Ultrasonic extraction technology in plant extraction
Many natural products have their unique advantages in health care and treatment of diseases, so they have attracted more and more attention, and their application scope is also becoming more and more extensive. Due to the many drawbacks of traditional extraction methods that cannot meet actual needs, faster and more efficient extraction methods are needed in extraction. Ultrasonic extraction is a new type of physical extraction method, which is attracting attention because of its fast and efficient speed and low impact on nutritional value. Ultrasonic waves are mechanical waves with a vibration frequency higher than that of sound waves (20kHz) that propagate in elastic media. They can generate and transmit powerful energy and give great acceleration to media (such as solid small particles or aggregates). When the energy received inside the particles is sufficient to overcome the binding energy of the structure, the solid particles (or aggregates) are broken (or depolymerized), thereby promoting the dissolution of the active components in the cell: This energy acts on the liquid. When the vibration is in a sparse state, the liquid will tear into very small holes. These holes close instantly, and when closed, an instantaneous pressure of up to dozens of atmospheres is generated, which is called cavitation phenomenon. This hole phenomenon can refine various substances and produce milk solutions, accelerating the dissolution of the active components in the cell. In addition, the secondary effects of ultrasound, such as mechanical vibration, emulsification, diffusion, crushing, chemical effects, etc., can also accelerate the diffusion and release of the active components in the cell and make it fully mixed with the solvent for easy extraction. Now the following is an overview of the research results of ultrasound in recent years.
1 flavone
Guo Qingzhi et al. [1] optimized the ultrasonic extraction process of bitter gourd flavonoids by orthogonal test, and compared it with the traditional extraction method. The ultrasonic power, extraction time, material-liquid ratio were selected as the investigation factors, and three levels were designed for each factor. The change of ultrasonic power had the greatest impact on extraction, followed by extraction time and material-liquid ratio. Comprehensive consideration of various factors concluded that the ultrasonic extraction process conditions of bitter gourd flavonoids were extraction with 90% ethanol, ultrasonic power was 80W, extraction was 20min, and the material-liquid ratio was 1:30 (g: ml, the same below). Compared with the traditional extraction method, the extraction amount was 1.36 times that of the traditional method, and the extraction time was 1/9 of the traditional extraction method.
Lan Changyun et al. [2] studied the optimal extraction process of flavonoids from Sophora sophora by ultrasonic method, and investigated the effects of ethanol concentration, material-liquid ratio, ultrasonic-assisted extraction time, extraction temperature and other main factors on the extraction rate of flavonoids. The optimal extraction conditions of ultrasonic method were as follows: using 60% ethanol, extracting 30 minutes at a temperature of 75 ° C and a material-liquid ratio of 1:15, and extracting twice in a row, the total extraction rate of flavonoids could reach 99.84%. Finally, the optimal extraction process was determined by orthogonal method, and compared with the conventional thermal reflux extraction method. The results showed that ultrasonic method was better than the conventional thermal reflux extraction method.
Huang Suoyi et al. [3] The total flavonoids in Jiuli were extracted by ultrasonic wave. 95% ethanol was used as the extractant, and the content was determined by ultraviolet spectrophotometry. The content of total flavonoids in the sample was measured to be 1.0128mg/ml, and the collection rate was 102.5%. The flavonoids obtained by ultrasonic extraction and purification method have high purity.
Niu Lixin et al. [4] studied the extraction process of total flavonoids from the bulbs of Luodan by ultrasonic extraction. Taking the extraction rate as the index, the optimal extraction conditions were determined by single factor experiment and orthogonal experiment. Under 80% ethanol, 80 ℃, 1:30 material-liquid ratio, ultrasonic extraction for 40 minutes, the relative extraction rate of single total flavonoids reached 92.32%, and reached 99.25% for two consecutive times. Compared with the traditional method, it saves a lot of time. It is a reference method for the study and utilization of lily plants.
The total flavonoids in the male inflorescences of Populus tomentosa were extracted by ultrasonic intensification, and the selection of ultrasonic power, extraction time, material-liquid ratio, and extraction solution concentration was tested respectively. The effects of extraction time and material-liquid ratio on the yield of flavonoids were as follows: with the prolongation of time or the increase of material-liquid ratio, the yield showed a gradual improvement trend; with the increase of ethanol concentration, the yield of flavonoids gradually decreased; within a certain ultrasonic power range, the yield increased with the increase of power, but when a certain power was reached, the yield did not increase. The optimal process of ultrasonic extraction was: ethanol concentration of 70%, ultrasonic power of 150W, extraction time of 40min, material-liquid ratio of 1:30.
