Most consumers believe that herbal products must be harmless. The herbs and spices were used as ingredient in seasoning powder to flavor food for a long time without concern for their toxicity and adverse effects. The objective of this study was to evaluate the mutation possibility of Thai savory powder, namely Nua powder. Nine vegetables are normally used in the seasoning powder recipe: mulberry (Morus alba Linn.), horse radish tree (Moringa oleifera Lam.), bamboo grass (Tiliacora triandra (Colebr.)Diels., bustard cardamom (Albizia myriophylla Benth.), Chinese spinach (Amaranthus lividus Linn.), cowa (Garcinia cowa Roxb.ex DC.), chives (Allium schoenoprasum L.), Pak-wan tree (Melientha suavis Pierre.) and Kan tong (Colubrina asiatica L.ex Brongn.). The mutation evaluation was studied using the Ames test (reaction with and without nitrite salt). The experiments were conducted at the Institute of Food Research and Product Development (IFRPD) Kasetsart University from February 1 to 25, 2014. The samples were extracted using various solvents (dimethyl sulfoxide (DMSO) 80% methanol and hexane). After the reaction with /without nitrite salt, the extracts were further evaluated for mutation activity using Salmonella typhimurium strain TA98 and strain TA100 for detection of frameshift and base-pair substitution mutation, respectively. The extract was added at concentrations of 1.5, 7.5, 15 and 30 mg/plate into the plate culture to evaluate the correlation between the concentrations of the extracts and the number of bacterial colonies. The DMSO solvent and reaction without the nitrite salt system, did not exhibit any mutagenicity in the seasoning powder samples and all vegetables with either TA98 or TA100. In contrast, seasoning powder samples and four vegetables (horse radish tree, bamboo grass, chives and Kan tong) showed a weak positive mutation of S. typhinurium TA98. These results indicate that the extract from the four vegetables produced a direct mutagen after nitrosation. These four vegetables showed the same results, when 80% methanol was used as solvent. However, (bamboo grass and Kan tong hexane extract demonstrated weak mutagenic effect in the S. typhinurium colony after nitrosation, it can imply that the substance caused mutagenicity should be the polar compounds, because DMSO and methanol can extract polar substances but the hexane extract, did not show strong mutagenicity toward the bacterial colonies. © 2015 International Society for Southeast Asian Agricultural Sciences. All rights reserved.