Production process of edible natural coloring
(I) Extraction method
Commonly used method. Raw materials after sorting, washing, drying, crushing, extraction with solvents (such as water, ethanol), and then through the separation, concentration, refining and other processes to produce finished products
(B) tissue culture method
Cultivate and proliferate with plant tissue cells, cultivate a large number of pigmented cells in a short period of time, and then extract them with the usual methods. The production of pigment by tissue culture method is not limited by natural conditions.
(C) Crushing method
After washing the raw materials, impregnated with a weak alkaline osmotic solution containing 1% sodium bicarbonate and sodium chloride, to be completely adhered to the surface of the leaf with osmotic solution, freezing to rupture the cell membrane. Then thawed at room temperature, centrifugal dehydration, remove the cellular fluid, after drying to get the product.
(D) Microbial fermentation method
Commonly used red pigment is indica rice or glutinous rice by water immersion, steaming, plus red fermentation of Aspergillus oryzae.
(E) Enzyme treatment method
Japan now adopts enzyme treatment method to produce gardenia blue pigment, gardenia red pigment, gardenia green pigment, etc., the process is:
Gardenia fruit extract — matrix solution — soy protein — amino acid and its peptide — mixture — enzyme treatment — enzyme inactivation — filtration — separation — concentration — drying — finished product
Example: Erythrosine (Erythrosine)
Alias: Cherry Red, Edible Red No. 14
Edible Red No.3 (Japan)
2Na+-H2O
Characteristics:
Good resistance to heat (105°C), reduction and alkali. Poor salt, light and acid resistance (precipitation can occur in acidic solutions), easily soluble in water in cherry red color.
Toxicological basis:
① LD50: 6.8g/kg body weight in mice orally
②ADI: 0~0.1mg/kg
Precautions for use:
①Powder colorant should be pulped with a small amount of cold water first and then slowly added to boiling water under stirring.
② The water must be distilled and deionized water to avoid the presence of Ca2+ caused by the colorant precipitation
③Excessive exposure to sunlight will cause the coloring agent to fade, so avoid light
Scope of use: meat enema, compound seasoning, puffed food, fruit and vegetable juice drinks, carbonated beverages, prepared wine, etc.
Erythrosine Aluminum Lake
Alias: C.I. Edible Red 141 No.
Chemical Structure:
Aluminum precipitate of water-soluble food coloring agent Erythrosine spread on alumina hydrate
Properties:
Insoluble in water and organic solvents, superior to erythrosine in light, salt and heat resistance
Method of Preparation:
Erythrosine aqueous solution is added to the alumina hydrate formed by the action of AlCl3, Al2(SO4)3 aqueous solution and Na2CO3 to precipitate and adsorb, forming erythrosine aluminum chromophoric precipitates (other aluminum chromophoric precipitates are also made in the same way)
Example: Sodium Copper Chlorophyllin (SodiumCopper Chlorophyllin)
The structure of chlorophyll: higher plants chlorophyll has a, b two kinds, when the 3 position on the R for methyl for chlorophyll a; for aldehyde for chlorophyll b, usually a:b = 3:1. its molecular structure is as follows:
Chlorophyll Properties:
Chlorophyll a blue-black, melting point 117 ~ 120 ℃, ethanol solution is blue-black
Chlorophyll b dark green, melting point 120 ~ 130 ℃, ethanol solution is green or yellowish green
Translated with DeepL.com (free version)
Very unstable and sensitive to light and heat. Under acidic conditions, magnesium atoms in the molecule can be replaced by hydrogen atoms, generating dark green to greenish-brown demagnesium chlorophyll.
Green vegetables can be treated with lime water or Mg(OH)2 before processing to prevent the formation of demagnesium chlorophyll and maintain the fresh green color of vegetables. However, too much alkali is easy to damage the plant’s tissue and its flavor, vitamin C is also lost.
Under appropriate conditions, the magnesium atom in the chlorophyll molecule can be replaced by copper, iron and zinc, etc., among which the color of sodium copper chlorophyllate is the brightest, stable to light and heat, and is used as a coloring agent in the food industry.
Chlorophyll in the heating to reach its boiling point is easy to be oxidized to lose green, such as green vegetables in the processing of hot water at 60 ~ 75 ℃ before scalding, you can exclude the oxygen in the vegetable tissues to avoid high-temperature treatment of oxidative discoloration.
Example: Lycopene
Studies have found a correlation between low intake of lycopene and the development of certain cancers. Regular tomato eaters have a 45% less chance of developing prostate cancer than those who do not eat tomatoes regularly. Patients with cirrhosis of the liver, pancreatic cancer, gastrointestinal tract cancer, and bladder cancer all had lower levels of lycopene.
