title: Detection of plant-based adulterants in turmeric powder using DNA barcoding.
abstract: BACKGROUND
  In its powdered form, turmeric [Curcuma longa L. (Zingiberaceae)], a spice of medical importance, is often adulterated lowering its quality.
  
  
  OBJECTIVE
  The study sought to detect plant-based adulterants in traded turmeric powder using DNA barcoding.
  
  
  METHODS
  Accessions of Curcuma longa L., Curcuma zedoaria Rosc. (Zingiberaceae), and cassava starch served as reference samples. Three barcoding loci, namely ITS, rbcL, and matK, were used for PCR amplification of the reference samples and commercial samples representing 10 different companies. PCR success rate, sequencing efficiency, occurrence of SNPs, and BLAST analysis were used to assess the potential of the barcoding loci in authenticating the traded samples of turmeric.
  
  
  RESULTS
  The PCR and sequencing success of the loci rbcL and ITS were found to be 100%, whereas matK showed no amplification. ITS proved to be the ideal locus because it showed greater variability than rbcL in discriminating the Curcuma species. The presence of C. zedoaria could be detected in one of the samples whereas cassava starch, wheat, barley, and rye in other two samples although the label claimed nothing other than turmeric powder in the samples.
  
  
  CONCLUSIONS
  Unlabeled materials in turmeric powder are considered as adulterants or fillers, added to increase the bulk weight and starch content of the commodity for economic gains. These adulterants pose potential health hazards to consumers who are allergic to these plants, lowering the product's medicinal value and belying the claim that the product is gluten free. The study proved DNA barcoding as an efficient tool for testing the integrity and the authenticity of commercial products of turmeric.
authors: Division of Crop Improvement and Biotechnology, Indian Institute of Spices Research , Kozhikode, Kerala , India.
authors: V A
authors: VA
authors: Parvathy
authors: V P
authors: VP
authors: Swetha
authors: T E
authors: TE
authors: Sheeja
authors: B
authors: B
authors: Sasikumar
mesh_terms: D030024:Curcuma / Q000235:genetics*; D058893:DNA Barcoding, Taxonomic / Q000379:methods*; D005506:Food Contamination / Q000032:analysis*; D010936:Plant Extracts / Q000032:analysis* / Q000235:genetics*; D011208:Powders; D027343:Rhizome
chemical_list: D010936:Plant Extracts; D011208:Powders; C012596:turmeric extract
keywords: Cassava; Curcuma zedoaria, fillers, ITS, rbcL, reference library, wheat