Optimization Of Fermentative Conditions For Producing Erythritol By Corn Starch Method

Erythritol (1,2,3,4-butanetetrol) is a four-carbon sugar alcohol with a molecular weight of122. Its appearance is white and crystal powder and its viscosity is low. Melting point is121℃, boiling point is329～331℃. It can absorb more energy when it is soluted in water, dissolution is-97.4J/g. It has a60%～70%sweetness relative to sucrose and with low energy value, only5～10%of sucrose(erythritol1.7kJ/g, sucrose16.7kJ/g), it is also the lowest energy value of all the sugar alcohol.Erythritol has a wide application in the field of food, medicines and chemical products. It does not involve in Maillard’s reaction and affect the sugar metabolic, so it is suitable for diabetes patients. Because mouth bacterium can not utilize it and it can not generate insolubility glucosan and lactic acid, so it can not induce saprodontia. Erythritol is with low hygroscopicity, fraicheur, good crystallinity and low energy value.so it is suitable chutty, candy and so on. In the medical profession, erythritol can be served as correctant and excipient for medicine. it can improve the taste of medicine effectively. It can replace sucrose to execute health products of low energy value, so it can satisfy the requirement of diabetic, adiposis, high blood pressure. In chemical industry, erythritol can be used as intermediate product in organic compound. It has wide application prospect in resin synthetic and paint, explosive production.At the moment, the chief production methods of erythritol are biological extraction, chemical compound, microorganism fermentation. Erythritol can be extracted from moss and some fruits. But it needs more native material, and with low production efficiency, so it has not be spread. Under high temperature, starch can be reductive into erythritol with accelerant nickel. Because the efficiency of chemical compound method is very low, it has not be applied in industry. High starch farm products like corn can be decomposed into glucose by amylase. then fermented it by Candida mycoderma, erythritol can be obtained after concentration, crystallization, drying and separation. Compared with chemical compound, its procedure is moderate and easily control, it can be produced in industry. So now the most universal method is microorganism fermentation.For a long time, because the native material is very expensive, the production of erythritol is restricted. So the key in industry is how to improve the yield of erythritol, optimizing fermentative culture ingredients and fermentative conditions has become hot spot. In the experiment. we used the Candida mycoderma. which wa ultraviolet mutagenesis and cell fusion. to optimize the fermentative Firstly, we used single factor experiment to research, then, we app surface methodology to to optimize fermentative culture ingredients and conditions. We ensure the optimal fermentative culture ingredients, temperature, pH, et al. On the basis of previous studies, we use molasses as carbon source to replace glucose and corn syrup as nitrogen source to replace beef extract, yeast extract. If we can produce erythritol in the experiment, we can reduce cost of production mostly, transform molasses and corn syrup into functional food, satisfy the need of industry, reduce the pollution of the environment. It has wide application prospect in industry.Through the single factor experiment and response surface methodology experiment, the optimal fermentative culture ingredients is molasses43.0%, corn syrup2.1%, KH2PO44.7g/L, the optimal fermentative conditions is temperature32.3℃, pH5.1, the speed of wave bed176r/min, the yield of erythritol achieve167.10mg/ml. The yield of erythritol has been improved by optimization experiment. Make the experiment of the optimal conditions two times and take the average value. the yield of erythritol is166.89mg/mL. It fits well with the forecast value. It can show the regression equation provide a appropriate model.We make experiment in5L fermenter three times with fermentative conditions optimized last. The yield of erythritol is169.2mg/mL,171.7mg/mL.170.4mg/mL. the average value is170.4mg/mL. they all exceeded shake flask experiment. The yield has been improved enormously.The research and application of erythritol can improve people’s health, promote the development of the functional food industry. The experiment combined corn superiority of Jilin province, produce functional sugar alcohol. It provide new way to carry on corn deep processing. promote the development of local economic enormously.