Improving the application of SSR polymorphism analysis coupled with Lab-on-a-chip® capillary electrophoresis to assess food authenticity: Italian pigmented rice as case study

Genetic distances evaluated via SSR-based profiling can be usefully assessed by using capillary electrophoresis. In order to set up a method to distinguish pure Italian rice varieties from imported Asian blends, seven Italian rice genotypes and seven uncharacterized rice samples coming from outside Italy were studied using a classical SSR polymorphism analysis coupled with Lab-on-a-chip® microcapillary electrophoresis. A special algorithm for the elaboration of the raw outputs provided by the software was generated, thus overcoming the problems connected to the instrument intrinsic limits of resolution. The results showed that even considering just the smallest verifiable genetic distance between the employed samples, locally cultivated Italian rice varieties clustered separately from other foreign cultivars. Moreover, it was possible to clearly identify an artificial blend formed by Venere rice mixed with a black variety from Thailand, thus confirming the usefulness of this new post-analysis approach.