Comparative Chemical Evaluation of Commercially Available Mint Hydrosols Produced in Fars Province, Iran

Background: Hydrosols of Mentha species are a common beverage among Iranians. The product quality may differ depending on the type of material used and the distillation process. However, despite the many investigations on the chemical composition of different mint essential oils, the co-produced hydrosols have rarely been evaluated. 
Objectives: This study evaluated and compared the chemical composition of 10 mint hydrosol samples purchased from local markets of Fars province, Iran, to Mentha piperita and Mentha spicata authentic hydrosols. 
Materials and Methods: Essential oils of the samples were extracted via liquid–liquid extraction by petroleum ether and analyzed using gas chromatography–flame ionisation detector (GC-FID) and gas chromatography–mass spectrometry (GC-MS). Hydrosols were then clustered based on their components. 
Results and Conclusion: Approximately 91.3%–100% of the components and overall 31 constituents were identified with the majority of oxygenated monoterpenes. Menthol, (R)-(−)-carvone, and piperitenone were the three different major compounds in the market samples. High percentages of menthol and carvone in many samples suggest that each product could be biologically active, and moreover, could be a valuable water-soluble source of their constituents. However, lack of chemical evaluation and standardization in this industry leads to inconsistency in quality and undermines the credibility of the industry.