Microscopic control of Rhizoma Curcumae Longae using multivariate analysis

Rhizomae Curcumae Longae is the dried rhizome of Curcuma longa L. (Zingiberaceae), commonly known as turmeric. This herbal material has a long history of traditional use for culinary purposes as a spice and as a food colorant. In Algeria, turmeric is known in Arabic as “Kurkuma”, and used in culinary and in traditional medicine [1]. This study was aimed at establishing the microscopic identification of different commercial samples and developing parameters for discriminating turmeric powders. Fifteen samples from different origins were analyzed, and each experiment was performed in triplicate. Statistical techniques were used to analyze the partition of the structure observations.

The homogeneity or the variability was investigated by multivariate test. Multiple Correspondence Analysis (MCA) was also applied in the course of the experiments, using SPSS Statistics 17.0 (Statistical Package for Social Sciences, SPSS Inc., Chicago, IL, USA, 2008). In consequence, eleven discriminating structure features were identified. The most diagnostic features are yellow clumps of gelatinized starch, covering trichome, starch granules, vessels, cork, and fibers. The results showed that microscopic observation of powder samples of rhizoma Curcumae longae could be grouped according the presence of non-glandular trichome, and calcium oxalate crystals clusters. Moreover, it appeared that the presence of calcium oxalate cluster is a discriminated parameter of the group II and differentiated between subgroups. Indeed, this criterion is rarely observed and is present only in three observations of the subgroup II-1. These findings revealed that microscopic analysis, coupled with statistical methods, could provide a simple platform for medicinal plant identification, particularly for the diagnostic authentication of commercial samples.

References:

[1] Bouzabata A, Boukhari A. Variation in the Traditional Knowledge of Curcuma longa L. in North-Eastern Algeria. International Journal of Biological, Veterinary, Agricultural and Food Egineering 2014; 8: 1141 – 1145