Pure vanillin chemical name is 4-hydroxy-3-methoxybenzaldehyde, also known as methylprotocatechualdehyde and vanillin. It is an important broad-spectrum high-end flavor, and is one of the largest spices in the world by 2019. It has a sweet bean flavor and powder flavor, and can be used as a fixing agent, coordinating agent and flavoring agent. It is widely used in food, beverage, cosmetics, daily chemicals, medicine and other industries. The proportion used in the downstream industry is about 50% for food additives, 20% for pharmaceutical intermediates, 20% for feed additives, and about 10% for other purposes.
Vanillin is one of the most widely used food flavor enhancers in the world at present, and has the reputation of "king of food flavor". It is mainly used as a flavor enhancer in the food industry, and is used in cakes, ice cream, soft drinks, chocolate, baked candy and alcohol. The addition amount in cakes and cookies is 0.01%~0.04%, 0.02%~0.08% in candy, the maximum use amount of baked food is 220mg · kg-1, and the maximum use amount of chocolate is 970mg · kg-1, It can also be used as a food preservative additive in various foods and condiments; In the cosmetics industry, it can be used as a flavoring agent in perfume and face cream; In the daily chemical industry, it can be used in daily chemical products to modify the fragrance; In the chemical industry, it is used as defoamer, vulcanizing agent and chemical precursor; It can also be used for analysis and detection, such as testing amino compounds and some acids; In the pharmaceutical industry, it is used as an agent to shield the odor. Because vanillin itself has antibacterial effect, it can be used as a pharmaceutical intermediate in the pharmaceutical industry, including in the treatment of skin diseases. Vanillin has certain antioxidant and cancer prevention effects, and can participate in signal transmission between bacterial cells. These potential application fields will promote the rapid growth of vanillin market demand in the future. By 2019, the annual consumption of vanillin in the global market will be about 20000 tons.
There are three main preparation methods of vanillin:
① It is directly extracted from natural plants such as vanilla beans, but the cost of this method is high and the yield is low.
② It is synthesized by chemical methods, using industrial pulp waste liquid and petroleum chemicals as raw materials, but the vanillin produced by chemical synthesis has a single flavor and is easy to cause environmental pollution, which is inconsistent with the consumption trend of natural raw materials in the downstream application market.
③ Vanillin was prepared from renewable resources eugenol and ferulic acid as natural raw materials.
Antimicrobial mechanism of vanillin:
The research on the antibacterial mechanism of vanillin mainly includes three aspects: acting on the cell membrane and destroying the integrity of the membrane; It acts on enzymes to inactivate essential enzymes; It acts on genetic material to inactivate genetic material or destroy its structure.
Destroy the integrity of cell membrane
The phenolic group in vanillin has hydrophobicity, and the lower the pH value, the stronger the hydrophobicity, which can make the cell membrane unstable, destroy the structure of the cell membrane, make the cell wall appear concave, the cell membrane protrudes inward, and the cytoplasm condenses and vacuoles form.
However, vanillin has different degrees of damage to different cells. The cell wall of gram-positive bacteria is thicker than that of gram-negative bacteria, and the degree of cross-linking is high, which can effectively prevent the entry of vanillin. The gram-negative bacteria have loose structure and contain more lipids, and vanillin is easy to combine with it. Therefore, the bacteriostatic effect on gram-negative bacteria is significantly stronger than that on gram-positive bacteria. This is also related to the shape of microorganisms. The surface area of bacilli is larger than that of cocci. Its unit area can combine with more vanillin, so vanillin has better bacteriostatic effect on bacilli than cocci. In addition to having different antibacterial activity to different microorganisms, the concentration of vanillin also affects the antibacterial activity. The higher the concentration and the longer the action time, the higher the antibacterial activity.
Deactivate essential enzymes
Organisms are composed of cells. Each cell displays various life activities due to the existence of enzymes, and the metabolism in the body can be carried out. Proteins, RNA or their complexes that catalyze specific chemical reactions are biocatalysts. The chemical nature of most enzymes is protein, and their activities are affected by some external conditions, such as pH, salt ion concentration, temperature, etc. Vanillin destroys the cell membrane and causes changes in the intracellular environment, indirectly inhibits the activity of enzymes and affects the metabolism of cells. For example, Vanillin will inhibit the activity of DNA polymerase.
Inactivate genetic material or destroy structure
The genetic material of most organisms (organisms with cell structure and DNA viruses) is DNA, which can guide the synthesis of proteins, thus controlling metabolism and biological characteristics. Vanillin can inhibit the synthesis and expression of genetic material during the microbial delay period, which may be due to the destruction of cell membrane, indirectly inhibiting the enzymes involved in the synthesis and expression of genetic material; Other studies have shown that vanillin can affect the expression of transporter mRNA in rat liver.
Safety of vanillin and problems in application:
Vanillin is a natural plant ingredient and is recognized as a safer food additive. Due to the small amount of vanillin added in food, no relevant report on the harm of vanillin to human body has been found by 2015. In China, there is no restriction on the addition of vanillin in other products, except that no vanillin can be detected in foods for infants aged 0-6 months.
The safety of vanillin is closely related to its use characteristics. Vanillin is a natural food additive with multiple functions and can play multiple roles at low doses. Vanillin can effectively reduce the levels of serum triglycerides and triglycerides combined with various lipoproteins in experimental mice after being ingested with daily diet, and the effective use of vanillin in reducing blood lipids is consistent with the use of vanillin as a small amount of food additive added in food. Some scholars have proposed that when mice take vanillin orally, the level of antioxidant active substances in the blood increases with the increase of vanillin concentration, indicating that the antioxidant activity of vanillin may play a greater role in daily health care. Therefore, vanillin can play multiple roles at low doses and is beneficial to health, which is the basis of its use safety.
However, the addition of vanillin may also have a bad effect on the preservation of fruits and vegetables, which is the main problem in the application of vanillin. It is reported that when pineapple coated with vanillin film is stored at 10 ℃, the VC content decreases rapidly and is lower than that of the control group. Although vanillin treatment can enhance the yellow color of pineapple, it increases the appearance attractiveness of the fruit and results in the loss of nutrients. In addition, because vanillin itself has a strong milk flavor and is unstable when exposed to heat, it will also affect the inherent aroma of food raw materials. In production, the amount of vanillin added should be strictly controlled according to the actual situation, and the production and processing technology and operation should be strictly standardized to avoid adverse effects on the sensory quality of food. For how to effectively avoid the problems caused by vanillin's own characteristics, it is also necessary to conduct in-depth research in its mechanism, processing technology and other aspects.