Overview of Capsaicin Extraction and Refining Process :
Natural plant pigments, as an important part of coloring agents, are widely used in food processing, medicine and cosmetics and other industries closely related to human health. Compared with synthetic coloring, natural plant coloring has sufficient raw materials, no toxic side effects on human body, and most of the natural coloring has certain physiological functions, such as natural β-carotene in anti-cancer, anti-cancer and prevention of cardiovascular diseases, etc. It has obvious effects. With the development of biotechnology, the research and development of natural plant pigments have received increasing attention, and their application has a wide range of prospects for development. Capsaicin is one of the hotspots in the study of natural pigments, which is a mixed pigment containing a variety of pigment components, including capsanthin (Capsanthin), capsaicin (Capsorubiu), cryptoxanthin (Crgtoxabthin), and other red pigments and yellow pigments such as violet yellow, yellow spirit.
The current chili pepper pigment products are mainly chili red pigment, which belongs to the carotenoids in the complex enkephalins, chili pepper red pigment, chili pepper red pigment and β-carotene mixture, which is safe and non-toxic, can be digested and absorbed by the human body, and in the human body is converted into vitamin A. Chili pepper red pigment appearance of dark red viscous oily liquid, can be arbitrarily soluble in vegetable oils, acetone, hexanethane, trichloromethane, Hexane, soluble in ethanol, slightly insoluble in propanetriol, insoluble in water, stable to acid and alkali (better stability in acidic environment), not easy to be destroyed under heating conditions, and has strong coloring power and good dispersion, but poor light resistance, oxidation resistance, wavelengths of 210 ~ 440nm, especially 285nm UV light can make it fade, add L-ascorbic acid can improve its light stability. The addition of L-ascorbic acid can improve its light stability, and the addition of flavonoids and polyphenols and other substances can be used as antioxidants. Chili red has bright color and high color value, and its color intensity is 10 times that of other pigments.
Based on the above characteristics of paprika pigment, scholars at home and abroad have carried out a lot of research on it, and several mature extraction and separation methods have been formed. The author of the chili pepper pigment extraction and refining technology and other aspects of the research results for a brief introduction, while looking forward to the future of chili pepper pigment research trends.
1 Several typical chili pepper pigment extraction and refining methods
1.1 Organic solvent extraction
According to the physicochemical properties of chili pepper pigment, the industry more to take the following method of extraction: the ripe and dried fruits of the Solanaceae plant chili pepper pericarp crushed with ethanol, acetone, isopropanol, or n-hexane and other extracts. Considering the natural red pepper contains paprika, capsaicin, chili oil and other components, of which capsaicin, capsaicin, that is, capsaicin has a spicy taste, high temperature produces irritating vapors, so in the process of refining chili pepper pigment must be removed. From the structure of capsaicin contains amide bonds, the molecule contains a hydroxyl group, is a polar compound, its crystals appear as a monoclinic prism or rectangular, melting point of 61 ℃, soluble in dilute ethanol, hexyl ether, acetone, ethyl acetate and other solvents and alkaline aqueous solution. Considering the different solubility of paprika mixture and capsaicin in different solvents, the solubility difference between the two can be utilized for dehazing. He Wenzhi et al [5] based on the principle of hexane extraction method, the use of paprika red pigment is easy to dissolve in hexane and capsaicin is more difficult to dissolve in the nature of hexane will be separated, the operating steps are as follows: weighing by the de-sticking, seeding, crushing of red pepper powder, acetone as the extractant for the atmospheric pressure extraction operation, the extract at a temperature of 90 ℃, the vacuum degree of 0.09 MPa conditions for The extract was concentrated by decompression distillation at a temperature of 90 ℃ under a vacuum of 0.09 MPa, and the acetone was recovered at the same time. The extraction of paprika with acetone is essentially a mass transfer process between liquid and solid through the interphase contact surface, and the speed of the mass transfer rate determines the size of the mass transfer equipment and the operation time. In order to improve the mass transfer rate, a Soxhlet extractor was used for the extraction of dried paprika in powder form. A certain amount of concentrated crude paprika product was weighed and extracted with a certain amount of n-hexane, and the experimental results are shown in Table 1.