Carotenoids in lycopene has the strongest antioxidant capacity, is -carotene 2 times, VE 100 times, to prevent oxidative damage to cells, activate immune cells. Therefore, lycopene has good anti-cancer function and can inhibit the proliferation of cancer cells. However, lycopene cannot be synthesized in the body and can only be consumed through diet.
Lycopene is a carotenoid that was discovered and extracted as early as 1875, but because it is not a vitamin A original, it has not attracted attention for a long time. However, recent studies have shown that lycopene is not only a good natural pigment, but also has superior physiological functions.
Properties:
Fat-soluble pigment, soluble in ether, petroleum ether, hexane and acetone. It has good thermal stability and is resistant to ions such as K+, Na+, Mg2+, Fe2+, Al3+ and Zn2+, but not to ions such as Fe3+ and Cu2+. Hydrochloric acid has a destructive effect on lycopene, better alkali resistance, better redox resistance, but not resistant to light.
Method of Preparation:
Widely found in nature, mainly distributed in tomatoes, watermelon, red grapes and grapefruit and other fruits and red palm oil, of which the highest content in tomatoes, but tomato varieties and ripening varies.
The lycopene content in processing tomatoes is 3~3.5 times that of fresh edible tomatoes, and the higher the maturity, the higher the content of red tomatoes.
The lycopene content in Xinjiang tomato paste is generally above 400mg/100g. Production of tomato paste by-products (tomato skin and tomato seeds) are mostly discarded. Tomato skin is relatively rich in lycopene, generally about 20mg/100g.
There are several methods for the extraction of lycopene as follows:
(1) direct crushing method
(2) leaching method
(3)Enzyme reaction method:
(4) Supercritical CO2 extraction
Example: Corn yellow (CornYellow)
Alias: Corn yellow pigment
Chemical structure: Corn yellow pigment belongs to carotenoids, the main coloring components for zeaxanthin (zeaxanthin) and cryptoxanthin (cryptoxanthin)
Traits:
Temperature: blood red oily liquid above 10 ℃, with the increase of temperature, zeaxanthin degradation speed up. 40 ℃ below the more stable, high temperature on the zeaxanthin has a certain destructive effect, 100 ℃ 7h fading color
Solvent: soluble in ether, petroleum ether, esters and other non-polar solvents, can be phospholipids, monoglycerides and other emulsifiers emulsification.
pH and Mn+: little effect
Light and heat: sensitive. Direct irradiation of sunlight has obvious destructive effect, while indoor natural light has less effect on it. Therefore, foods colored with corn yellow should avoid direct sunlight as much as possible during storage and transportation in order to maintain the color of foods
Method:
Zeaxanthin is mainly found in the cuticular endosperm of corn. During the production of starch from corn, most of the zeaxanthin goes into the by-product, yellow slurry water or its precipitate (corn protein wet powder) or its dried product (corn protein powder). Therefore, the by-products of corn starch production are the raw materials for the production of zeaxanthin
①Conventional extraction process
②Supercritical propane extraction
Usage:
Zeaxanthin is a functional natural food coloring with strong physiological activity, which can be added to hydrogenated vegetable oils and candies. At present, the industrialization method of separating and purifying zeaxanthin should be studied to improve the quality of zeaxanthin products.
Example: Caramel
Alias: caramel color, sauce color
Classification: According to the different production methods can be divided into four categories:
When coloring a product with caramel, the charge of the caramel particles should be the same as that of the colloidal particles of the colored material. If the caramel is put into a colloidal solution with opposite charges, the different charges will attract each other to form large particles and precipitate. Since soft drinks usually contain negatively charged colloidal particles, negatively charged caramel colors should be used. Negatively charged caramels are often referred to as “acid-resistant” caramels.
Soft drinks are the largest user of caramel in the world. In the United States, 75% of all caramel products are used in the soft drink industry. It is generally used in cola beverages at a dosage of less than 4 g per 3 liters. Since it adds only 1 calorie per liter of beverage, it has become the coloring of choice in diet beverage processing. In carbonated beverages, the emulsifying effect of caramel prevents aromatics from separating out. The addition of caramel to cookies complements their color tone and improves their appearance.
02
Color Protectors
Definition: also known as coloring agent, coloring agent, is able to meat and meat products in the role of coloring substances, so that in the process of food processing, preservation and other processes will not be decomposed, destroyed, presenting a good color of non-pigmented substances.
