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Development of a single kernel analysis method for detection of 2-acetyl-1-pyrroline in aromatic rice germplasm

Bryant, R. J., McClung, A. M., Grimm, C.
Sensing and instrumentation for food quality and safety 2011 v.5 no.5 pp. 147
Oryza sativa, aromatic compounds, brown rice, cultivars, gas chromatography, germplasm, ions, mass spectrometry, microextraction, progeny, seeds, volatile compounds
Because of the high demand for aromatic rice cultivars that command a premium, it is important to have efficient methods for determining 2-acetyl-1-pyrroline (2-AP), the aromatic compound found in rice, that can be used in breeding efforts and to detect aromatic/non-aromatic blended rice in the marketplace. Solid-phase microextraction (SPME) in conjunction with GC/MS was used to distinguish non-aromatic rice (Oryza sativa, L.) kernels from aromatic rice kernels. In this method, single kernels along with 10 µl of 0.1 ng µl-1 2,4,6-Trimethylpyridine were placed in sealed vials and heated to 80 °C for 18 min. During the heating stage volatile compounds, which include 2-AP, were adsorbed onto a SPME fiber. Volatiles were desorbed from the fiber and separated using gas chromatography. 2-AP was quantitated by mass spectrometry using the 111, 83 and 68 m/z ions. The method detected 2-AP in milled rice and brown rice; however, its detection in paddy rice was less successful. In a mixture of aromatic and non-aromatic rice, the aromatic rice kernels were differentiated from the nonaromatic rice kernels using the described method. Therefore, this method can be used to identify segregating from nonsegregating progeny during early generations in an aromatic rice breeding program when quantities of seed are very limited and can determine if aromatic rice has been adulterated with non-aromatic rice either through inadvertent mixtures, outcrosses or prepared blends.