Microscopic authenticity and purity of herbs and spices

Traditionally proven method for identifying plants

Feb 2024. In the case of herbs and spices, inferior raw materials or adulteration are increasingly common^[2]. We support you with microscopic analysis to check the authenticity of plant material, detect foreign bodies and prove the purity of your products.

Spices and herbs as natural raw materials

Spices are derived from many parts of the plant: leaves, flowers, fruits, pistils, buds, stigmas, rhizomes, bark, seeds, and roots, or from the whole plant. The term herbs refers to herbaceous plants with aromatic leaves.

Spices and herbs are used to add flavour, colour and aroma to foods and beverages. They are also used for their preservative and health-promoting properties ^{[1, 5]}. Because of their use as natural, unprocessed raw materials for food and/or medicines, they are an important part of the global market. Increasing demand often leads to the search for goods of lower quality if prices remain the same, or even to adulteration and thus overall contamination if prices rise.

Mandatory hygiene standards

In order to ensure excellent hygiene standards in the food production chain, both European legislation (EC Regulations 852/2004, 853/2004) and the German Federal Ministry of Food and Agriculture have laid down hygiene standards. For example, in monograph on the use of mint leaves, the European Pharmacopoeia stipulates that the raw material may contain a maximum of 5 percent stems and a maximum of 2 percent other foreign components per 10g of drug ^[9]. Attention must be paid to the presence of foreign substances, e.g. light solid contaminants of mineral, plant or animal origin or even whole insects ^{[4, 6, 7, 8]}.

Questions on microscopy of herbs and spices

If you have any questions about microscopy of herbs and spices, please get in touch with your personal account manager or contact our expert Dr Ghalia Kassem directly.

Relevant sources:

[1] Herbs, spices and essential oils (post-harvest operations in developing countries), © UNIDO and FAO 2005 — First published 2005
[2] Ichim MC, Häser A, Nick P. Microscopic Authentication of Commercial Herbal Products in the Globalized Market: Potential and Limitations. Front Pharmacol. 2020 Jun 9; 11:876. doi: 10.3389/fphar.2020.00876. PMID: 32581819; PMCID: PMC7295937
[3] Jürges G., Beyerle K., Tossenberger M., Häser A., Nick P. (2009). Development and validation of microscopical diagnostics for “Tulsi” (Ocimum tenuiflorum L.) in ayurvedic preparations. Eur. Food Res. Technol. 229, 99–106. 1007/s00217-009-1030-3
[4] Tilocca MG, Caneglias E, Vodret B, Mancuso MR, Zimmardi A, Manno C, Schiavo MR. Analysis of Foreign Matter in Foodstuffs Using the Light Filth Test: Report 2012-2013. Ital J Food Saf. 2015 Sep 25;4(3):4504. doi: 10.4081/ijfs.2015.4504. PMID: 27800401; PMCID: PMC5076630
[5] Jessica Elizabeth T, Gassara F, Kouassi AP, Brar SK, Belkacemi K. Spice use in food: Properties and benefits. Crit Rev Food Sci Nutr. 2017 Apr 13;57(6):1078-1088. doi: 10.1080/10408398.2013.858235. PMID: 26560460
[6] European Commission, 2004a. Regulation of the European Parliament and of the council of 29 April 2004 on the hygiene of food-stuffs, 852/2004/EC. In: Official Journal, L 139/1, 30/04/2004
[7] European Commission, 2004b. Regulation of the European Parliament and of the council of 29 April 2004 laying down specific hygiene rules for on the hygiene of foodstuffs, 853/2004/EC (consolidated text) . In: Official Journal, L 139/55, 30/04/2004
[8] German guidelines for spices and other seasoning ingredients (Federal Ministry of Food and Agriculture), 2008
[9] European Pharmacopoeia 10.0, 2020