Biotransformation of α- and β-pinene into flavor compounds

The recent approval of fungal carotenoids as food colorants by the European Union has strengthened the prospects for fungal cell factories for the production of polyketide pigments. Fungal production of colorants has the main advantage of making the manufacturer independent of the seasonal supply of raw materials, thus minimizing batch-to-batch variations. Here, we review the potential of polyketide pigments produced from chemotaxonomically selected non-toxigenic fungal strains (e.g. Penicillium and Epicoccum spp.) to serve as food colorants. We argue that the production of polyketide azaphilone pigments from such potentially safe hosts is advantageous over traditional processes that involve Monascus spp., which risks co-production of the mycotoxin citrinin. Thus, there is tremendous potential for the development of robust fungal production systems for polyketide pigments, both to tailor functionality and to expand the color palette of contemporary natural food colorants.

During the past years biocatalytic production of fine chemicals has been expanding rapidly. Flavours and fragrances belong to many different structural classes and therefore represent a challenging target for academic and industrial research. Here, we present a condensed overview of the potential offered by biocatalysis for the synthesis of natural and natural-identical odorants, highlighting relevant biotransformations using microorganisms and isolated enzymes. The industrial processes based on biocatalytic methods are discussed in terms of their advantages over classical chemical synthesis and extraction from natural sources. Recent applications of the biocatalytic approach to the preparation of the most important fine odorants are comprehensively covered.