B. Sasikumar

PCR Based Detection of Adulteration in the Market Samples of Turmeric Powder

Abstract This article describes an efficient, relatively original method for the detection of extraneous Curcuma Sp. contamination in the powdered market samples of turmeric using molecular markers (RAPD), which are not easily discriminated by other analytical techniques routinely used for the identification of adulterants in powdered market samples of turmeric. Three market samples of turmeric powder studied revealed the presence of more Curcuma zedoaria (wild species) powder than Curcuma longa (the common culinary turmeric) powder, though the curcumin levels of the samples tallied with the quality standards prescribed for the commodity.

Isolation and amplification of DNA from rhizomes of turmeric and ginger

Turmeric and ginger are used as spices and in alternative systems of medicine. They are rich in polysaccharides, polyphenols, and alkaloids. A simple and rapid method for isolating good quality DNA with fairly good yields from mature rhizome tissues of turmeric and ginger has been perfected. Isolated DNA was amenable to restriction digestion and PCR amplification.

DNA Barcoding to Detect Chilli Adulteration in Traded Black Pepper Powder

Value-added forms of black pepper (Piper nigrum L.) are an important item of trade globally. Adulteration by default or design of the commodity not only leads to economic loss and public health issues but also to self-respect of a nation. DNA barcoding is assuming significance as a quality assurance technique in many agri-food commodities. Three barcoding loci viz., psbA-trnH, rbcL, rpoC1 were used in the study to detect bio adulteration of traded black pepper powder. PCR amplification of P. nigrum and traded black pepper powder was performed for all the three loci. Sequence analysis and BLAST results revealed chilli adulteration in two out of nine market samples, originating probably from exhausted black pepper powder fortified with chilli. Of the three loci, psbA-trnH proved to be the best and ideal for detection of chilli adulteration in black pepper yielding amplicons of size 600 bp and 350 bp, respectively. Cloning and sequencing of the adulterant specific band of both market samples were done to confirm the results. It was further validated using simulated samples of chilli and black pepper powders in various proportions. The method proved efficient to detect adulteration even at very low levels (0.5% adulteration). HPLC analysis also supported the chilli adulteration of black pepper powder. The method is easy, reliable and efficient, and can be used by the regulatory agencies for quality assurance of black pepper powder.

Development and Application of SCAR Marker for the Detection of Papaya Seed Adulteration in Traded Black Pepper Powder

The present study reports the development of a specific, sensitive, and reproducible Sequence Characterized Amplified Region (SCAR) marker to detect papaya seed powder adulteration in traded black pepper powder. A putative RAPD marker (449 bp) specific to papaya seed was identified, cloned, and sequenced to design the SCAR primers. This specific SCAR marker could detect the presence of papaya seed in all the analyzed simulated standards and in one of five branded market samples of black pepper powder tested. The analytical strategy being very simple could be used for large scale screening of powdered black pepper market samples intended for export and domestic uses.

Biochemical variation in turmeric (Curcuma longa Linn.) accessions based on isozyme polymorphism

SummaryFifteen accessions of Curcuma longa L. collected from different geographical areas in India, along with a few seedling progenies, were studied for variation based on isozyme polymorphism. A high degree of variability (63.8–96% similarity) was seen in the population studied. Phenetic analyses revealed several groups with interesting features. Two seedling progenies, which showed maximum similarity, stood distinctly from the clonally propagated material. Other pairs of accessions showing high similarity (above 90%), were from the same geographical area, indicating that accessions collected based on vernacular names and those collected from adjoining areas, need not be genetically distinct.

Detection of plant-based adulterants in turmeric powder using DNA barcoding

Abstract Context: 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. Materials and 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. Discussion and conclusion: 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 products 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.

