Abstract
Optimal conditions of enzymic destruction of plant substrates were studied. The effectiveness of action of fungal cellulase, produced by a strain of Trichoderma viride, and of the pectolytical preparation Pectophoetidin were tested on a laboratory scale. The loss of dry matter on the sieve 0.4 mm mesh served as an effectiveness criterion of enzyme action. The concentration of reducing substances in the filtrate was determined simultaneously as an orientational measure of the content of lower cleavage products of cellulose and pectin. Correlation between the two criteria was proved. The effects of the concentration and ratio of the two enzymes were tested in the range of the cellulase and pectinase concentrations of 0.925–9.250, and 0.414–12.432 IU/g fresh substrate, respectively. The results show that the optimal system of the mixed enzymic preparations consists of 3.700 IU cellulase and 4.144 IU pectinase/g substrate. In this case, the required maximal degree of substrate liquefaction (1.0–1.5% of residual dry matter) was achieved after 3 h of incubation at 30 °C. Simultaneously, the content of provitamin A was determined in the suspension before and after the enzymic treatment. The enzymic destruction of cellular walls resulted in an improved releasement of provitamin A from the cells and thus in an 25% enhancement of its concentration in the suspension.