Rapid gas chromatographic technique for quantifying 2-acetyl-1-pyrroline and hexanal in rice (Oryza sativa, L.).

ABSTRACT The aroma of rice plays a role in its consumer acceptability. The popcorn-like smell of aromatic rice stemming primarily from its 2- acetyl-1-pyrroline (2-AP) content is considered desirable by many consumers. Conversely, hexanal has been correlated with off odors in rice that develop from lipid oxidation. A rapid method for 2-AP and hexanal quantification suitable for use in breeding programs, large-scale research efforts, and quality assurance programs is needed. While developing such a method, sample preparation (degree of milling, particle size), solvent extraction time and temperature, and gas chromatographic parameters were studied. Particle size had no influence on 2-AP or hexanal recovered. One extraction solubilized ≈80% of the 2-AP and 56% of the hexanal present in milled rice. The optimum extraction method was assessed to require 0.3 g of ground brown or milled rice in methylene chloride held at 85°C for 2.5 hr. The complete gas chromatographic run requires ≈25 min, and 50 samples can ...