摘要 |
A low cost process for producing concentrated fructose is described which involves selective, preferential biological utilization of glucose in mixtures of glucose and fructose, in order to thereby yield concentrated fructose. Broadly speaking, the method involves contacting a mixture containing respective amounts of glucose and fructose with a microorganism which preferentially utilizes glucose as compared with fructose, incubating the mixture until the relative concentration of fructose is substantially in excess of that of glucose, and recovering concentrated fructose. In preferred forms, the microorganism is Pullularia pullulans, and the starting material may be a mixture of gluctose and fructose, sucrose, a carbohydrate such as inulin or starch; in the latter instances, the P. pullulans, by virtue of excretion of invertase, acts to degrade the starting material to give the desired glucose-fructose mixture. Recovery procedures such as ion exchange, evaporation and/or crystallization give highly concentrated or essentially pure fructose. A biopolymer side product resulting from glucose utilization by the preferred microorganism can also be recovered if desired.
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