Citricacid production

Citric acid Production - Dr. S. Sivasankara Narayani

1. Y5E02 BIOPROCESS TECHNOLOGY – Unit IV Citric acid Prduction D r . S. Sivasankara Narayani Assistant Professor Department of microbiology Ayya Nadar Janaki Ammal College sivakasi 27/08/20 Dr.SS

2. Intro Citric acid (2-hydroxy-1,2,3- propane tri carboxylic acid) is the most important commercial product, which is found in almost all plant & animal tissues. Citric acid is the most important organic acid produced in tonnage and is extensively used in food and pharmaceutical industries. Citric acid is a weak organic acid found in citrus fruits(lemon). It is good ,natural preservative and is also used to add an acidic taste to food and soft drinks. More than million tonnes are produced every year by fermentation 27/08/20 Dr.SS

3. History The discovery of citric acid has been credited to the 8th century Muslim alchemist Jabir Ibn Hayyan (Geber). Citric acid was first isolated in 1784 by the Swedish chemist carl Wilhelm Scheele, who crystallize it from lemon juice. Industrial scale citric acid production began in 1890 based on the Italian citrus fruit industry. In 1893, C. Wehmer discovered penicillin mold could produce citric acid from sugar. However, microbial production of citric acid did not become industrially important until world war I disrupted Italian citrus exports. 27/08/20 Dr.SS

4. PRODUCTION TECHNIQUES AND RAW MATERIALS Classified raw materials used for citric acid production in to two groups: with a low ash content from which the cations could be removed by standard procedures (e.g. cane or beet sugar, dextrose syrups and crystallized dextrose); (ii) raw materials with a high ash content and high amounts of other non sugar substances (e.g. cane and beet molasses, crude unfiltered starch hydro-lysates). Several attempts have been made to produce citric acid using molasses, which is preferred due its low cost and high sugar content (40-55%). The composition of molasses depends on various factors, e.g. the kind of beet and cane, methods of cultivation of crops and fertilizers and pesticides applied during cultivation, conditions of storage and handling (e.g. transport, temperature variations), production procedures, etc.. beet molasses is preferred due to its lower content of trace metals. Generally, cane molasses contains calcium magnesium, manganese, iron and zinc, which have a retarding effect on the synthesis of citric acid. 27/08/20 Dr.SS

5. FERMENTATION TYPES surface fermentation submerged fermentation solid state fermentation 27/08/20 Dr.SS

6. Note Surface Fermentation In the surface techniques, the microorganisms are cultivated on the surface of a liquid or solid substrate. These techniques are very complicated and rarely used in industry.  A. niger   forms a mycelium layer on the liquid surface of the aluminum or stainless steel trays 27/08/20 Dr.SS

7. Note Submerged fermentation  is a method of manufacturing biomolecules in which enzymes and other reactive compounds are submerged in a liquid such as alcohol, oil or a nutrient broth. Submerged Fermentation ( SmF )/Liquid Fermentation (LF) SmF utilizes free-flowing liquid substrates, such as molasses and broths 27/08/20 Dr.SS

8. Note Solid-State Fermentation (SSF)  involves the growth of microorganisms on moist solid particles , in situations in which the spaces between the particles contain a continuous gas phase and a minimum of visible water. Although droplets of water may be present between the particles, and there may be thin films of water at the particle surface, the inter-particle water phase is discontinuous and most of the inter- particle space is filled by the gas phase. The majority of the water in the system is absorbed within the moist solid-particles the more general term “solid-substrate fermentation” is used to denote any type of fermentation process that involves solids, including suspensions of solid particles in a continuous liquid phase and even trickling filters 27/08/20 Dr.SS

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14. Factors affecting citric acid Production  Nitrogen source  pH  Aeration  Trace elements  Temperature 27/08/20 Dr.SS

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17. Clarification 27/08/20 Dr.SS [email protected] [email protected]

18. Questions to think What are the steps involved in the citric acid production ? What is submerged fermentation ? What is solid state fermentation? Role of calcium oxide ? Pointout the use of citric acid What is surface fermentation? Organisms involved in the citric acid production Term refer to the study of oenology 27/08/20 Dr.SS

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