Acid hydrolysis of potatoes under pressure

Conclusion

The acid hydrolysis of potatoes does not appear promising as a method of processing cull and surplus potatoes for storage or transportation. Elevated pressures do not seem to have much advantage, although they produce results in a shorter time or with less acid. To avoid decomposition, high acid concentrations would be required, and the resulting syrups would be difficult to concentrate. The statement, “In order to be suitable for commercial use, the agent promoting hydrolysis must give a high rate of hydrolysis as compared with the rate of sugar decomposition” (3) applies with the same force to the hydrolysis of potatoes as to the hydrolysis of wood cellulose. The rate of decomposition of potato hydrolyzates seems to increase more rapidly with temperature than the rate of hydrolysis, and the ratio is more favorable for wood cellulose than for potatoes. This method of hydrolysis is more promising when the hydrolyzates are to be used as fermentation substrates and when it is not necessary to hydrolyze the starch completely to glucose. Relatively high acid concentrations and close control would be required to keep decomposition to a minimum. Under properly controlled conditions, the results might well be satisfactory. Use of the material as a fermentation substrate would not require the expensive concentration step.