Deng Guanghui et al. [6] made a study on the extraction of flavonoids from hawthorn leaves by ultrasonic ethanol, using ethanol as the solvent, different ethanol concentrations, different treatment times, and different material-liquid ratios as the main investigation factors, and the extraction rate of total flavonoids in the soaked samples as the main investigation indicators to determine the optimal extraction conditions. It is concluded that ethanol concentration has the greatest influence on the extraction rate, followed by ultrasonic extraction time, and the material-liquid ratio has the least influence. And the optimal extraction conditions are: ethanol concentration 50%, ultrasonic action time 45 min, material-liquid ratio is 1:25. At this time, the extraction rate is 91.39%. Compared with conventional Soxhlet extraction, the extraction time and solvent usage are greatly reduced, and a higher extraction rate can be achieved.
2 alkaloids
Chu Zhibing et al. [7] determined the content of nicotine in tobacco by ultrasonic extraction-high performance liquid chromatography. The extraction method, solvent and optimal extraction time were optimized, and the ultrasonic extraction conditions for preparing nicotine analysis samples were determined: 0.4% NaOH solution was the solvent, the ratio of material to liquid was 1:40, and the extraction time was 4 h. The method for the determination of nicotine in tobacco has the characteristics of simplicity, rapidity, high precision and good reproducibility, and is suitable for the determination of nicotine content in tobacco and its preparations.
Zhang Zesheng et al. [8] used ultrasonic-assisted method to extract solanesol from tobacco leaves. The results of orthogonal experimental design showed that prolonging the ultrasonic time can effectively improve the extraction rate of solanesol. Increasing the ultrasonic power, increasing the material-liquid ratio, and increasing the extraction temperature can all improve the extraction rate of solanesol. The best extraction solvent isacetoneThe optimal process conditions were as follows: acetone was used as the extraction solvent, the ratio of material to liquid was 1:17.15, the temperature was 60 ℃, the extraction was 2 h, the ultrasonic power was 160W, and the extraction rate of solanesol was 94.7%. The main factors affecting the extraction rate of solanesol were the extraction time, followed by the extraction solvent and temperature, while the ultrasonic power and the ratio of material to liquid had little influence on the results.
Chen Zhihui et al. [9] compared the extraction rates of total alkaloids from the three methods of Soxhlet reflux, conventional extraction, and ultrasound. Compared with the extraction time and extraction rate, the ultrasonic extraction method is simple and fast, and the extraction rate is the highest. At the same time, using orthogonal test, different ultrasonic extraction time, different extraction temperature, and different extraction times as the main investigation factors, the optimal process conditions were obtained: using chloroform as the solvent, under the conditions of frequency 50 Hz and temperature 70 ℃, the extraction was shaken in the ultrasonic oscillator for 3 times for 30 minutes each time.
Yang Zipeng [10] investigated the extraction process of total alkaloids in pepper, and took the extraction rate of total alkaloids as the investigation index, and used orthogonal design experiments to optimize the optimal extraction conditions. The results showed that ethanol concentration had the greatest impact on the extraction rate of alkaloids, and the effect of reflux time was the smallest. The optimal extraction process was to use 75% ethanol as the extraction solvent, first ultrasonic extraction for 60 minutes, and then reflux extraction for 1 hour, and the total alkaloid extraction rate was 11%.
Li Chu et al. [11] compared three methods of extracting mistletoe alkali, including supercritical CO2 extraction, acid aqueous solution extraction, and ultrasonic-assisted extraction. The results showed that the extraction rate of mistletoe alkali using acid water extraction or ultrasonic-assisted extraction was generally higher than that of supercritical CO2 extraction. In contrast, ultrasonic-assisted extraction is simple and easy, and it is an effective extraction method. At the same time, the orthogonal test optimization design analysis was used to obtain that in the process of ultrasonic-assisted extraction of mistletoe alkali, the effects of ethanol volume fraction, ultrasonic time and material-liquid ratio on the extraction effect of mistletoe alkali were: ethanol volume fraction > ultrasonic time > solid-liquid ratio. The optimal process conditions for ultrasonic-assisted extraction were: ethanol volume fraction 100%, ultrasonic time 30 min, material-liquid ratio 1:30.
