Content area
Full Text
Eur Food Res Technol (2009) 229:99106 DOI 10.1007/s00217-009-1030-3
ORIGINAL PAPER
Development and validation of microscopical diagnosticsfor Tulsi (Ocimum tenuiXorum L.) in ayurvedic preparations
Gabriele Jrges Kathrin Beyerle
Michael Tossenberger Annette Hser Peter Nick
Received: 28 November 2008 / Revised: 3 February 2009 / Accepted: 9 February 2009 / Published online: 26 February 2009 Springer-Verlag 2009
Abstract During recent years, ayurvedic plants have entered the European market as a novel food trend. This confronts food analytics with the task to assess the composition of exotic and often unknown herbal preparations in teas or spices. Using the trend plant Tulsi (Holy Basil, Ocimum tenuiXorum L.) as model, we developed microscopical diagnostics on markers that can be reliably assessed in dried or even fragmented specimens as typically occurring in commercial ayurvedic preparations, where DNA extraction is diYcult. First, a reference for Tulsi was deWned based on the plastidic internal transcribed spacer (ITS) as marker. Second, this reference was morphologically delineated from other Ocimum accessions potentially used as surrogates for Tulsi (such as O. basilicumL.) leading to a microscopical assay based on the density of glandular scales and glandular hairs, the epidermis with trichomes and the cells of the palisade parenchyma. Third, this assay was statistically validated for its ability to discriminate surrogate species from true O. tenuiXorum. First applications of this assay on commercial Tulsi products demonstrated a high frequency of surrogate additions.
Keywords Basil Detection method
Internal transcribed spacer (ITS) Ocimum tenuiXorum L. Tulsi Validation
Introduction
During recent years, ayurvedic medical and spice plants have entered the European market as functional food. A prominent example for this trend is the Holy Basil Tulsi (Ocimum tenuiXorum L.), a plant central for Indian Ayurveda, esteemed for its beneWcial eVects on general constitution and health [1]. Tulsi is administered against headache, rheumatic pains and arthritis, but also malaria, fever and allergies. Ancient ayurvedic scriptures describe a protective eVect of Tulsi against insect bites and recommend to use this herb for air-cleaning [2]. The traditional use of Tulsi has been supported by scientiWc evidence for antioxidant and detoxifying eVects [3], as well as antibacterial, antiviral, and antifungal activity of oils extracted from Tulsi [4]. In addition, it seems to alleviate the symptoms of Diabetes mellitus [5]. These medical implications stimulated the...