Two strategies are generally used in selecting a market for functional foods: market opportunity-driven and value-added driven that will benefit from the new attributes.
The components of botanical extracts related to the physiological systems are principally dietary fibres, prebiotics and secondary plant metabolites, principally polyphenols, terpenoids, alkaloids, unsaturated fatty acids, glucosinolates, polyacetylenes, and betalains.
New functional extracts can be selected from raw materials exploring the genetic variation, including under-utilised and unconventional plants or introducing genetic changes in common crops. The content of functional ingredients in raw materials and primary products can also be influenced by agricultural practices, biotechnological approaches (using enzymes and microorganisms) and separation processes, which led to refined products. Purification of components or fractions using molecular separation technologies, like subcritical and supercritical extraction.
The second step is the identification of the relationship between the components of the extracts and the health benefit (target function). Diverse modern approaches can be used to demonstrate the efficacy of the constituents of the selected extracts—namely their interaction with genes, a field called nutrigenomics, the integration of genomic science with nutrition. Although genes are critical for determining function, nutrition modifies the extent to which different genes are expressed and thereby modulates whether individuals attain the potential established by their genetic background.
New proteomic and metabolomic methods are now emerging that offer exciting opportunities for identifying the multiple molecular targets for components of the extracts and thus for determining mechanisms by which they influence the quality of life.
These opportunities will necessitate the characterisation of phytochemical-gene-protein dynamics which requires the application of these new analytical technologies that enable scientists to more fully explore the regulation of RNA transcription (transcriptomics), the profile of proteins encoded by these genes (proteomics), and ultimately the metabolic consequences of such changes (metabolomics).
A further step is assessing the stability and bioavailability of bioactive substances in botanical matrices. Long-term stability tests must assess the efficacy of bioactive compounds in marketed products. Manufacturers also can use the test results to establish a product shelf life that assures maximum efficacy. Furthermore, a bioactive substance cannot exert its beneficial effects unless it is bioavailable. Processes such as coating, microencapsulation, emulsification and, more recently, nanocarriers may optimise absorption and bioavailability of the bioactives. In particular, nanocarrier systems such as micelles, vesicles, polymeric nanoparticles, solid lipid nanoparticles, micro- and nanoemulsions are successfully applied as promising delivery systems for many bioactive constituents and essential nutrients in order to improve their uptake, absorption, bioavailability and slow release compared to bulk equivalents.