Color value is defined as the absorbance of the extract per unit mass of raw material.
This method is simple, the recovery of pigment is large, the product yield is high, but the color value of the product is small. Since the negative correlation between color value and spiciness indicates that the method is not thorough enough, it can be used in the case of chili red as the main product and the requirement of capsaicin content is not very demanding. Zhang Zong'en et al. used acetone as solvent to extract and prepare chili oleoresin, the oleoresin yield was high, the color value was large, the content of capsaicin was low, and it was easy to separate. Using acetone (50%) solution with pH value greater than 10.37 for more than 5 times of dehomogenization extraction could obtain the red pigment without spicy taste. The method is simple and easy to operate, and the quality indexes of the obtained pigments are in accordance with FAO/WHO standards.
1.2 Column chromatography method It is reported that capsaicin in chili peppers can still feel spicy even if it is diluted 1:100000, which largely limits the application of chili pigment. Therefore, the removal of spicy components has become a key step in the extraction and separation of red pepper pigments. The separation of paprika pigment by silica gel column chromatography belongs to partition chromatography, which is based on the structural difference between pigment and chorine, and the different solubility in the stationary phase and eluent bound to silica gel, so the partition coefficients are different between the stationary phase and the eluent to achieve the separation effect. Yuan Qingyun studied the separation of paprika red pigment by silica gel column chromatography, and summarized the process as follows:
Pepper→selected→pulverized→enzymes→filtered→concentrated→extracted with ethanol and petroleum ether→filtered→concentrated→put on silica gel column→eluted→concentrated→got a dark-red viscous liquid.
Operating principles are:
1) add enzyme: add enzyme hydrolysis to make the cells and proteins, fats, sugars, etc. combined with the pigment free, so as to facilitate the extraction of solvents.
2)Extraction: The extract was extracted with 90% ethanol and petroleum ether (1:1) at room temperature with stirring overnight, and concentrated under reduced pressure after filtration.3)The elution conditions were found by thin-layer chromatography, and the best effect was achieved when the volume ratio of petroleum ether and edible 90% ethanol = 2:1.
4)The extracted concentrate was put on a silica gel column with a diameter of 10 cm and a height of 100 cm, and eluted with the eluent, and the red eluted portion was collected
5)The collected eluted portion was concentrated under reduced pressure.
The red viscous liquid obtained from the experiment was examined to have a moisture content of 0.37%, a fat content of 90.68%, a pigment:color scale E1%1cm(475nm)=143, and no capsaicin. He Wenzhi, Suo Quanling, etc. [5] also explored the column chromatography extraction and refining method of paprika red pigment: acetone was used as the extractant to extract the crude paprika red from the dried paprika, and the crude product was concentrated by reduced pressure distillation and processed for the column chromatography dehomogenization and refining operation. In view of the advantages of the column chromatography method, a large-size glass column was used for the column chromatographic separation, and silica gel with particle size of 74-152 μm was used as the packing material, and a mixture of petroleum ether and acetone (10:1) was used as the unfolding agent for the column chromatography. The crude product of paprika was eluted on the column, and the first liquid that came out was orange-yellow liquid (in small amount), followed by paprika pigment, and finally the yellowish liquid with strong spicy flavor, which was difficult to be eluted. The red pigment products were collected and concentrated by distillation under reduced pressure, and the color value was determined by 751 spectrophotometer with E1%1cm(460nm)=56.5, and the recovery of pigment could reach 67.2% on average.
