Microorganisms have long played a major role in
the production of food (dairy, fish and meat
products) and alcoholic beverages. In addition,
several products of microbial fermentation are
also incorporated into food as additives and
supplements (antioxidants, flavors, colorants,
preservatives, sweeteners, etc.). There is great
interest in the development and use of natural
food and additives derived from microorganisms,
since they are more desirable than the synthetic
ones produced by chemical processes. Solid-state
fermentation (SSF) reproduces the natural
microbiological processes like composting and
ensiling. In industrial applications this natural
process can be utilized in a controlled way to produce a desired product. Typical examples of it
are the fermentation of rice by Aspergillus oryzae
to initiate the koji process and Penicillium
roquefortii for cheese production. (Susana et
al)[32]
SSF is defined as any fermentation process
performed on a non-soluble material that acts
both as physical support and source of nutrients in
absence of free flowing liquid. The low moisture
content means that fermentation can only be
carried out by a limited number of
microorganisms, mainly yeasts and fungi, although
some bacteria have also been used. Some
examples of SSF processes for each category of
microorganisms are reported in Table 3.