Development of advanced analytical tools to determine the origin of caviar

Abstract

Summary Whereas reliable mtDNA-based methods for species identification of sturgeon caviar are at hand, the development of techniques to separate populations (stocks) or different sources (wild vs farmed) is presently at a preliminary state. We tested three methods, Differential Scanning Calorimetry, determination of stable isotopes (δ15N and δ13C), and mRNA analysis (reverse transcription polymerase chain reaction), for their diagnostic power for population and/or source identification of caviar. Farmed caviar (Acipenser baerii) from northern Germany and caviar samples presented by a trading company (Huso huso, Acipenser stellatus, Acipenser gueldenstadtii, Acipenser persicus from Iran and Kazakhstan) were included. Firstly, several DNA-based methods (single strand conformation polymorphism analysis, restriction fragment length polymorphism, sequence analysis) were used for species identification. Sequence analysis of cytb showed the largest diagnostic power. According to population and source identification issue, we conclude that all three methods have considerable potential. Nevertheless, additional methods like fatty acid profiling should be added for a reliable identification of populations and sources.