In response to the problem that most of the existing literatures introduced the method of extracting non-spicy mixed pigments from red chili peppers without further separating and analyzing the mixed pigments, the separation of yellow pigments from chili peppers by column chromatography was proposed. The method used silica gel as stationary phase, acetone and 95% ethanol as eluent for the hot red pigment and hot yellow pigment respectively, and the amount of pigment separated each time was 4%~2% of the mass of silica gel, and the separated liquid was concentrated by distillation under reduced pressure. Through this process, not only can we get the main by-products of chili pigment---yellow pigment, but also improve the purity of the main components accordingly, and get the red pigment with high purity.
Adopting column chromatography separation technology, adsorbent X and mixed eluent were used for the pilot test to further separate red, orange and yellow in the paprika pigment, which could improve the color value and hue of the low-quality paprika red pigment greatly. Wu Mingguang et al. used column chromatography separation technology to separate the free crystalline capsicum red pigment monomer from the peel of chili peppers, and its content was greater than 95%, which was a breakthrough in the dosage form of capsicum red pigment in China.
1.3 Supercritical CO2 fluid extraction technology
Because of the oily properties of capsaicin, the use of organic solvents extraction and separation of capsaicin products have a high solvent residue, take the general eluent method of the product is difficult to meet the latest standards set by the Food and Agriculture Organization of the United Nations and the World Health Organization (FAO/WHO, 1984), which greatly affect the practicality and export of capsaicin. It is difficult for the products to meet the latest standards set by the Food and Agriculture Organization of the United Nations and the World Health Organization (FAO/WHO, 1984), which greatly affects the practicality and export of pepper pigment. Supercritical fluid extraction is a new chemical separation technology. The key to this technology is to understand the solubility of supercritical fluids and the changing law with the influence of many factors. Supercritical CO2 fluid extraction (SCFE-CO2) is the use of higher than the critical temperature, critical pressure CO2 fluid as a solvent extraction process. Fluid in the vicinity of the critical point not only has a very high solubility of substances, but also the solubility of substances with the system pressure or temperature changes, so that by adjusting the pressure or temperature of the system can be convenient for selective extraction and separation of different substances. The supercritical separation technology has simple process, low energy consumption, non-toxic extraction solvent, easy to recover, and the obtained products have very high purity, and the residual solvent meets the requirements of FAO/WHO. Zhao Yaping et al. used a self-designed supercritical CO2 fluid extraction equipment for the extraction of chili pigment. The equipment is mainly composed of gas supply system, supercritical CO2 fluid generation system, extraction and separation system, and metering system, and all the components are localized. The experiments showed that the optimal extraction conditions were particle size <1.2mm, extraction pressure 15MPa, extraction temperature 50℃, flow rate 6m3/h. During the extraction process, the separation effect of capsaicinoids and capsaicinoids was judged according to the absorbance curves from 200 to 600nm measured by UV3000 UV-visible spectrophotometer. The absorbance was measured at 449 nm with the acetone solution of the pigment, and the obtained value was the color value of the pigment. As can be seen from Table 2, the quality indexes of the extracted capsaicinoids exceeded the national standard.
The supercritical extraction device made by NOVA (Switzerland) was used to separate and purify the chili pigment. The optimum process parameters to make the product meet the FAO/WHO residual solvent standard requirements (hexane content ≤ 25mg/kg) were: extraction pressure 18MPa, extraction temperature 25℃, extractant flow rate 2.0L/min, extraction time 3h. The color value of the product could reach 342 under the optimum process conditions. Han Yuqian et al. used supercritical CO2 fluid extraction technology to refine paprika pigments with color value of 100-180 and solvent residue of 30×10-6~150×10-6. The experimental results showed that when the extraction pressure was controlled below 20MPa, the color value and hue of paprika pigments were almost unaffected by the loss of color value, and the residue of the organic solvent could be reduced to 2.7×10-6, but the red pigment and the yellow pigment in the paprika pigments had not been completely separated. It was found that the use of co-solvents such as 1% ethanol or acetone in the supercritical CO2 fluid extraction of capsicum pigments or the increase of extraction pressure could improve the yield of capsicum pigments. At lower pressure, almost all capsaicinoids were β-carotene, while at higher pressure, a larger proportion of red carotenoids such as capsaicinoids, capsaicinoids, zeaxanthin, β-cryptoxanthin, etc., and a small amount of β-carotene were obtained. In the two-step extraction process, the separation of paprika oil and β-carotene in the first stage ensured the enrichment of paprika pigments in the second stage, and the ratio of paprika red and yellow pigments reached 1.8. The results of the study on the dehiscentization of paprika pigments in the self-developed multifunctional supercritical CO2 fluid extraction and fractionation device showed that: yellow and spicy components could be extracted under the pressure of less than 10.0 MPa, and the results showed that the red and spicy components could be extracted under the pressure of less than 10.0 MPa, and the red and spicy pigments could be obtained under the higher pressure of higher pressure. The results showed that the yellow and spicy components could be extracted under the pressure less than 10.0MPa, and the red pigment could be retained; when the pressure was greater than 12.0MPa, the red component could be extracted completely. Although the supercritical fluid extraction of natural pigments has many advantages, but due to the large one-time investment in supercritical equipment, it has not been widely used in this field in China.
