Plant-Based Adulterants Found in Common Spices

The Indian Institute of Spices Research (IISR), Kozhikode, identified plant-based adulterants in several spices sold in domestic markets. After conducting research beginning in 2010, scientists detected adulteration in black pepper, chilli powder, turmeric, cinnamon bark and mace. Their findings highlighted the use of advanced technologies, including DNA barcoding, to detect and analyse adulterants in spices.

Dr. B. Sasikumar, Head of the Crop Improvement and Biotechnology Division at IISR, shared the research findings through scientific publications and other official channels.

In an interview, Dr. Sasikumar explained that researchers collected five samples of nutmeg mace from local markets in Kozhikode, Kerala, and found that three samples contained Bombay mace, an inferior-quality adulterant commonly used as a natural dye.

Bombay mace is yellow, lacks the characteristic aroma of genuine mace, and has a lower quality. Researchers also highlighted the difficulty of distinguishing between genuine mace and the adulterant when the spice dries, ages, or undergoes powdering, as these processes diminish its characteristic features.

Financial reward remains the foremost incentive for systematic adulteration in India.

Dr. Sasikumar further explained that ageing causes genuine nutmeg mace to turn yellow, potentially allowing it to command a premium price. Unscrupulous traders may exploit this price difference by mixing genuine mace with inferior alternatives to increase their profits.

Turmeric Adulteration

Researchers also analysed 10 samples of turmeric and found adulteration in three samples. The adulterant primarily included wild turmeric, locally known as manja koova in Malayalam. The researchers also identified fillers such as wheat flour, barley powder and cassava starch in turmeric samples. These findings highlight how traders can dilute genuine spices with cheaper ingredients, compromising product purity and authenticity.

Black Pepper and Chilli Powder Adulteration

Researchers analysed nine branded market samples of black pepper powder and found that two samples contained chilli powder as an adulterant. The researchers also found that chilli powder sold in Kerala markets contained powdered fruits of choti ber, another plant-based adulterant. These findings demonstrate how cheaper plant materials can enter the spice supply chain and compromise the authenticity of products sold to consumers.

Cinnamon Adulteration

The analysis of cinnamon bark also revealed concerning findings. Researchers detected cassia, a closely related spice, in seven out of 10 market samples tested for adulteration. Although cinnamon and cassia share similarities in appearance and culinary use, they come from different plant species. Their resemblance can make it difficult for consumers to distinguish between them through visual inspection alone.

DNA Barcoding to Detect Spice Adulteration

Dr. Sasikumar also highlighted the importance of the institute’s research methodology, particularly the use of DNA barcoding to detect adulteration in spices. He described the technology as a reliable method for identifying adulterants and assessing the authenticity of tested samples. Conventional techniques, including physical, chemical, biochemical, and immunological methods, can be useful in specific situations. However, they may not be suitable for detecting every type of adulteration, particularly when adulterants closely resemble genuine spices.

In contrast, DNA barcoding identifies species by analysing short, specific sequences of DNA. Researchers can use this technique to identify the plant species present in a sample and detect substitutions that conventional methods or visual inspection may miss.

By helping researchers identify plant-based adulterants, DNA barcoding offers an additional tool for verifying spice authenticity and strengthening quality-control efforts. Such scientific methods can support efforts to detect food adulteration, protect consumers, and maintain the quality of spices available in domestic markets.