Natural pigments are not only attractive color, taste sweet pure dyeing good, non-toxic and harmless, and rich in nutrients needed by the human body, some also have a health care role. And synthetic coloring due to safety issues, the use of which has been gradually controlled. Therefore, to find and develop more natural pigments has become the development of food coloring in China's top priority.
Chili pepper is a kind of widely when the prevalence of vegetables, bright red color, thick and juicy meat. Easy to grow, pepper red pigment is a good security, and has a certain nutritional value of the first and pharmacological effects of natural food coloring.
Pepper red pigment is based on chili peppers as raw materials, the use of hexane or subcritical butane extracted from the high carotenoid orange-red natural food coloring. This pigment belongs to terpene pigment, the product is in the form of viscous liquid, or can be dried to powder. It is insoluble in water and has good thermal stability, acid and alkali resistance, light resistance and emulsification and dispersion. The solution of capsicum pigment can show deep red, orange red, yellow, light yellow and other colors depending on the concentration. And because it contains carotene, β-carotene and a variety of vitamins, itself has a rich nutritional value, therefore, chili pepper pigment can be widely used in food, medicine and cosmetics and other industrial products coloring, its main coloring components for chili red and chili pepper red and red, is a carotenoid, accounting for 50%-60% of the total amount of carotenoids. In addition, it also contains a certain amount of non-color components capsaicin. Chili red pigment color is bright, high color value, strong coloring power, good color preservation effect, can effectively extend the shelf life of food.
Capsaicin is extracted earlier by oil soluble method and solvent method. Oil soluble method, that is, with animal and vegetable oils (such as fish oil, cottonseed oil, soybean oil, vegetable oil, coconut oil, corn oil, etc.) soaked chili pepper skin or chili powder, and then separated out the pigment dissolved in the oil, the disadvantage of this method is that it is difficult to separate the oil and pigment, and it is difficult to get a thick pigment. Hexane extraction and a new extraction method developed in recent years - subcritical butane low-temperature extraction method, can be very good chili red pigment extraction, and has the advantages of large scale, low production cost, high color price. The difference between the two extraction processes lies in the comprehensive utilization of meal residue after extraction. After the extraction of n-alkane meal residue because of the high temperature of more than 100 ℃ direct steam desolvation, so the meal residue becomes black, can only do fertilizer or feed. And subcritical low-temperature extraction of meal residue after the color of brownish-yellow, where the active substances and cellulose and other properties have not changed, in the food industry still has a high value of use, such as filler as chili sauce, as chili powder spiciness regulator and so on.
Subcritical low-temperature extraction of chili red pigment process is divided into three processes: pretreatment, subcritical extraction, dehotterization.
1. Pre-treatment process
Chili pepper → cleanup → drying, deseeding → crushing → granulation → go to the extraction process
Cleaning: the acquisition of dried chili pepper generally contains a certain amount of impurities and a large number of chili stems, first remove impurities and chili stems. Drying, deseeding: drying facilitates deseeding, deseeding can improve the content of unit pigment.
Crushing: crushing can effectively destroy the organizational structure and physical form of chili, improve the surface area of the material, extraction is conducive to the diffusion of pigment molecules into the solvent. The particle size of the crushed material is generally 40 to 60 mesh.
Pelletizing: Chili powder is passed through the ring die pellet machine, resulting in Φ4x8 rod-shaped pellets.
2. Subcritical butane extraction process
Countercurrent extraction is carried out for 5 times on the raw material of chili peppers for granulation, with material solubility ratio of 1:1.3 and extraction temperature of 30-35℃, and the extract is obtained in the form of deep red paste. After low temperature desolvation meal can be further processed food products.
3. Spice removal
Paste extract is the total fat-soluble components of chili peppers, mainly containing chili red pigment and capsaicinoids, which restricts the application of chili red as a pigment, so there is a need to remove chili red pigment in the spicy substances. Currently, the dehotting of paprika red pigment is mainly a liquid-liquid extraction method. The use of 76% (v/v) of ethanol as a dehotting solvent and chili oil paste mixed thoroughly, so that capsaicinoids dissolved in the ethanol phase, and then use the capsaicinoid phase and the density difference between the ethanol phase centrifugal separation, the oil paste by a number of ethanol extraction, capsaicinoid-rich ethanol phase concentration recovery of ethanol, to get capsaicinoids, remove capsaicinoids after the oleoresin that is capsaicinoid red pigment. The main indicators of paprika red pigment are: residual solubility in paprika red pigment ≤ 20, paprika red pigment containing water shall not be detected ≤ 3%, the yield of paprika red pigment ≥ 9 ≥ 95%, the color value (460nm) ≥ 170~180. out of the acetone insoluble matter ≤ 3.
