The chapter describes current procedures for the safety assessment of genetically modified crops and foods. The concepts of substantial equivalence, the conventional comparator, and intended and unintended effects are introduced. Most published examples of substantial equivalence testing deal with crops that have been modified for insect resistance or herbicide tolerance. A standard procedure has developed based on broadly similar field trial designs, sampling schemes and targeted analyses of a consensus set of compounds for each crop. The main characteristics of the procedure are summarised with reference to published analyses of this type of crop and different statistical approaches to judging 'equivalence' are discussed. There is a current trend towards development of crops with enhanced nutritional properties or health-related benefits through genetic modification of metabolic pathways. These more complex modifications have greater potential for introducing unpredictable unintended effects, and it may be advisable to supplement current targeted analysis procedures with metabolomics methods. The second part of the chapter discusses the application of metabolomics to substantial equivalence testing. As yet there is no standard procedure for this approach so individual studies, which differ greatly in size and scope, are discussed. The major analytical techniques (GC/MS, LC/MS and NMR) are briefly described and examples of their use are given: a few studies have shown how the massive amounts of data produced by non-targeted profiling methods may be treated to judge equivalence. Some limitations need to be overcome before metabolomics can be adopted as part of the official safety assessment procedure.
|Title of host publication||Plant-derived Natural Products|
|Subtitle of host publication||Synthesis, Function, and Application|
|Number of pages||27|
|Publication status||Published - 2009|