3 polysaccharides
Han Bingbing et al. [12] conducted a study on ultrasonic-enhanced extraction of jujube polysaccharides, and conducted grouping experiments on various factors of ultrasonic-assisted extraction process conditions. Under the conditions of material-liquid ratio of 1:6, temperature of 70 ° C and power of 64W, the extraction rate of polysaccharides was the largest, 98.2%.
Li Jinzhong et al. [13] used ultrasonic to extract yam polysaccharide, and studied the effects of ultrasonic power, ultrasonic-assisted extraction time, material-liquid temperature, and material-liquid ratio on the yield. On this basis, the orthogonal test of four factors and three levels was used to optimize the ultrasonic extraction process of yam polysaccharide. The optimal test conditions for ultrasonic extraction of yam polysaccharide were obtained: ultrasonic power 1000W, ultrasonic time 50min, extraction temperature 60 ℃, material-liquid ratio 1:12.5. Yam polysaccharide was extracted under these conditions, and the yield was 20.27%.
Sun Sulan [14] and others used ultrasonic technology to conduct a multi-factor study on the extraction process of Ganoderma lucidum tea bag polysaccharides, and improved the production process of the original Ganoderma lucidum tea bag brewed with water. The experimental conditions of ultrasonic extraction of Ganoderma lucidum tea bag polysaccharides by multi-factor investigation showed that the content of Ganoderma lucidum polysaccharides obtained by ultrasonic extraction of 0.5 to 1 h under the condition of pH = 2.0 was the most, and compared with the content of untreated polysaccharides, the crude polysaccharides obtained by ultrasonic extraction at 0.5 to 1 h increased by 10% to 20%.
Zhou Lianwen [15] et al. studied the extraction of polysaccharides from golden jujube residue by enzyme-ultrasonic extraction method. The effects of extraction time, extraction temperature, material-liquid ratio, pH, cellulase addition amount and extraction times on the extraction rate were studied by single factor experiment, and the optimal process conditions were determined as follows: material-liquid ratio 1:40, pH 5.5, extraction temperature 55 ℃, extraction time 20 min, cellulase addition amount 1.5%, polysaccharide extraction rate 37.13%. The method has high extraction rate, simple process, andextractStructural and physical properties are not affected.
Xiong Bing et al. [16] extracted pumpkin polysaccharide by ultrasonic-assisted extraction method, carried out a single factor test, and did an orthogonal test on this basis, and concluded that the most important factor affecting the extraction amount of pumpkin polysaccharide was ultrasonic frequency. From the single factor test and orthogonal experiment, it was obtained that 1:5 was used as the ratio of sample solution to ethanol dosage for precipitation pumpkin polysaccharide. Under the condition of 1:40 material-liquid ratio, the optimal process conditions for ultrasonic extraction were: ultrasonic frequency 13kHz, extraction time was 15min, pH of the extract was 10, and the extraction amount of pumpkin polysaccharide was 27.63mg/g.
4 pigments
Ma Lihua [17] and others extracted carotenoids from burdock by ultrasonic-microwave synergistic method, taking the degree of pulverization of material and material, the ratio of material to liquid, the microwave power, and the extraction time as the factors. The ultrasonic power is 40W, and the orthogonal test is carried out to determine the best extraction scheme. The test results show that the optimal conditions are that the ultrasonic power is 40W, the microwave power is 350W, the extraction time is 30s, the ratio of material to liquid is 1:25, and the particle size of burdock powder is 60 mesh. Ultrasonic - microwave synergistic extraction new technology and apparatus will combine direct ultrasonic vibration and open microwave two ways, make full use of the hole effect of ultrasonic waves and high energy effect of microwave, to achieve a low temperature and atmospheric pressure conditions for solid samples rapid, efficient and reliable pretreatment, compared with the traditional extraction method in addition to the device speed, energy consumption, small amount of solvent, high collection rate advantages, but also conducive to the extraction of polar and thermally unstable components, to avoid constant high temperature and high pressure extraction or decomposition caused by synthetic reaction, so as not to destroy the structure of the extracted organic molecules.
