A method for efficiently extracting tea saponin from camellia seed meal

Abstract

A highly efficient method for extracting tea saponin from camellia oleifera seed meal is characterized by comprising the following steps: (1) mixing fatty acid A, fatty acid B, sodium hydroxide, and water to prepare an extractant, wherein fatty acid A is at least one of hexanoic acid, heptanoic acid, octanoic acid, or nonanoic acid, and fatty acid B is decanoic acid; (2) mixing the camellia oleifera seed meal with the extractant prepared in step (1) to extract tea saponin; and (3) after the extraction is completed, adding hydrochloric acid, centrifuging and separating the layers, and collecting the extract at the lower layer. The technical solution provided by the present invention has the following advantages: a high tea saponin extraction rate; the extractant does not contain volatile organic solvents and is easily recyclable and environmentally friendly; the extractant has good reusability and low extraction cost.

Description

Technical Field

[0001] The invention belongs to the technical field of extraction of natural products, and particularly relates to a method for efficiently extracting tea saponin from camellia seed cake. Background Art

[0002] Camellia oleifera seed meal, a major byproduct of the camellia oil processing industry, contains a variety of functional ingredients, including tea saponins, alkaloids, and polyphenols. Tea saponins, a natural surfactant with excellent solubility, antibacterial, and antioxidant properties, are widely used in daily chemicals, pharmaceuticals, and pesticides.

[0003] Currently, the industry primarily uses ethanol / water mixtures as extractants to extract tea saponins from camellia oleifera seed meal. However, these methods suffer from low tea saponin extraction yields, high solvent volatility, and a high extraction process risk. Furthermore, organic solvent recovery requires distillation, which is energy-intensive and costly. To address these issues, researchers have introduced deep eutectic solvents into tea saponin extraction (CN 115286680A, CN 115322241 A), offering advantages such as high extraction yields, low volatility, and enhanced safety. However, the separation and recovery of deep eutectic solvents is difficult, and the high cost of separation and recovery is a key factor limiting their large-scale application.

[0004] Therefore, developing a method for efficiently extracting tea saponins from camellia oleifera seed cake and achieving low-cost and low-energy recovery of the extractant to improve the economy and environmental friendliness of the tea saponin extraction process remains a key technical problem that needs to be solved by technicians in this field. Summary of the Invention

[0005] The present invention aims to provide a method for efficiently extracting tea saponin from camellia seed meal, which has the characteristics of high extraction rate, easy recovery of extractant, good reusability of extractant and low extraction cost.

[0006] The present invention provides a method for efficiently extracting tea saponin from camellia seed meal, which is characterized by comprising the following steps:

[0007] (1) preparing an extractant by mixing fatty acid A, fatty acid B, sodium hydroxide and water, wherein fatty acid A is at least one of hexanoic acid, heptanoic acid, octanoic acid or nonanoic acid, and fatty acid B is decanoic acid;

[0008] (2) mixing the defatted camellia seed meal with the extractant prepared in step (1) to extract tea saponin;

[0009] (3) After the extraction is completed, add hydrochloric acid, centrifuge and separate the layers, and collect the extract at the lower layer.

[0010] Furthermore, the molar ratio of the fatty acid A to the fatty acid B is 1:0.33-3.

[0011] Furthermore, the ratio of the total amount of the fatty acid A and the fatty acid B to the amount of sodium hydroxide is 1:1 to 1.05.

[0012] Furthermore, the mass ratio of the sodium hydroxide to water is 0.01-0.1:1.

[0013] Furthermore, in step (2), the mass ratio of camellia oleifera seed meal to the extractant is 1:20-50.

[0014] Furthermore, the extraction process of step (2) is specifically as follows: ultrasonicating the mixture of camellia seed meal and the extractant at 25-60° C. for 5-30 minutes.

[0015] Furthermore, the molar ratio of the hydrochloric acid to the sodium hydroxide is 1:0.95-1.

[0016] The mixed fatty acid involved in the technical solution provided by the present invention contains fatty acid A and fatty acid B, which can react with sodium hydroxide solution to generate mixed fatty acid sodium. The mixed fatty acid sodium is soluble in water, thereby forming a single-phase extractant with water. During the extraction process, the mixed fatty acid sodium helps tea saponin to seep from the camellia seed meal into the aqueous phase, thereby obtaining a higher extraction rate. After the extraction is completed, the mixed fatty acid sodium reacts with hydrochloric acid to regenerate the mixed fatty acid. The mixed fatty acid is insoluble in water, while the tea saponin is soluble in water. The mixed fatty acid and the tea saponin can be separated by simple centrifugal stratification. The technical solution provided by the present invention has the following advantages: (1) a high extraction rate for tea saponin; (2) the extractant does not contain volatile organic solvents and is easy to recycle and reuse, which is environmentally friendly; (3) the extractant has good reusability and low extraction cost. Implementation Method

[0017] The specific embodiments of the present invention will be described in further detail below. For those skilled in the art, the above and other objects, features and advantages of the present invention will be apparent from the detailed description of the present invention.

[0018] Example 1

[0019] An extractant was prepared by mixing 0.01 mol nonanoic acid, 0.03 mol decanoic acid, 0.04 mol sodium hydroxide, and 40 g water. After adding 1.5 g of defatted camellia oleifera seed meal, extraction was carried out under ultrasonic conditions at 50°C for 15 minutes. After the extraction, 10 mL of 4 mol / L hydrochloric acid was added to the mixture, and the mixture was thoroughly stirred and mixed. The liquid phase was separated by centrifugation. The upper oil phase was a mixture of nonanoic acid and decanoic acid, which could be used for the next batch of extraction. The lower aqueous phase was the tea saponin extract. UV spectrophotometry showed that the tea saponin extraction yield was 21.9% based on the mass of the camellia oleifera seed meal.

