Copy of author's previously published article inserted. Bibliography: leaves 180-195. Investigation of the contribution of polyphenol oxidase (PPO) and peroxidase (POD) to enzymic browning in sugarcane juice.

A mathematical model has been developed to represent the extraction of sugar from sugar cane in the diffusion process. As a consequence of the structure of prepared cane, extraction is postulated to occur via two first order relations in parallel. The model was found to represent accurately the extraction behaviour observed in two different experimental configurations. Experiments on a laboratory scale were undertaken to elucidate the mechanism and basic rates of extraction. The results are consistent with the postulate that extraction takes place by a combination of washing and molecular diffusion. The diffusion process was simulated experimentally in a fixed-bed pilot plant diffuser. Model parameter values estimated from this data provide evidence of the effect of liquid hydrodynamics on the extraction process. These results have been interpreted in terms of liquid holdup, liquid velocities and the efficiency of liquid- solid contacting. It is shown how the model can be applied to full scale diffusers of the moving-bed type, which will enable prediction of performance and the choice of optimum operating conditions. / Thesis (Ph.D.)-University of Natal, Durban, 1972.

Copy of author's previously published article inserted. / Bibliography: leaves 180-195. / xii, 195 leaves : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Investigation of the contribution of polyphenol oxidase (PPO) and peroxidase (POD) to enzymic browning in sugarcane juice. / Thesis (Ph.D.)--University of Adelaide, Dept. of Horticulture, Viticulture and Oenology, 1995