Effects of an Industrial Milling Process on Change of Headspace Volatiles in Yihchuan Aromatic Rice

Headspace volatiles of Yihchuan aromatic rice, a japonica rice cultivar, were extracted by a solid-phase microextraction (SPME) method and analyzed by GC and GC-MS. Effects of fiber types and an industrial milling process on the change of headspace volatiles were studied. Of the fiber types, divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS), polydimethylsiloxane/divinylbenzene (PDMS/DVB), and carboxen/polydimethylsiloxane (CAR/PDMS) were suggested for use in the analysis of headspace volatiles in terms of absorption or adsorption ability. Regarding the milling effect, the amount of total headspace volatiles from brown rice to white rice decreased approximate to 30%, and that of aldehydes and alcohols, the two largest groups of volatiles, decreased approximate to 20 and 15%, respectively. Comparatively, rice bran contained higher amounts of total headspace volatiles than milled rice grains.