1. Methionine
DL-Methionine, CAS No.: 59-51-8, Molecular Formula: C5H11O2NS, Molecular Weight: 149.21.
Solid DL-Methionine is a white flaky crystal or crystalline powder. It has a special odor and a slightly sweet taste. It is spinny, melting point 280~281℃ (decomposition), soluble in water (3.3g/100ml, 25℃), PH value of 10% aqueous solution 5.6~6.1, stable to heat and air, unstable to strong acid. Soluble in dilute acid and dilute alkali, extremely insoluble in ethanol, and almost insoluble in ether. It can lead to demethylation.
2. Classification of methionine
The molecular structure of methionine is divided into two relative conformations, L-form and D-form.
Generally speaking, only the L-configuration methionine is biologically active and can be directly used by humans and animals. However, D-type methionine can be automatically converted into biologically active L-configuration molecules in the body, and from the perspective of nutritional value, D-type and L-type are almost identical. In addition, methionine hydroxyl analogs (liquid methionine) can be converted into biologically active L-type methionine by in vivo transformation, and they are also excellent sources of methionine for livestock.
3. Methionine applications
1. Used as a feed fortification agent. The deficiency of methionine in livestock and poultry will cause stunting, weight loss, weakened liver and kidney function, muscle atrophy, and fur deterioration. Adding 1kg of methionine to feed is equivalent to the nutritional value of 50kg of fish meal. The general amount added to feed is 0,05%-0.2%. 2.
2. Nutritional supplements. It has the same physiological effect as L-type methionine, but the price is low (L-type is made from DL-type), so DL-methionine is generally used.
3. It is suitable for the prevention and treatment of liver diseases and poisoning such as arsenic or benzene, etc. It can also be used for the treatment of dysentery and malnutrition caused by protein deficiency after chronic infectious diseases.
4. Functions of methionine
1. One of the essential amino acids, deficiency of which can cause liver and kidney disorders. It is especially important for the protection of liver function. It can promote the growth of hair and nails, and has the functions of detoxification and enhancing muscle activity. 2.
2. Sea urchin flavor is related to methionine and can be formulated as a flavoring agent.
5. Production methods of methionine
The process of methionine generation is mainly divided into the chemical synthesis method (acrolein method) and microbial fermentation method, etc.
The microbial fermentation method refers to the production of natural methionine through complex metabolic activities by using the life activity process of microorganisms to produce a simple carbon and nitrogen source. The microbial fermentation method has the advantages of mild reaction conditions and environmental friendliness, but its yield is low and the cost is relatively high, and only CJ CheilJedang uses the fermentation method to produce methionine.
The chemical synthesis method used in industrial production – generally starts from acrolein, accesses methylthio groups, produces carboxyl and amino groups, and finally transforms into methionine products. Depending on the reaction intermediates, the chemical synthesis method can be divided into the Hain method and the cyanohydrin method. Both of them use acrolein and methyl mercaptan as starting materials to produce methylthiopropionaldehyde. For the Hain method, methylthiopropionaldehyde is first prepared as a Hain derivative and then hydrolyzed to obtain solid methionine. The haine-based process has mature technology, high reaction yields, and high automation. By-products such as sodium sulfate, carbon dioxide, and ammonia can be recycled in the process, and Evonik, CHINA UNIS CHEMICAL, and Adisseo (part of the process) use this route.
From a comprehensive point of view, both the cyanohydrin method and the Hain method involve raw materials that are most highly toxic and volatile, and have high requirements for production equipment and management, further raising the barriers to entry in the industry.
6. Manufacturers of methionine
6.1 Evonik Industries AG
In addition to plants in Singapore, Belgium, and Germany, Evonik produces essential amino acids at a plant in Mobile, Alabama, USA, which has the largest capacity.
6.2 Bluestar Adisseo Company
Bluestar Adisseo Company has methionine production bases in France, Spain, and Nanjing, China. In 2014, the first integrated liquid methionine plant in China was fully commissioned, marking the completion of the first phase of 70,000 tons of liquid methionine at Adisseo’s Nanjing base, filling the gap in liquid methionine production in China. Adisseo is the world’s largest liquid methionine producer and one of the few companies in the world with the production capacity of both liquid methionine and solid methionine.
6.3 Zhejiang NHU Co., Ltd
In 2017, the first phase of Zhejiang NHU Co., Ltd‘s methionine production capacity of 50,000 tons began to enter the market, adding another Chinese force to the methionine industry. At present, the total methionine capacity is 300,000 tons.
6.4 Novus International, Inc
In 1991, Novus International, Inc was formally established. Although there were only two products for poultry applications at the beginning, since its establishment, Novus International, Inc has been carrying the great vision of “helping people to obtain healthy, safe and economical food and improve the quality of life”.
6.5 Sumitomo Chemical Co., Ltd
Sumitomo Chemical Co., Ltd. announced on October 3, 2019, that it has several methionine manufacturing plants at its Ehime plant in Niigata, Japan, which is the company’s only methionine manufacturing site in Japan. In October 2018, the company built a new 100,000 tons/year amino acid production line, bringing the total capacity to 250,000 tons/year
6.6 CHINA UNIS CHEMICAL by Share Ltd
In 2010, CHINA UNIS CHEMICAL by Share Ltd(CUC)’s 10,000 tons/year methionine project was put into operation, marking the beginning of China’s enterprises breaking the situation of complete dependence on imports of methionine. It has changed the industry pattern at home and abroad and made a great contribution to the development of the cyanide and feed additives industry in China.
6.7 CJ CheilJedang
In 2014, Malaysia’s L-methionine production plant was completed, which is the world’s first global-scale methionine plant with integrated methionine, which allows CJ CheilJedang to provide the best quality products around the world and in the first place.
6.8 Sichuan Hebang Biotechnology Co., Ltd
Sichuan Hebang Biotechnology Co., Ltd. (stock code: 603077) was established in 2002 and is located in Leshan City, Sichuan Province. The company’s 70,000 tons/year liquid methionine project has reached production capacity and standards.
