Key-Marker Volatile Compounds in Aromatic Rice ( Oryza sativa ) Grains: An HS-SPME Extraction Method Combined with GC×GC-TOFMS

• Published in: Molecules (Basel, Switzerland) Switzerland), 2019-11, Vol.24 (22), p.4180
• Main Authors: Setyaningsih, Widiastuti, Majchrzak, Tomasz, Dymerski, Tomasz, Namieśnik, Jacek, Palma, Miguel
• Format: Article
• Language: English
• Subjects: Adsorption; Aroma; Aromatic compounds; aromatic rice; Chemical compounds; Chromatography; Coefficient of variation; Cultivars; Design optimization; Fractional factorial design; Gas chromatography; Gas Chromatography-Mass Spectrometry; Headspace; Hexanal; Markers; multi-response optimisation; Multivariate analysis; Odorants; Oryza - chemistry; Principal Component Analysis; Principal components analysis; Pyridines; Solid Phase Microextraction; Solid phases; Spectrometry; Volatile compounds; Volatile Organic Compounds - isolation & purification
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules24224180

The aroma of rice essentially contributes to the quality of rice grains. For some varieties, their aroma properties really drive consumer preferences. In this paper, using a dynamic headspace solid-phase microextraction (HS-SPME) system coupled to a two-dimensional gas chromatography (GC×GC) using a time-of-flight mass spectrometric detector (TOFMS) and multivariate analysis, the volatile compounds of aromatic and non-aromatic rice grains were contrasted to define some chemical markers. Fifty-one volatile compounds were selected for principal component analysis resulting in eight key-marker volatile compounds (i.e., pentanal, hexanal, 2-pentyl-furan, 2,4-nonadienal, pyridine, 1-octen-3-ol and ( )-2-octenal) as responsible for the differences between aromatic and non-aromatic rice varieties. The factors that are most likely to affect the HS-SPME efficiency for the aforementioned key-marker compounds were evaluated using a 2 I I I 5 - 2 fractional factorial design in conjunction with multi-response optimisation. The method precision values, expressed as % of coefficient of variation (CV), were ranging from 1.91% to 26.90% for repeatability ( = 9) and 7.32% to 37.36% for intermediate precision ( = 3 × 3). Furthermore, the method was successfully applied to evaluate the volatile compounds of rice varieties from some Asian countries.