SCAR markers for adulterant detection in ground chilli

Purpose – This study aims to treat the development and application of sequence characterised amplified region (SCAR) markers for the detection of plant based adulterants (dried red beet pulp and powdered Ziziphus nummularia fruits) in traded ground chilli.Design/methodology/approach – Adulterant‐specific DNA fragments (red beet pulp specific – “Beet 01” and Z. nummularia specific – “Ziz 01”) identified by random amplified polymorphic DNA polymerase chain reaction (RAPD‐PCR) analysis were cloned and sequenced for SCAR marker development. Red beet pulp specific SCAR primer pair, B1, and Z. nummularia specific SCAR primer pair, Z1, were designed from the corresponding RAPD marker sequences to amplify SCAR markers of 320 bp and 389 bp, respectively. The utility of the SCAR markers for adulterant detection was verified in model blends of chilli powder with the adulterants. Six commercial samples of ground chilli powder were analysed using the SCAR markers.Findings – SCAR markers could detect the adulterants at...

DNA Barcoding for Discriminating the Economically Important Cinnamomum verum from Its Adulterants

Traded forms of spice and spice powders are often subjected to admixing with inferior substances by design or default, affecting public health and national prestige. Cinnamomum verum (true cinnamon), a high-value spice, is often adulterated with its inferior species such as C. cassia and C. malabatrum. The presence and detection of the spurious species in traded barks (whole or powder) of true cinnamon is posing problems. DNA markers are now used to detect such adulteration. Here we report the application of a DNA barcoding method to detect these adulterants in traded market samples of true cinnamon using the barcoding loci rbcL, matK and psbA-trnH. The PCR success rate, sequencing efficiency, inter and intra specific divergence, and occurrence of single nucleotide polymorphisms (SNPs) were utilized to assess the potential of each barcode loci to authenticate C. verum from its related adulterants. The amplification and sequencing success was 100% for rbcL and psbA-trnH while matK failed to amplify in the market samples. The locus of rbcL showed higher interspecific divergence while psbA-trnH exhibited lower interspecific divergence. SNPs specific to C. cassia were detected in rbcL locus in seven out of the ten market samples studied thereby confirming the presence of C. cassia adulteration in commercial samples of true cinnamon. Out of the three loci, rbcL locus proved to be efficient in tracing out adulterants in traded cinnamon. The SNP sites in this locus can be exploited in designing C. cassia specific primers, enabling kit development for easy detection of adulterants at the band level itself thereby bypassing the cost of sequencing.

Isolation and PCR amplification of genomic DNA from dried capsules of cardamon (Elettaria cardamomum M.)

Cardamom is an important spice, condiment and medicine, and international commodity. DNA-based molecular profiling will be aid in protecting the intellectual property rights of those who trade cardamom on the world market. Commercial cardamom has so far proven recalcitrant to traditional DNA extraction methods. In this paper we report a protocol for the isolation of amplifiable genomic DNA from traded cardamom. The method involves a modified CTAB (hexadecyltrimethylammonium bromide) extraction step, followed by a purification step to remove polysaccharides, proteins, and polyphenols, which are abundant in storage tissue such as cardamom capsules. The yield of DNA was 6–7 μg g−1 tissue. Spectrophotometric and electrophoretic analysis indicated that the isolated DNA was highly pure and of high molecular weight. The isolated DNA could be amplified using different random decamer primers. The protocol has trade implications as it will help in the PCR-based characterisation of traded cardamom. This protocol can be further extended to develop Sequence Characterised Amplified Regions (SCAR) markers for profiling cardamoms.

CHARACTERIZATION OF TWO INTERSPECIFIC HYBRIDS OF PIPER

SummaryTwo interspecific hybrids of Piper, P. nigrum x P. attenuatum and P. nigrum x P. barberi, produced for the first time, were characterized by morphology, anatomy, isozymes, cytology and function (reaction to pollu beetle). The hybrids exhibit distinct morphological and anatomical features. Hybrid-specific bands as well as male-specific bands were observed in the zymograms of the isoforms of three of the four isozymes, peroxidase, esterase and polyphenol oxidase. Paired affinity index of the four enzymes revealed more similarity between the female parents and hybrids than between the male parents and hybrids. The hybrids had the same chromosome number (2n.=.52) as their parents. The leaves of the hybrids were less preferred for feeding by pollu beetles when compared with their female parents. Successful hybridization among the three species belonging to the same subgenus Maricha confirms their phylogenic relationship.