Vanillin Overview

Vanillin is the first flavor synthesized by mankind, and was successfully synthesized by Dr. M. Hallman and Dr. G. Thiemann of Germany in 1874. It is usually divided into methyl vanillin and ethyl vanillin.

(1) Methyl vanillin: white or yellowish crystals, with the aroma of vanilla and rich milky flavor, the largest variety in the spice industry, is the main ingredient of the popular creamy vanilla flavor. Its use is very wide, such as in the food, cosmetic, tobacco industry as incense raw materials, corrective agent or fixed aroma agent, of which beverages, confectionery, pastries, cookies, bread and fried foods and other food products with the majority of the dosage. There is no relevant report that vanillin is harmful to human body.

(2) Ethyl vanillin: white to slightly yellow needle-like crystals or crystalline powder, similar to the aroma of vanilla beans, the aroma is stronger than methyl vanillin. It is a broad-spectrum spice, one of the most important synthetic spices in the world today, and an important and indispensable raw material in the food additives industry. Its aroma is 3-4 times that of vanillin, and it has a strong aroma of vanilla bean, and its fragrance lasts for a long time. It is widely used in food, chocolate, ice-cream, beverage and daily use cosmetics to enhance and fix the role of flavor. In addition, ethyl vanillin can also be used as additives for feed, brightening agent in electroplating industry, and intermediates in pharmaceutical industry.

Important flavorings

Vanillin is commonly known as vanilla powder, vanillin, vanilla powder, vanilla extract, vanillin, from the Brassicaceae plant vanilla beans in the extraction of an important spice, is one of the largest production of synthetic spices, is the deployment of chocolate, ice cream, chewing gum, pastries and tobacco flavoring of important raw materials. It occurs naturally in vanilla pods, as well as in clove oil, oakmoss oil, Peruvian balsam, tulip balsam, and benzoin balsam.

Vanillin has a strong and unique vanilla bean aroma, stable aroma, not volatile at higher temperatures. It is easy to be affected by light, oxidized gradually in the air, and easy to change color when meet alkali or alkaline substances. Aqueous solution reacts with ferric chloride to produce a blue-violet solution. It can be used in many daily chemical flavor formulas, but mainly used in edible flavors. Especially it is widely used in candy, chocolate, beverage, ice cream, alcohol, and also very useful in cigarette flavors.IFRA has no restriction regulations. However, care should be taken when using it in white flavored products as it is prone to cause discoloration.

Vanillin is also an important edible spice, as a foundation spice, used in almost all fragrance, a large number of food industry, as a food flavor widely used in bread, cream, ice cream, brandy wine, etc., in the pastry, cookies, the amount of additives in the 0.01 ~ 0.04%, candy for 0.02 ~ 0.08%. It is one of the most used spices in baked goods and can be used in chocolate, cookies, cakes, puddings and ice cream. Dissolve in warm water before use for better results. The maximum use level is 220mg/kg for baked goods and 970mg/kg for chocolate.

It is widely used in cosmetic flavors as a fixative, harmonizer and modifier. It is also an important flavor enhancer for beverage and food. It is also used in the manufacture of pharmaceutical L-dopa and methyldopa. It can also be used as nickel, chromium metal plating brightener.

Reference quality standard of vanillin used in flavor and fragrance

Physical and Chemical Properties

Vanillin has a strong and unique vanilla bean aroma, naturally occurring in vanilla pods, as well as in clove oil, oakmoss oil, Peru balsam, Tulu balsam and benzoin. By the sulfite coniferous wood pulp red liquid or lignin sulfonate in alkaline conditions, the high-pressure oxidation hydrolysis precipitated by white to light yellow crystalline powder or needle-like crystals.

Those precipitated from petroleum ether can also produce tetragonal crystal system crystals, aromatic gas, slightly sweet, gradually oxidized in the air, light decomposition, alkali discoloration, relative molecular mass of 152.15, relative density of 1.056. Melting point varies according to the crystalline form, the tetragonal crystal system of 81-83 ℃, needle crystals 77-79 ℃, boiling point of 285 ℃ (in the carbon dioxide gas), 170 ℃ (2.00 × 10e3Pa), boiling point of 2.00 × 10e3Pa. 10e3Pa), 162℃(1.33×10e3Pa), 146℃(0.533×10e3Pa), sublimation without decomposition, flash point 162℃, slightly soluble in cold water, soluble in hot water, soluble in ethanol, ether, acetone, benzene, chloroform, carbon disulfide, glacial acetic acid, pyridine and volatile oil. Aqueous solution reacts with ferric chloride to produce a blue-purple solution. Rat oral LD(50) 1580mg/kg, rat percutaneous LD(50) 1500mg/kg.

