ABSTRACT:
Unavae marunthu” (meaning “food is medicine”) is a classical and extraordinary discovery of Siddha system of medicine. Rasam, is a very popular spice soup and it is consumed on daily basis in every South Indian home especially in Tamil Nadu. Literatures are available for the ingredients used in the preparation of rasam, but the details of chemical constituents present in rasam were not available. Hence, the present study was planned to study rasam in a stage wise manner and to analyse its chemical constituents by gas chromatography–mass spectrometry. Rasam was prepared in a five stage process to evaluate the significance of the traditional processing. Four samples (RS1, RS2, RS3 and RS4) at different stages of preparation were studied by gas chromatography–mass spectrometry. Stage wise preparation of rasam from RS1 to RS4 showed completely altered chemical composition. The only chemical constituent retained from RS1 to RS4 was 1,2-benzenedicarboxylic acid diethyl ester. 5-(propenyl-2)-1,3,7-nonatriene and di-n-octyl phthalate were retained from RS1 to RS3 but both the constituents were not present in RS4. 4h-pyran-4-one, 2,3-dihydro-3,5-dihydroxy-6-methyl and mome inositol were retained from RS3 to RS4. The major constituent in RS4 was found to be guanosine. Altered chemical composition may be due to breakdown of certain chemical constituents and/or formation of new chemical entities (NCEs).