1.4 Other
The use of two-step extraction separation of red pepper, that is, the first organic solvent leaching method from the dry tip of the pepper extract contains red pigment, capsaicin and tar flavor odor pepper extract, and then supercritical CO2 extraction method to remove the tar flavor odor and the red pigment and capsaicin separate, so as to get the red pigment and capsaicin free of organic solvents, the yield of more than pure! The yields of red pigment and capsaicin without organic solvent were 5-7 times higher than those of the supercritical extraction method alone, and the quality far exceeded the standard of FAO/WHO (1984). Yao Zufeng and Jiang Hongjie carried out 54 experiments with six separation and extraction methods, through which they learned that the yield and quality of red pigment of chili peppers were closely related to the production technology and process conditions. Through the comparative analysis, we can compare the advanced and practicality of these six production techniques, the basic situation of the six processes are shown in Table 3.
From Table 4, we can see that: among the six production techniques, the quality of paprika red pigment produced by Technology Ⅰ is the best; the indicators of paprika red pigment produced by Technology Ⅱ and Ⅲ are in line with the standard, but the color value is lower; obviously, Technology Ⅳ, Ⅴ and Ⅵ can only extract the crude product with lower color value and lower purity, and need to be further developed to meet the requirements for the production of paprika red pigment. Crude, still need further refining.
2 Discussion
and prospects have formed a variety of chili pepper pigment separation and purification process, the conventional production method of organic solvent extraction, steam distillation, etc., but these methods can not be completely removed from the spicy taste, capsaicin is difficult to recycle, pigmentation rate is low, and the application of organic solvent extraction method tends to make the product of residual organic solvents, such as acetone, dichloromethane, acetone, Hexane, etc. exceeded the standard, narrowing the scope of application of the product. The use of supercritical CO2 fluid extraction technology can greatly improve the quality of chili pepper pigment products, high color value of the product, organic solvent residue is small, there is no thermal processing to ensure that the original composition of the natural substances are not destroyed, can be achieved at room temperature near the operation of the SCFE-CO2 technology to save energy, and can remove the odor of chili pepper products, but the operation of the method is more complex, and the equipment is expensive. The silica gel column chromatography method is easy to operate, the equipment conditions are not high, the separation effect is better, the removal of spicy flavor is complete, and it is suitable for small-scale development and production. According to the information provided, binary solvent extraction and separation of chili red pigment and chorizin technology has a very good extraction and refining effect. Foreign new research shows that, under milder conditions, subcritical propane in carotenoid extraction is better than supercritical CO2. ultraviolet-visible spectroscopy, thin-layer chromatography, gas chromatography, high-performance liquid chromatography and other analytical separation techniques have also been used to guide the selection of red chili pepper production process parameters.