The industrial production method is that eugenol generates isoeugenol in the presence of potassium hydroxide, and then reacts with acetic anhydride to generate isoeugenol acetate, which is then produced by oxidation and hydrolysis. It is an important raw material for chocolate, ice cream, chewing gum, pastry and tobacco flavor. It can also be used as a harmonizer and perfume fixer for cosmetic fragrances. It is also the raw material of pharmaceutical industry.

In recent years in the vanillin commodity appeared a new fashion. Clove oil or clove basil oil extracted eugenol as raw material, by isomerization and oxidation of the vanillin obtained, because it can be regarded as a natural equivalent, so it is known as the natural level of vanillin and enter the spice market, the price is about 5 times as much as the synthetic products.

Functions and Uses

(1) Edible flavoring: vanillin is an edible flavoring agent, with the aroma of vanilla bean and strong milky flavor, it is an indispensable and important raw material in the food additive industry, and is widely used in a variety of flavoring foods that need to increase the milky flavor, such as cakes, cold drinks, chocolate, candies, cookies, instant noodles, breads, and tobacco, flavored liquors, toothpaste, soaps, perfumes and cosmetics, ice creams, beverages, as well as daily-use cosmetics to increase the flavor and fix the aroma. It can be used in cosmetics to increase and fix the fragrance. It can also be used in soap, toothpaste, perfume, rubber, plastic and pharmaceuticals. It meets the FCCIV standard.

(2) Domestic vanillin is mainly used in food additives. In recent years, the application in the field of medicine has been broadening, and it has become the most potential field of vanillin application. At present, the domestic consumption of vanillin: food industry accounts for 55%, pharmaceutical intermediates account for 30%, feed flavoring agent accounts for 10%, cosmetics and so on accounts for 5%.

The application field of vanillin in foreign countries is very wide, a large number of pharmaceutical intermediates, also used in plant growth promoters, fungicides, lubricating oil defoamer, electroplating brightening agent, printed circuit board production of conductive agents and so on.

Preparation process of vanillin

(1)Concentrated Vanillin
Concentrated Vanillin has strong and long-lasting clove and vanilla aroma, and its aroma intensity is 16-25 times of vanillin. Concentrated vanillin was successfully developed as early as in the 1920s. The initial synthetic route is to use safrole as raw material, and the alcoholic solution of potassium hydroxide for hot pressure reaction to make it open the ring, and then use sodium ethyl sulfate to make the ring on the hydroxyl ethylated, and finally in the ethanol solution hydrolyzed with sulfuric acid will be obtained strongly fragrant vanillin. However, due to the lack of purity of the aroma of the products of this method, it is seldom used in practice.

In the 1950’s, a synthetic route was developed to produce vanillin from eugenol (U.S. Patent 2663741), which enabled the industrial production of vanillin, and in the 1960’s, the Soviet Union’s flavor chemists successfully developed a synthetic route using the cheaper and more readily available catechol as the raw material. First, catechol monoalkylation with allyl chloride, yield 75%; followed by rearrangement reaction, yield 35% to 38%; and then monoethylation with sodium ethyl sulfate, yield 82%; and finally isomerization with potassium hydroxide will be obtained thick Fu Fu vanillin, yield 84%, the crude product melting point after recrystallization of 85.5 ~ 86 ℃.

Concentrated vanillin can be used in food flavor formulations such as candy, beverage, ice cream, etc. FEMA No. 2922, it can also be used in cosmetic and daily flavor formulations such as soap. It can be used not only as a flavor, but also as a synergist and antioxidant. Flavorists in the former Soviet Union held a different view of the aromatic properties of strongly perfumed vanillin. They added it to chocolate and other food flavors and found that the product had no vanillin aroma, so they thought it could not be used as a vanillin substitute in food flavors. However, when used in soap scenting test, found with its soap samples with strong clove and vanilla aroma, but also with vanillin and isoeugenol is different from the strong forte vanillin on alkali, light, oxidation is very stable, soap samples by the storage of the color does not change. It is believed that vanillin is suitable to be used in daily chemical flavor formulations, especially suitable for fantasy-type flavors.

(2)Industrial production method of vanillin
The industrial production of vanillin has a history of more than 100 years, people have studied many synthetic ways and methods, but the following three methods are mainly applied to large-scale industrial production.

