High-quality Italian rice cultivars: chemical indices of ageing and aroma quality

Abstract

The volatile fractions of six Italian high-quality rice cultivars were investigated by HS-SPME-GC-MS to define fingerprinting and identify chemical markers and/or indices of ageing and aroma quality. In particular, four non-aromatic (Carnaroli, Carnise, Cerere and Antares) and two aromatic (Apollo and Venere) rices, harvested in 2010 and 2011, were monitored over 12months. Twenty-five aroma components were considered and, despite considerable inter-annual variability, some of them showed similar trends over time, including 2-(E)-octenal as a marker of ageing for all cultivars, and heptanal, octanal and 2-ethyl hexanol as cultivar-specific indicators. The area ratios 2-acetyl-1-pyrroline/1-octen-3-ol, for Venere, and 3-methyl-1-butanol/2-methyl-1-butanol, for Apollo, were also found to act as ageing indices. Additional information on release of key-aroma compounds was also obtained from quantitation and its dependence on grain shape and chemical composition. Heptanal/1-octen-3-ol and heptanal/octanal ratios were also defined as characterising the aroma quality indices of the six Italian rice cultivars investigated.

Keywords: 1-Butanol, 2-methyl- (PubChem CID: 8723); 1-Butanol, 3-methyl- (PubChem CID: 31260); 1-Octen-3-ol (PubChem CID: 18827); 2(E)-Octenal (PubChem CID: 5283324); 2-Acetyl-pyrroline (PubChem CID: 522834); 2-Pentylfuran (PubChem CID: 19602); Ageing markers and indices; Aroma quality; Chemometrics; Cultivars; HS-SPME–GC–MS; Heptanal (PubChem CID: 8130); Hexanal (PubChem CID: 6184); Oct-(3E)-en-2-one (PubChem CID: 5363229); Octanal (PubChem CID: 454); Quantitation; Rice (Oryza sativa L.); Storage.