Xie Fengxia [18] and others studied the comparison between the extraction method and the ultrasonic extraction method to extract gardenia yellow pigment. Through orthogonal experiments, the optimal process conditions for the extraction of gardenia yellow pigment by ultrasonic method were determined: the extraction solvent was 50% ethanol aqueous solution, the extraction time was 1h, the extraction temperature was 20 ° C, the material-liquid ratio was 1:12, and the extraction order was 1. Under these conditions, the extraction rate of the pigment was 98.84%, and the color price of the product was 70.72. Compared with the traditional extraction method, the ultrasonic extraction of gardenia yellow pigment has the advantages of low extraction temperature and short time, and the extraction rate of the pigment product is high and the color price is high.
Gu Wenxiu et al [19] used ultrasonic method to extract the pigment of Wufan leaves. According to the single factor test, the most important factor affecting the extraction of the pigment of Wufan leaves was the volume fraction of ethanol. The quadratic polynomial regression analysis was carried out on the orthogonal test results by computer and passed the fitting. The final optimized process conditions were: the extraction time was 41 minutes, and the solvent was 70%.Ethanol, the temperature is 73 ° C, the extraction times are once, and the material-liquid ratio is 1:3.5. The extraction rate under the optimal process conditions is 11.45%, and the experimental verification value is 11.43%. Compared with the conventional extraction method, the yield of the ultrasonic method is nearly double, and the solvent used is less, the extraction time is short, and the obtained pigment quality is higher.
Li Shan [21] et al. conducted an experiment on ultrasonic assisted extraction of yellow pigment in peanut shells. Using different extracts, material-liquid ratio, extraction time, and extraction times as single factors, the absorbance of the extract measured by ultraviolet spectrophotometer at 355nm was used as the experimental index. The optimal conditions for ultrasonic extraction of yellow pigment in peanut shells were determined as follows: 70% ethanol was used as the extraction solvent, the ratio of material to liquid was 1:9, the ultrasonic frequency was 20kHz, each extraction was 8 minutes, and the extraction was twice, and the yield of crude pigment was 4.3%. Compared with the heating reflux method and the soaking method, the ultrasonic extraction method has the advantages of high efficiency, short time, and energy saving.
In recent years, ultrasonic extraction of natural Chinese medicine extracts has made great progress as an aspect of ultrasonic technology, and the extraction method has also developed from a single use of ultrasonic to ultrasonic-assisted extraction and ultrasonic synergy with other technologies for extraction. From the research results, ultrasonic extraction technology has reached a satisfactory level in terms of extraction yield. In the future research on ultrasonic extraction, we should focus on the in-depth study of its mechanism in the extraction of various substances, summarize and organize to form a complete ultrasonic extraction system, and do more in-depth research in combination with more technologies and auxiliary extraction to promote ultrasonic extraction into the application field.
References:
[1] Guo Qingzhi, Zhao Erlao, Chen Jie. Optimization of ultrasonic extraction process of flavonoids from bitter gourd by orthogonal test. Winemaking Technology, 2007, (1): 36-37
LAN CHANGYUN, ZHOU CHONGSONG, FAN Biwei, et al. Ultrasonic extraction of flavonoids from Phyllostachys sophora L. Natural Products Research and Development, 2005,17 (1): 55-58
[3] Huang Suoyi, Yang Wenhui, Li Weibin, et al. Ultrasonic extraction of total flavonoids of Jiulixiang and its identification. Shi Zhen Guoyi Sinopharm, 2006, 17 (3): 395-396
Niu Lixin, Li Zhannian, Li Hongjuan, et al. Ultrasonic extraction of total flavonoids from Luodan bulbs. Chinese Herbal Medicine, 2007, 30 (1): 85-88
Shi Xingang, Wang Xiao, Geng Yanling, et al. Ultrasonic-enhanced extraction of total flavonoids from male inflorescences of Populus tomentosa. Journal of Shandong Institute of Light Industry, 2004,18 (2): 56-59
Deng Guanghui, Zhou Gui, Liu Rongcheng. Ethanol extraction of flavonoids from hawthorn leaves by ultrasonic method. Guangxi Light Industry, 2007, (1): 1-2
[7] Chu Zhibing, Zhou Xinguang, Shui Hengfu, et al. Determination of nicotine content in tobacco by ultrasonic extraction 2 high performance liquid chromatography. Chemical Technology and Development, 2007, 36 (2): 46-48
