CANNED APRICOTS in Australia are believed to be softened by heat-tolerant pectolytic enzymes from the black bread mold, Rhizopus stolonifer (Ehrenb. ex Fr.) Lind. Australian workers have duplicated softening problems by adding a Rhizopus-rotted fruit or juice from a rot lesion to cans. Fungi were killed by heat-processing at 100°C (212°F) for 10 minutes but a portion of their pectolytic enzyme activity remained. The Australian work has now been duplicated independently in two California studies.