Blue mold disease or wet rot disease

The most prevalent mold and the one causing the most damage is the ‘blue mold’, otherwise known as ‘Penicillium expansum’. It first appears usually as a white cottony growth on fruits, cheese, cured meats, vegetables, jellies, wine tanks, leather left in dark closets, and on other article favorable to its growth.

Blue mold is the most economically important postharvest disease of apples. The disease, also known as soft rot or wet rot, causes substantial losses in the United States, Canada, England and many other countries.

The blue mold can be controlled, but great care must be taken if it is to be completely eliminated. Its spores can be killed by heating to 82 °C, and growth is prevented with many chemicals.

However acquired resistance by Penicillium italicum and Penicillium digitatum to fungicides used on citrus fruit has become a matter of concern in recent years.

The term blue mold may also be applied to Penicillium roqueforti, a mold used in producing the taste and characteristic blue-green inclusions in Roquefort and other blue cheeses. Blue cheeses are typified by a semisoft texture and blue mold growing throughout the curd.  

Penicillium roqueforti produces the mottled blue color and laws gives rise to fatty acid ketones which contribute to the characteristics sharp, peppery flavor of these cheeses.

Mold growth is encouraged during the ripening period which can be from 3 to 10 months at cool, moist, cavelike conditions of about 4 ° C and 90% RH.
Blue mold disease or wet rot disease