Analysis of flavor volatiles of some Iranian rice cultivars by optimized static headspace gas chromatography–mass spectrometry

Abstract

Static headspace coupled to gas chromatography–mass spectrometry (SHS-GC–MS) was applied to the extraction and analysis of volatiles in some Iranian rice varieties. Optimization of static headspace sampling was investigated by full factorial design and a face-centered central composite design procedure. According to the results of full factorial design, the effective parameters of static headspace sampling were extraction temperature (T) and extraction time (t). Then a central composite design was applied to find the optimum level of these factors. The results of three replications of experiments under optimal conditions (T = 100 °C, t = 900 s) indicated that, there is a good agreement between the predicted (5.28) and experimental (5.20) responses (98.48 %). Then developed method was used for analysis of volatile chemicals in three Iranian rice cultivars. According to the results of GC–MS analysis 26, 21, and 19 chemicals were assigned to Domsiah, Deylamani, and Tarom rice samples, respectively. The major compounds identified in these samples were the alkyl aldehydes. The results obtained are promising for future isolation and identification of the flavor volatiles of other rice cultivars by SHS-GC–MS analysis. The method of static headspace GC–MS has been developed and has proven to provide an effective means for simple and rapid quantitative analysis of the aroma compound of rice. A central composite design was applied to found the optimal conditions. The results of three replications of experiments under optimal conditions (T = 100 °C, t = 900 s) indicated that, there is a good agreement between the predicted (5.28) and experimental (5.20) responses (98.48 %). Then, developed method was used to analyze the volatile chemicals in the rice samples. A total of 26, 21, and 19 chemicals were assigned to Domsiah, Deylamani, and Tarom rice samples, respectively.