Domestic deep development of chili pepper pigment products is still a big gap, slow technological progress, organic solvent extraction and separation as the main means, due to the limitations of the solvent method itself, the product quality is difficult to improve, reducing the economic value of the product. Therefore, the deep processing research of chili pigment products has a high value and broad prospects. It is important to avoid or reduce the loss of pigment components in primary processing and storage. Improvement of light resistance, antioxidant properties and applicability of chili pigments, the hope that fat-soluble pigments into water-soluble pigments, the development of preparation technology and emulsification technology, the development of these pigment preparations and processing technology in line with the development of the field of development and market development needs. Single-component supercritical solvent extraction has certain limitations, such as some substances in the extractant solubility is very low, or selectivity is not high, resulting in poor separation. The application of appropriate co-solvents (or entraining agents) can strongly affect the solubility, selectivity and P-V-T properties of supercritical fluids. Therefore, the development of appropriate co-solvents in the supercritical fluid extraction of paprika pigments can achieve more effective separation. Improving the deodorization technology along with the dehydrogenation technology will be conducive to the wider application of paprika pigments. Based on the research results of the existing chili pigment refining process, it is of great significance to research and develop chili pigment extraction technology with small investment, simple operation and high product quality.
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Capsaicin
Capsaicin is one kind of carotenoids, and it is also a popular antioxidant.
Capsicum is a genus of chili peppers in the family of Solanaceae, annual or perennial herbs capable of bearing spicy berries, and is also known by the aliases of paprika, sea pepper, Qin Pepper, spicy eggplant, bell pepper, vegetable pepper, and sharp pepper. Each 100g of fresh chili pepper contains 70-93g of water, starch 4.2g, protein 1.2-2.0g, vitamin C73-342mg; dried chili pepper mainly contains vitamin A. Chili pepper's spicy flavor is capsaicin (C16H27no3), capsaicin is mainly distributed in the placenta around the diaphragm and skin surface cells.
The original growth of chili peppers in the tropical regions of Central and South America, introduced to Europe in 1493, 1583-1598 years into Japan, introduced to China did not see the specific time, the earliest records of China on chili pepper see the Ming dynasty Gao Lian compiled "Zunsheng eight notes" (1591), there are: "pepper clusters, white flowers, the fruit is like a bald pen head, spicy taste and color. Bald pen head, taste spicy color red, very impressive" description. Chili pepper into China has two paths, one is the statement of the Silk Road, from West Asia into Gansu, Shaanxi and other places, the rate is far in the northwest cultivation; one is through the Strait of Malacca into South China, in the south of Yunnan, Guangxi and Guangdong and other places of cultivation.
It is said that the earliest chili peppers grew in the jungles of Chile, domesticated and cultivated in Mexico by collection to become a vegetable, and then imported into countries around the world. Nowadays, there are traditional chili eating contests in Chile. However, botanists in the last world of the 70's expedition, from the Yunnan Xishuangbanna's primitive forests found in the wild type of millet pepper, caused by the science and plant community widespread concern. This will likely trigger a chili pepper exotic and locally generated debate, if the continental plate drift said to discuss, the Pacific East Coast and the West Coast was originally a whole, South China, but also with the Central America is close to it.
Medical effects of chili pepper
First, chili pepper can burn fat
Chili pepper contains capsaicin, accelerate fat metabolism, promote the consumption of energy, thereby preventing the accumulation of body fat. For people who are not good at spicy people, the use of chili pepper to lose weight can not be too anxious, regular eating, so that gastrointestinal irritation slowly adapt.
Recently, Japan has a new interpretation of chili peppers. In Japan, it is believed that chili peppers are, in a way, a "tonic" for women, not a "natural enemy".
Because they believe that, in addition to sterilization, which contains a substance called "capsaicin", can promote hormone secretion, thereby accelerating the metabolism to achieve the effect of burning body fat, thus playing a role in weight loss.
And chili pepper ingredients are natural and reliable, in addition, they also believe that in some areas where spicy food is the mainstay, local women not only have fewer problems with acne, but their skin is more slippery.