I. Types and roles of coloring agents
Colorants: nitrate, nitrite
Role: color, antibacterial, flavor enhancement
Coloring auxiliaries: ascorbic acid, niacinamide
Second, color protection mechanism
During storage and processing, meat will gradually turn from bright red to dark red to brown. This is due to the fact that Fe2+ in myoglobin (Mb) and hemoglobin (Hb), which are the color-presenting substances of meat, are gradually oxidized to Fe3+, which become high iron myoglobin and high iron hemoglobin, and make the meat change color.
Role of NO2-:
The added NO2- acts with lactic acid in meat to generate HNO2, and the unstable HNO2 decomposes NO (nitric oxide) at room temperature, and NO reacts with Mb and Hb to generate MbNO (nitroso myoglobin) and HbNO (nitroso haemoglobin) respectively, which are very stable and not easy to be browned.
The role of NO3-:
Nitrate, on the other hand, needs to be reduced by bacteria in food processing to generate NO2- and then play a role
Coloring mechanism
MbNO releases sulfhydryl group (-SH) when it meets heat, and generates a more stable nitroso hemochromogen with bright red color.
Role of L-ascorbic acid:
L-ascorbic acid is used to prevent the oxidation of myoglobin and can reduce oxidized brown high iron myoglobin to red reduced myoglobin.
Role of nicotinamide:
Nicotinamide can be combined with myoglobin to generate a very stable nicotinamide myoglobin, difficult to be oxidized, so in the curing process of meat products to add the appropriate amount of nicotinamide, you can prevent myoglobin in the generation of nitrite from nitrite to the oxidative discoloration during the period of nitrite.
Third, the safety of coloring agents
Nitrite has a certain degree of toxicity, especially with amines to generate a strong carcinogen nitrosamines.
LD50 mg/kg: nitrate 3236 nitrite 220
So far, there are no alternatives with the same effect.
After weighing the advantages and disadvantages, all countries in the premise of ensuring safety and product quality, strict control of the use. At the same time, the use of color protection additives to reduce the generation of nitrosamines.
(A) NO2- toxicity
Formation of high iron Hb: NO2- can be combined with hemoglobin (Hb) to form high iron Hb, and make Hb lose oxygen-carrying function, can be asphyxiated. The lethal dose to human is 32mg/kg body weight.
Generation of nitrosamines: In protein metabolites there is the presence of secondary amines, in the gastrointestinal tract of animals and humans it can react with NO2- to generate nitrosamines.
There are many kinds of nitrosamines, most of which are strongly carcinogenic and toxic to animals and human beings, and can even be pathogenic to the next generation through the placenta or breast milk. In food add ascorbic acid, isoascorbic acid or vitamin E to prevent the generation of nitrosamines.
(ii) NO3- toxicity
NO3- can be in food, water or gastrointestinal tract, especially in the gastrointestinal tract of young children less than 6 months is reduced to NO2-.
Fourth, the use of sodium nitrite
Properties: white to light yellow crystalline powder, soluble in water, easy to absorb moisture. It can slowly absorb oxygen in the air and gradually oxidize to NaNO3.
This product and meat products in myoglobin (Mb), hemoglobin (Hb) in addition to the generation of bright, bright red nitroso-myoglobin (Mb-NO) and nitroso-hemoglobin (Hb-NO) and color protection, but also to produce a cured meat special flavor. In addition, this product has the effect of inhibiting bacteria and inhibiting the production of toxin on many kinds of anaerobic Clostridium difficile bacteria (such as Clostridium botulinum, Lactobacillus green, etc.).
Toxicological basis:
①LD50 Mouse oral 220mg/kg body weight
②ADI: 0~0.2mg/kg body weight.
Use:
①Not to be added to infant food
②Maximum use level of meat products: 0.15g/kg.
③Residue in terms of NaNO2: canned meat residues
(iii) Impregnation method. SO2 is used and passed into the liquid.
This type of bleach is mainly used for sugar products, canned vegetables (mushrooms, bamboo shoots), fruit wines, frozen rice and noodle products, dried fruits and vegetables (dried apricots, candied fruits, raisins) and so on.
Fourth, the use of sulfite precautions
① sulfites destroy thiamine, should not be used for fish food.
② metal ions can be oxidized sulfite, but also significantly contribute to the coloring agent has been faded oxidation color. Metal chelating agents can be used to remove these metal ions originally present in the food.
(iii) Sulphite-based solutions are unstable and are best prepared and used now. Pay attention to control the residual amount. Sulphites can be desulphurized by heating, stirring and vacuuming.
④Sulfite is harmful to the gel properties of pectin. When dealing with fruits, it is limited to making jam, dried fruit, dried fruit, fruit juice drink, fruit wine, etc. It can not be used as raw material for plastic canning. Moreover, if the raw material with large residue is used for canning, the can wall will corrode seriously, and harmful hydrogen sulfide will also be produced, which should be avoided.