[0020] Example 2

[0021] An extractant was prepared by mixing 0.03 mol of octanoic acid, 0.01 mol of decanoic acid, 0.042 mol of sodium hydroxide, and 100 g of water. After adding 4 g of defatted camellia oleifera seed meal, extraction was carried out under ultrasonic conditions at 60°C for 10 minutes. After the extraction, 11 mL of 4 mol / L hydrochloric acid was added to the mixture, and the mixture was thoroughly stirred and mixed. The liquid phase was separated by centrifugation. The upper oil phase was a mixture of octanoic acid and decanoic acid, which could be used for the next batch of extraction. The lower aqueous phase was the tea saponin extract. UV spectrophotometry showed that the tea saponin extraction yield was 21.2% based on the mass of the camellia oleifera seed meal.

[0022] Example 3

[0023] An extractant was prepared by mixing 0.02 mol hexanoic acid, 0.02 mol decanoic acid, 0.04 mol sodium hydroxide, and 20 g water. After adding 0.75 g defatted camellia oleifera seed meal, extraction was carried out under ultrasonic conditions at 30°C for 30 minutes. After the extraction, 10 mL of 4 mol / L hydrochloric acid was added to the mixture, and the mixture was thoroughly stirred and mixed. The liquid phase was separated by centrifugation. The upper oil phase was a mixture of hexanoic acid and decanoic acid and could be used for the next batch of extraction. The lower aqueous phase was the tea saponin extract. UV spectrophotometry showed that the tea saponin extraction yield was 22.6% based on the mass of the camellia oleifera seed meal.

[0024] Example 4

[0025] Only 0.01 mol of nonanoic acid and 0.03 mol of decanoic acid were replaced by the mixture of nonanoic acid and decanoic acid recovered in Example 1. The other extraction and detection procedures were the same as in Example 1. The extraction rate of tea saponin was 21.7%.

[0026] Comparative Example 1

[0027] Only 0.01 mol of nonanoic acid and 0.03 mol of decanoic acid were replaced by 0.04 mol of nonanoic acid. The other extraction and detection procedures were the same as in Example 1. The extraction rate of tea saponin was 17.0%.

[0028] Comparative Example 2

[0029] Only 0.01 mol of nonanoic acid and 0.03 mol of decanoic acid were replaced by 0.04 mol of decanoic acid. The other extraction and detection procedures were the same as in Example 1. The extraction rate of tea saponin was 18.6%.

[0030] Comparative Example 3

[0031] Only 0.01 mol of nonanoic acid and 0.03 mol of decanoic acid were replaced by the same mass of ethanol. The other extraction and detection procedures were the same as in Example 1. The extraction rate of tea saponin was 15.5%.

[0032] The results of Examples 1-4 show that the extractant, primarily composed of mixed fatty acids and their sodium salts, exhibits a high extraction rate for tea saponins from camellia oleifera seed meal. Under mild conditions, the extraction rate exceeds 21%, approaching the theoretical tea saponin content in camellia oleifera seed meal. Furthermore, by modifying the extractant's hydrophilic and hydrophobic properties, the extractant can be rapidly separated and recycled, with the recovered extractant achieving an extraction rate substantially identical to that of fresh extractant, demonstrating its excellent reusability.

[0033] Combining the results of Example 1 with Comparative Examples 1-3, it can be seen that the extraction efficiency of tea saponin using the extractant with mixed fatty acids as the main component is higher than that of single fatty acids, and is superior to the traditional organic solvent ethanol. These results once again demonstrate that the extractant with mixed fatty acids as the main component has excellent extraction performance for tea saponin.

[0034] It should be understood that although the present invention has been clearly illustrated through the above embodiments, without departing from the spirit and essence of the present invention, technicians in the relevant technical field can make various corresponding changes and modifications based on the present invention, but these corresponding changes and modifications should all fall within the scope of protection of the claims of the present invention.

Claims

1. A method for extracting tea saponin from camellia seed meal, characterized in that: The steps include: (1) mixing fatty acid A, fatty acid B, sodium hydroxide and water to prepare an extractant, wherein fatty acid A is one of hexanoic acid, heptanoic acid, octanoic acid or nonanoic acid, and fatty acid B is capric acid; (2) mixing the defatted camellia seed meal with the extractant prepared in step (1) to extract tea saponin; (3) After the extraction is completed, hydrochloric acid is added, the layers are separated by centrifugation, and the extract at the lower layer is collected; The molar ratio of the fatty acid A to the fatty acid B is 1:0.33-3; In step (2), the mass ratio of camellia seed meal to the extractant is 1:20-50; The extraction process of step (2) is specifically as follows: ultrasonically treating the mixture of camellia seed meal and the extractant at 25-60° C. for 5-30 minutes.

2. The method for extracting tea saponin from camellia oleifera seed meal according to claim 1, characterized in that: The ratio of the total amount of the fatty acid A and the fatty acid B to the amount of sodium hydroxide is 1:1 to 1.

05.

3. The method for extracting tea saponin from camellia seed meal according to claim 1, characterized in that: The mass ratio of the sodium hydroxide to water is 0.01-0.1:

1.

4. The method for extracting tea saponin from camellia seed meal according to claim 1, characterized in that: The molar ratio of the hydrochloric acid to the sodium hydroxide is 1:0.95-1.