A microbial characterization of cocoa powder and chocolate bars of three batches of five
different brands sold in Italian markets was performed. The results showed a variable microbial
population consisting of mesophilic and thermophilic spore formation in both types of products.
The chocolate bars were also contaminated with molds of environmental origin. Bacillus spp. and
Geobacillus spp. were found in both products. The chocolate bars were also contaminated by molds
belonging to the genera Penicillium and Cladosporium. The sporogenous strains mainly originate
from the raw materials, i.e., cocoa beans, as the heat treatments involved (roasting of the beans and
conching of the chocolate) are not sufficient to reach commercial sterility. Furthermore, the identified
spore‐forming species have often been isolated from cocoa beans. The molds isolated from
chocolate seem to have an origin strictly linked to the final phases of production (environment and
packaging). However, the level of contaminants is limited (<2 log CFU/g); the molds do not develop
in both products due to their low Aw (<0.6) and do not affect the safety of the products. However,
a case of mold development in chocolate bars was observed. Among the isolated molds, only Penicillium
lanosocoeruleum demonstrated a high xero‐tolerance and grew under some conditions on
chocolate bars. Its growth could be explained by a cocoa butter bloom accompanied by the presence
of humidity originating from the bloom or acquired during packaging.
