9407179 Burns ABSTRACT The activity of the enzyme pectinesterase in fresh-squeezed citrus juice greatly decreases the quality of the product. Because of its action on juice components, pectinesterase causes cloud loss in citrus juice. Presently, higher temperature pasteurization, above what is necessary for microbial control, is used commercially to reduce the activity of the enzyme. However, after pasteurization, residual pectinesterase activity persists, and flavor is negatively affected. Exploring alternative methods of pectinesterase control would be of major benefit in improving the quality of this valuable product. Dr. Burns is seeking to apply recent advances in recombinant DNA technology to substantially reduce the enzyme in citrus juice.