Second, chili pepper can help face
Capsaicin in chili peppers, can be strong new blood, expanding the blood vessels of the facial skin, improve blood circulation in the face, so that the face is red. The premise is to stop, careful face acne outbreak.
Chili pepper can promote blood circulation will be coated with capsaicin on the skin, will expand microvascular, promote circulation, and make the skin red, hot. Currently there are manufacturers to use these principles, capsaicin into the socks, become "pepper socks", for winter warmth.
Chili pepper can reduce the discomfort of cold and flu for thousands of years, spicy food is often thought to sweat expectorant, and now found that seems to be the case. Spicy foods can dilute mucus secretion and help phlegm be coughed up so it doesn't obstruct the airways. University of California professor Irving Chipman even said, "Many of the cold and cough remedies sold over the counter are exactly the same as cayenne pepper, but I think it's better to eat cayenne pepper because it has no side effects at all."
Third, chili peppers can relieve pain
Capsaicin in chili peppers can reduce the P substance in nerve cells, so that the transmission of pain signals become insensitive. Cayenne pepper can also be used to treat rheumatism.
Cayenne pepper has often been used to relieve pain since ancient times, and scientists have only recently learned that capsaicin depletes the nerve transducing substances that send messages of pain to the nervous system. Through the pain-relieving principle of capsaicin, capsaicin cream has been used to relieve pain such as shingles and trigeminal neuralgia.
In red and yellow chili peppers, bell peppers, there is another component is capsanthin. And capsanthin is a type of carotenoid and a popular antioxidant these days. Raw peppers contain more vitamin C than oranges or lemons, and a single fresh red pepper provides almost half of the daily requirement of vitamin A recommended by nutrition experts. An ointment containing capsaicin is effective in reducing the pain of shingles.
Fourth, chili peppers can prevent cancer
According to research, chili peppers in the carotenoids can not only help vision, but also has the role of anti-cell mutation.
Capsaicin to prevent cancer from epidemiological studies, many spicy ethnic groups, such as Southeast Asia, India and other countries have less chance of developing cancer than Western countries. Scientists speculate that there are many antioxidant substances in these spicy foods, and that oxidation and chronic disease, cancer, and aging are inherently and directly related.
A recent study at the University of Hawaii pointed out that carotenoids in vegetables such as chili peppers and carrots stimulate the genes that send messages between cells (because when an organ is cancerous, the system for exchanging messages between cells malfunctions), which may have an important role in cancer prevention.
Preventing atherosclerosisOne red pepper contains one day's supply of beta-carotene, a powerful antioxidant that inhibits the oxidation of low-density cholesterol (LDL) into harmful forms.LDL, once oxidized, turns into a bad substance that clogs the arteries, just like butter that hasn't been put in the refrigerator. In other words, it is beta-carotene that intervenes at the initial stage of atherosclerosis.
Who should not eat more peppers?
Nowadays, dishes containing chili peppers are becoming more and more popular in the home. However, from a health care point of view, chili peppers are not suitable for everyone.
People suffering from fever, ulcer disease, chronic gastrointestinal disease, hemorrhoids, dermatitis, tuberculosis, chronic bronchitis and hypertension should not eat a lot of chili.
Thin people should not eat more chili. From the Chinese medicine point of view, thin people belong to the Yin deficiency and hot body, the so-called "thin people more fire" that refers to the heart. This type of person often manifested as dry throat, bitter mouth, eye congestion, head and feet, irritability, if you eat more chili pepper will not only make the above symptoms aggravate, but also easy to lead to bleeding, allergies and inflammation, severe canker sores and infections.
The hyperthyroid patients should not eat chili. Patients with hyperthyroidism are often in a state of high excitement, so it is not advisable to eat chili peppers and other strong stimulating foods.
Patients with nephritis should not eat chili peppers. Research has proved that in the human metabolic process, its spicy ingredients often have to be excreted through the kidneys, which has a different degree of stimulation of the renal parenchymal cells.
Here are capsaicin properties identified /khdt/khdt/200702/11153.html