A. Lignin route. Take the lignin sulfonate contained in the sulfite pulp waste liquid of paper-making industry as raw material, hydrolyze it by alkaline high temperature and high pressure, then dehydrate it and then oxidize it. This method is mainly used in Canada and the United States to produce vanillin.

B. Guaiacol-formaldehyde route. Guaiacol is the most important raw material for the synthesis of vanillin, and the synthetic route with guaiacol, formaldehyde, and p-nitrosodimethylaniline as raw materials is also known as the nitrosyl method. This method is mainly used in countries such as the former Soviet Union and China.

C.Guaiacol-glyoxalate route . Guaiacol and glyoxalic acid are used as raw materials, and vanillin is made by condensation, oxidation and decarboxylation.

The method has been successfully researched and developed mainly by the French company Rhone-Poulenc and is being produced on a large scale. The used glyoxalic acid can be produced by ozonolysis of dimethyl maleate (German Patent 3224795). This synthetic route is considered to be the most suitable method at present because of the convenient source of raw materials, fewer reaction steps, lower cost and less pollution of three wastes.

Content analysis

Method 1: Analyzed by ultraviolet absorption spectrophotometry (see GT-29). Preparation of standard solution Accurately weigh about 100mg of the pharmaceutical reference standard vanillin, put it into a 250ml volumetric flask, and mix it with methanol. Take 2.0 ml of this solution and put into a 100 ml volumetric flask and mix with methanol. Preparation of specimen solution Accurately weigh the specimen about 100mg, the preparation method is the same as the preparation of the standard solution above. Operation take the above solutions were put into a 1cm quartz cell, in the maximum absorption wavelength of about 308nm to determine the absorbance. Calculate the content (X) of vanillin (C8H8O3) in the sample (mg) according to the following formula: X=12.5c(Au/As) in which c–concentration of vanillin in the standard solution, μg/ml; Au–absorbance of the sample solution; As –Au – absorbance of the sample solution; As – absorbance of the standard solution.
Method 2: Determination by gas chromatography (GT-10-4) with non-polar column method.

Toxicity and Use Limits

LD(50)orally in rats,guinea pigs:1580,1400mg/kg(Jenner)
Limit of use FEMA(mg/kg): soft drinks 63; cold drinks 95; confectionery 200; bakery products 220; puddings Chemicalbook 120; gummies 270; chocolates 970; laminating layers 150; margarine 0.20; sugar syrups 330～20,000. according to FAO/WHO: canned baby food and cereals used in convenience foods are allowed a maximum dosage of 70%. The maximum permitted level of food additives is 70mg/kg (1992).

Maximum Allowable Use Levels of Food Additives
Maximum Allowable Residue Standard

Industry Development Situation
According to “China Vanillin Market Development Research and Investment Value Report (2019 Edition)” released by Lignum Consulting, the annual consumption of vanillin in the global market is 16,000-20,000 tons, and the annual consumption of vanillin in China is 2,000-2,500 tons. The main domestic enterprises are Jiaxing Zhonghua Chemical, Liaoning Shixing Pharmaceutical and Chemical, Ningbo Wanglong, etc. The supply and demand are basically balanced.

There are two main problems for domestic enterprises. Firstly, domestic enterprises have relatively single products, insufficient integration of upstream and downstream industry chain, and certain shortcomings in technology. Secondly, Jiaxing Zhonghua and other enterprises are not located in the park, and the wastewater discharge of guaiacol is large, so there is some uncertainty about the business prospect.

In addition, the main products of Kunshan Aroma Natural Flavors are eugenol vanillin and ferulic acid vanillin etc., i.e. vanillin produced by using renewable substances such as eugenol and ferulic acid as raw materials, and the Company has become one of the major producers of such products in the world. The Company will sell a total of approximately 200 tons of the aforesaid products in 2019, accounting for approximately 30% of the global market share of similar products, with the main customers being Chihuateng, ABT of the United States and others.

Brother Technology plans to invest RMB1.26 billion to build a 20,000-ton phenylenediol and 31,100-ton phenylenediol derivatives production project in Isan Industrial Park, which will be implemented in two phases. In the first phase, the project will produce 10,000 tons of hydroquinone (including 6,000 tons of catechol and 4,000 tons of hydroquinone), 3,430 tons of guaiacol, 2,625 tons of ethyl guaiacol, 3,000 tons of vanillin, 2,500 tons of ethyl vanillin, 500 tons of resveratrol ether, 500 tons of p-phenylene di-anisole, and 2,000 tons of p-hydroxyanisole, etc. The project will be implemented in two phases.