Identification of undeclared ingredients in red pepper products sold on the South Korea commercial market using real-time PCR methods

Red pepper is one of the most important spices in the Republic of Korea, and fraudulent practices during manufacturing of red pepper products can cause social concerns. In this study we conducted the regulatory survey to verify the labeling compliance of red pepper products sold on the South Korea commercial market. We designed species-specific primer sets for five common ingredients (red pepper, garlic, onion, spring onion, and ginger) and developed reliable real-time polymerase chain reaction (PCR) methods using SYBR Green I dye to identify the ingredients used in red pepper products. Sixty-six commercial red pepper products were analyzed using our real-time PCR methods for the presence of potential mislabeling. The results of fifty-one samples were consistent with their labeling information, whereas the results for fifteen samples, described as red pepper powder and seasoned red pepper sauce, did not satisfy their manufacturing criteria. Our findings demonstrated that the developed real-time PCR methods could be efficiently utilized for rapid monitoring of commercial red pepper products.