Fungi Associated with Softening of Bisulfite-Brined Cherries

Softening of sound, calcium bisulfite-brined cherries was induced fairly quickly by brining them with cherries rotted byAspergillus niger, Cytospora leucostoma , andPenicillium expansum , but not with cherries rotted by a variety of other microorganisms, includingAlternaria sp.,Aspergillus oryzae, Aureobasidium pullulans, Botrytis cinerea, Cladosporium sp.,Mucor racemosus, Rhizopus stolonifer , andSclerotinia fructicola . Rapid softening was correlated with the presence of a bisulfite-stable polygalacturonase, as demonstrated by a cup-plate test. A survey of naturally rotted cherries suggests the involvement of a bark-canker fungus,C. leucostoma , in softening of commercially brined cherries in the Pacific Northwest.