove mud and removing the aboveground parts, the roots were blanched in 40°C water for 5 minutes. After removal, the roots were oven-dried at 60°C until dry. The active ingredient content of Gentiana yunnanensis, as determined by HPLC, was as follows: loganinic acid (0.505±0.008%), swedemarin (0.243±0.004%), gentiopicroside (7.290±0.065%), and swedemarin (0.112±0.019%). The traditional shade-dried Gentiana yunnanensis had loganinic acid (0.502±0.003%), swedemarin (0.242±0.005%), gentiopicroside (6.667±0.015%), and swedemarin (0.098±0.006%). The content of gentiopicroside increased by 9.30%, and the content of swertiacoside increased by 14.29%.

[0017] Example 2

[0018] Five freshly harvested Gentiana yunnanensis roots, each containing five plants, were collected. After washing with water to remove mud and removing the aboveground parts, the roots were blanched in 50°C water for 1.00 min and then dried in a 70°C oven until dry. The medicinal material was obtained. HPLC analysis revealed the following active ingredient contents: loganinic acid (0.502±0.078%), swedemarin (0.265±0.002%), gentiopicroside (6.807±0.075%), and swedemarin (0.100±0.009%). Traditionally shade-dried Gentiana yunnanensis had loganinic acid (0.500±0.002%), swedemarin (0.241±0.005%), gentiopicroside (6.659±0.008%), and swedemarin (0.095±0.005%). The content of gentiopicroside increased by 2.22%, the content of swedeside increased by 5.26%, and the content of swedemarin increased by 9.90%.

[0019] Example 3

[0020] Five samples of freshly harvested Gentiana yunnanensis were collected, each containing five plants. After washing with water to remove mud and removing the aboveground parts, the roots were blanched in 70°C water for 3.88 minutes and then dried in a 40°C oven until dry. HPLC analysis revealed the following active ingredient contents in Gentiana yunnanensis: loganinic acid (0.519±0.010%), swedemarin (0.240±0.006%), gentiopicroside (6.800±0.090%), and swedemarin (0.099±0.003%). In Gentiana yunnanensis dried in the traditional shade, loganinic acid (0.497±0.008%), swedemarin (0.239±0.004%), gentiopicroside (6.676±0.004%), and swedemarin (0.090±0.001%) were found. The content of loganinic acid increased by 4.43%, the content of gentiopicroside increased by 1.86%, and the content of swertiacoside increased by 10.00%

[0021] Example 4

[0022] (1) Hot stamping + drying group

[0023] Five portions of freshly harvested Gentiana yunnanensis were collected, each with five plants. The plants were washed with water to remove mud and the aerial parts were removed. The roots of Gentiana yunnanensis were blanched in 40°C hot water for 5 minutes, removed, and dried in a 60°C oven until dry, thereby obtaining the Gentiana yunnanensis medicinal material.

[0024] (2) Hot blanching + shade drying group

[0025] Five portions of freshly harvested Gentiana yunnanensis were collected, each with five plants. The plants were washed with water to remove mud and the above-ground parts were removed. The roots of Gentiana yunnanensis were blanched in hot water at 40°C for 5 minutes, taken out, and placed in a dark place indoors to dry in the shade, thereby obtaining the Gentiana yunnanensis medicinal material.

[0026] (3) Drying group

[0027] Five portions of freshly harvested Gentiana yunnanensis were collected, each with five plants. The plants were washed with water to remove mud, and the above-ground parts were removed. The roots of Gentiana yunnanensis were dried in an oven at 60°C to obtain Gentiana yunnanensis medicinal materials.

[0028] (4) Blanching + sun drying group

[0029] Five portions of freshly harvested Gentiana yunnanensis were collected, each with five plants. The plants were washed with water to remove mud and the above-ground parts were removed. The roots of Gentiana yunnanensis were blanched in hot water at 40°C for 5 minutes, taken out, and exposed to sunlight outdoors to obtain the Gentiana yunnanensis medicinal material.

[0030] (5) Sun-dried group

[0031] Five portions of freshly harvested Gentiana yunnanensis were collected, each with five plants. The plants were washed with water to remove mud, the above-ground parts were removed, and the roots of Gentiana yunnanensis were exposed to sunlight outdoors to obtain Gentiana yunnanensis medicinal materials.

[0032] (6) Shade-dried group

[0033] Take 5 parts of fresh Yunnan Gentiana after digging, with 5 plants in each part. Wash with water to remove mud, remove the above-ground parts, and place the roots of Yunnan Gentiana in a dark place indoors to dry in the shade to obtain Yunnan Gentiana medicinal material.

[0034] See Table 1 for the list:

[0035] Table 1

[0036]

Claims

1. A method for post-harvest processing of Gentiana yunnanensis, characterized in that: The method comprises the following steps: using water to clean the soil of freshly dug Yunnan Gentiana, removing the above-ground part of the Yunnan Gentiana, placing the Yunnan Gentiana root in 40-70°C hot water for blanching for 1-5 minutes, and then placing the blanched Yunnan Gentiana root in an oven and drying it until the moisture content is ≤9.0%, thereby obtaining the Yunnan Gentiana medicinal material.

2. The method according to claim 1, wherein The temperature of the hot water is 40°C.

3. The method according to claim 1, wherein The hot soup treatment time is 3.5-5.0 minutes.

4. The method according to claim 1, wherein The oven temperature is 40-70°C.

5. The method according to claim 4, wherein The oven temperature is 60°C.

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